718 lines
25 KiB
Markdown
718 lines
25 KiB
Markdown
# 第三章：Android常见界面控件
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## 3.1简单控件
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### 1.TextView（显示文本信息）
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| 属性名称 | 功能描述 |
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| :----------------------: | :----------------------------------------------------------: |
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| android:layout_width | 设置 TextView控件的宽度 |
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| android:layout_height | 设置 TextView控件的高度 |
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| androidid | 设置 TextView 控件的唯一标识 |
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| android:background | 设置 TextView 控件的背景 |
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| android:layout_margin | 设置当前控件与屏幕边界或周围控件、布局的距离 |
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| android:padding | 设置 TextView控件与该控件中内容的距离 |
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| android:text | 设置文本内容 |
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| android:textColor | 设置文字显示的颜色 |
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| android:textSize | 设置文字大小，推荐单位为 5p，如android:textSize = "15sp" |
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| android:gravity | 设置文本内容的位置，如设置成“center”，文本将居中显示 |
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| android:maxLength | 设置文本最大长度，超出此长度的文本不显示。如android:maxLength - "10" |
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| android:lines | 设置文本的行数，超出此行数的文本不显示 |
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| android:maxLines | 设置文本的最大行数，超出此行数的文本不显示 |
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| android:ellipsize | 设置当文本超出TextView规定的范围的显示方式。属性值可选为"start”, "middle" 和"end"，分别表示当文本超出TextView规定的范围时，在文本开始、中间或者末尾显示省略号“----” |
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| android:drawableTop | 在文本的顶部显示图像，该图像资源可以放在 res/drawable 相应分辨率的目录下，通过“@drawable/文件名”调用。类似的属性有 android:drawableBottorm、android:drawableLefi、android:drawableRight |
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| android:lineSpacingExtra | 设置文本的行间距 |
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| android:textStyle | 设置文本样式，如bold (租体), italic (斜体), normal (正常) |
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### 2.Button（按钮）
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（1）在布局文件中指定 onClick 属性的方式设置点击事件
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```xml
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<!-- activity_main.xml 文件-->
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<Button
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android:layout_width="match_parent"
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android:layout_height="wrap_content"
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android:onClick="click"
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android:text="onClick属性" />
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```
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```java
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// MainActivity.java 文件
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public void click(View view) {
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System.out.println("我是通过onClick属性完成的单击事件");
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}
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```
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（2）使用匿名内部类的方式设置点击事件
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```xml
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<!-- activity_main.xml 文件-->
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<Button
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android:id="@+id/btn_two"
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android:layout_width="match_parent"
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android:layout_height="wrap_content"
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android:text="匿名内部类" />
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```
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```java
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// MainActivity.java 文件
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public class MainActivity extends AppCompatActivity {
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Button btn_two;
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@Override
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protected void onCreate(Bundle savedInstanceState) {
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super.onCreate(savedInstanceState);
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setContentView(R.layout.activity_main);
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btn_two = findViewById(R.id.btn_two);
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btn_two.setOnClickListener(new View.OnClickListener() {
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@Override
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public void onClick(View view) {
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System.out.println("我是通过匿名内部类完成的单击事件");
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}
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});
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}
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}
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```
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（3）Activity 实现 OnClickListener 接口的方式设置点击事件
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```xml
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<!-- activity_main.xml 文件-->
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<Button
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android:id="@+id/btn_three"
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android:layout_width="match_parent"
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android:layout_height="wrap_content"
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android:text="接口实现" />
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```
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```java
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public class MainActivity extends AppCompatActivity implements View.OnClickListener {
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Button btn_three;
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@Override
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protected void onCreate(Bundle savedInstanceState) {
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super.onCreate(savedInstanceState);
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setContentView(R.layout.activity_main);
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btn_three=findViewById(R.id.btn_three);
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btn_three.setOnClickListener(this);
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}
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@Override
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public void onClick(View view) {
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System.out.println("我是通过实现接口的方式完成的单击事件");
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}
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}
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```
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### 3.EditText（编辑框）
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| 属性姓名 | 功能描述 |
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| :------------------------: | :----------------------------------------------------: |
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| android:hint | 控件中内容为空时显示的提示文本信息 |
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| android:textColorHint | 控件中内容为空时显示的提示文本信息的颜色 |
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| android:password | 输人文本框中的内容显示为“-” |
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| android:minLines | 设置文本的最小行数 |
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| androidiscrollHorizontally | 设置文本信息超出 EdifText 的宽度情况下，是否出现横拉条 |
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| android:editable | 设置是否可编辑 |
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| android:phoneNumber | 设置输人文本框中的内容只能是数字 |
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### 4.Image View（图片）
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| 属性名称 | 功能描述 |
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| :-------------------: | :---------------------------------------------: |
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| android:layout_width | 设置 ImageView 控件的宽度 |
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| android:layout_height | 设置 ImageView控件的高度 |
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| android:id | 设置ImageView控件的唯一标识 |
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| android:background | 设置 ImageView 控件的背景 |
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| android:layout_margin | 设置当前控件与屏幕边界或周围控件的距离 |
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| android:src | 设置ImageView控件需要显示的图片资源 |
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| android:scaleType | 将图片资源缩放或移动，以适应ImageView控件的宽高 |
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| android:tint | 将图片渲染成指定的颜色 |
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### 5.RadioButton（单选按钮）
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```xml
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<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
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xmlns:app="http://schemas.android.com/apk/res-auto"
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xmlns:tools="http://schemas.android.com/tools"
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android:layout_width="match_parent"
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android:layout_height="match_parent"
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android:orientation="vertical">
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<TextView
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android:layout_width="wrap_content"
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android:layout_height="wrap_content"
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android:text="请选择你的性别" />
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<RadioGroup
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android:id="@+id/rg"
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android:layout_width="wrap_content"
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android:layout_height="wrap_content">
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<RadioButton
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android:id="@+id/rb_1"
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android:layout_width="wrap_content"
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android:layout_height="wrap_content"
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android:text="男" />
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<RadioButton
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android:id="@+id/rb_2"
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android:layout_width="wrap_content"
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android:layout_height="wrap_content"
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android:text="女" />
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<RadioButton
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android:id="@+id/rb_3"
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android:layout_width="wrap_content"
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android:layout_height="wrap_content"
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android:text="保密" />
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</RadioGroup>
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<TextView
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android:id="@+id/tv"
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android:layout_width="wrap_content"
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android:layout_height="wrap_content"
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android:text="此处显示您的性别：" />
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</LinearLayout>
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```
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```java
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public class MainActivity extends AppCompatActivity {
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RadioGroup rg;
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RadioButton rb1, rb2;
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TextView tv;
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@Override
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protected void onCreate(Bundle savedInstanceState) {
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super.onCreate(savedInstanceState);
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setContentView(R.layout.activity_main);
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init();
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// 为单选按钮组添加单击事件
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rg.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
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@Override
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public void onCheckedChanged(RadioGroup radioGroup, int i) {
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// radioGroup 代表的是单选按钮组
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// i 代表的是单选按钮
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switch (i) {
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case R.id.rb_1:
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tv.setText("您的性别是：男");
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break;
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case R.id.rb_2:
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tv.setText("您的性别是：女");
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break;
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case R.id.rb_3:
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tv.setText("您的性别是：未知");
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break;
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}
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}
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});
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}
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// 初始化所有的控件
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void init() {
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rg = findViewById(R.id.rg);
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rb1 = findViewById(R.id.rb_1);
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rb1 = findViewById(R.id.rb_2);
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rb1 = findViewById(R.id.rb_3);
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tv = findViewById(R.id.tv);
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}
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}
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```
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演示：
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### 6.CheckBox（复选框）
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```xml
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<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
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xmlns:app="http://schemas.android.com/apk/res-auto"
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xmlns:tools="http://schemas.android.com/tools"
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android:layout_width="match_parent"
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android:layout_height="match_parent"
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tools:context=".MainActivity"
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android:orientation="vertical">
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<TextView
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android:layout_width="wrap_content"
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android:layout_height="wrap_content"
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android:text="请选择您的爱好：" />
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<CheckBox
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android:id="@+id/cb_1"
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android:layout_width="wrap_content"
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android:layout_height="wrap_content"
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android:text="看书"/>
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<CheckBox
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android:id="@+id/cb_2"
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android:layout_width="wrap_content"
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android:layout_height="wrap_content"
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android:text="看视频"/>
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<CheckBox
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android:id="@+id/cb_3"
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android:layout_width="wrap_content"
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android:layout_height="wrap_content"
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android:text="看文档"/>
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<TextView
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android:id="@+id/tv"
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android:layout_width="wrap_content"
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android:layout_height="wrap_content"
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android:text="您的爱好是：" />
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</LinearLayout>
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```
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```java
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public class MainActivity extends AppCompatActivity implements CompoundButton.OnCheckedChangeListener {
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CheckBox cb1, cb2, cb3;
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TextView tv;
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String hobbys="您的爱好是：";
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@Override
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protected void onCreate(Bundle savedInstanceState) {
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super.onCreate(savedInstanceState);
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setContentView(R.layout.activity_main);
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init();
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// 为每一个复选框添加一个单击事件
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cb1.setOnCheckedChangeListener(this);
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cb2.setOnCheckedChangeListener(this);
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cb3.setOnCheckedChangeListener(this);
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}
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void init() {
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cb1 = findViewById(R.id.cb_1);
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cb2 = findViewById(R.id.cb_2);
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cb3 = findViewById(R.id.cb_3);
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tv = findViewById(R.id.tv);
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}
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@Override
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public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
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// compoundButton 代表的是状态被改变的复选框
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// b 代表的是状态 1.选中 2.未选中
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String motion = compoundButton.getText().toString();
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if (b == true) {
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// 如果复选框被选中，需要将复选框中的文本信息添加到 tv 中
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if (!hobbys.contains(motion)){
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hobbys=hobbys+motion;
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tv.setText(hobbys);
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}
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} else {
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// 如果复选框被取消，需要将复选框中的文本信息删除掉
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if(hobbys.contains(motion)){
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hobbys=hobbys.replace(motion,"");
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tv.setText(hobbys);
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}
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}
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}
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}
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```
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演示：
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### 7.Toast（信息提醒机制）
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```xml
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<?xml version="1.0" encoding="utf-8"?>
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<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
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android:layout_width="match_parent"
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android:layout_height="match_parent">
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<RadioGroup
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android:id="@+id/rg"
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android:layout_width="wrap_content"
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android:layout_height="wrap_content">
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<RadioButton
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android:id="@+id/rb_1"
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android:layout_width="wrap_content"
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android:layout_height="wrap_content"
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android:text="男" />
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<RadioButton
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android:id="@+id/rb_2"
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android:layout_width="wrap_content"
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android:layout_height="wrap_content"
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android:text="女" />
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</RadioGroup>
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</LinearLayout>
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```
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```java
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public class ToastActivity extends AppCompatActivity {
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RadioGroup rg;
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RadioButton rb1,rb2;
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@Override
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protected void onCreate(Bundle savedInstanceState) {
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super.onCreate(savedInstanceState);
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// 页面关联
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setContentView(R.layout.toast);
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// 初始化
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init();
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// 添加事件
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rg.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
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@Override
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public void onCheckedChanged(RadioGroup radioGroup, int i) {
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if (i==R.id.rb_1){
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Toast.makeText(ToastActivity.this,"您的性别是男",Toast.LENGTH_LONG).show();
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}else{
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Toast.makeText(ToastActivity.this,"您的性别是女",Toast.LENGTH_LONG).show();
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}
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}
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});
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}
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void init(){
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rg=findViewById(R.id.rg);
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rb1=findViewById(R.id.rb_1);
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rb2=findViewById(R.id.rb_2);
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}
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}
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```
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演示：
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## 3.2AlertDialog对话框使用
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### 3.2.2普通对话框
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通过调用 `setMessage()`方法设置
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```java
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setMessage(ChaeSequence message)
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```
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```java
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public class MainActivity extends AppCompatActivity {
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// 重写onBackPressed()----单击回退键时调用的方法
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@Override
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protected void onCreate(Bundle savedInstanceState) {
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super.onCreate(savedInstanceState);
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setContentView(R.layout.activity_main);
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}
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@Override
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public void onBackPressed() {
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// 1.创建静态内部类对象
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AlertDialog.Builder builder = new AlertDialog.Builder(this);
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// 2．创建对话框的标题区域----标题图标 标题名称
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builder.setTitle("普通对话框");
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builder.setIcon(R.mipmap.ic_launcher);
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// 3．创建对话框的内容区域
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builder.setMessage("您确认退出程序吗？");
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// 4．创建对话框的按钮区域
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builder.setPositiveButton("确认", new DialogInterface.OnClickListener() {
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@Override
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public void onClick(DialogInterface dialogInterface, int i) {
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Toast.makeText(MainActivity.this, "您单击了确认按钮", Toast.LENGTH_LONG).show();
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dialogInterface.dismiss();
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MainActivity.this.finish();
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}
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});
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builder.setNegativeButton("取消", new DialogInterface.OnClickListener() {
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@Override
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public void onClick(DialogInterface dialogInterface, int i) {
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Toast.makeText(MainActivity.this, "您单击了取消按钮", Toast.LENGTH_LONG).show();
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dialogInterface.dismiss();
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}
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});
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// 5．创建对话框对象
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AlertDialog dialog = builder.create();
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// 6．显示对话框
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dialog.show();
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}
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}
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```
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### 3.2.3单选对话框
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```xml
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<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
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xmlns:app="http://schemas.android.com/apk/res-auto"
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xmlns:tools="http://schemas.android.com/tools"
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android:layout_width="match_parent"
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android:layout_height="match_parent"
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tools:context=".MainActivity"
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android:orientation="vertical">
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<TextView
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android:id="@+id/tv"
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android:layout_width="match_parent"
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android:layout_height="wrap_content"
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android:gravity="center"
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android:text="今天课程真好"
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android:textSize="20sp" />
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<Button
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android:id="@+id/btn"
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android:layout_width="wrap_content"
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android:layout_height="wrap_content"
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android:layout_gravity="center"
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android:text="设置字体大小" />
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</LinearLayout>
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```
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```java
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public class MainActivity extends AppCompatActivity implements View.OnClickListener {
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// 2.定义成员变量
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Button btn;
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TextView tv;
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int textSize = 1;
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int[] textsizeArr = {10, 20, 30, 40, 50};
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@Override
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protected void onCreate(Bundle savedInstanceState) {
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super.onCreate(savedInstanceState);
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setContentView(R.layout.activity_main);
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// 1.初始化
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init();
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// 3.为控件绑定事件
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btn.setOnClickListener(this);
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}
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void init() {
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tv = findViewById(R.id.tv);
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btn = findViewById(R.id.btn);
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}
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@Override
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public void onClick(View view) {
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// 创建对话框
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// 1.创建静态内部类对象
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AlertDialog.Builder builder = new AlertDialog.Builder(this);
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// 2.创建标题
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builder.setTitle("单选对话框");
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builder.setIcon(R.mipmap.ic_launcher);
|
||
// 3.创建内部区域
|
||
builder.setSingleChoiceItems(new String[]{"小号", "默认", "中等", "大号", "超大号"}, textSize, new DialogInterface.OnClickListener() {
|
||
@Override
|
||
public void onClick(DialogInterface dialogInterface, int i) {
|
||
textSize = i;
|
||
Toast.makeText(MainActivity.this, "您单击了按钮", Toast.LENGTH_LONG).show();
|
||
|
||
}
|
||
});
|
||
// 4.创建按钮区域
|
||
builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
|
||
@Override
|
||
public void onClick(DialogInterface dialogInterface, int i) {
|
||
|
||
tv.setTextSize(textsizeArr[textSize]);
|
||
dialogInterface.dismiss();
|
||
}
|
||
});
|
||
builder.setNegativeButton("取消", null);
|
||
// 5.创建对话框
|
||
AlertDialog dialog = builder.create();
|
||
// 6.显示对话框
|
||
dialog.show();
|
||
}
|
||
}
|
||
```
|
||
|
||
|
||
|
||
### 3.2.4多选对话框
|
||
|
||
```xml
|
||
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
|
||
xmlns:app="http://schemas.android.com/apk/res-auto"
|
||
xmlns:tools="http://schemas.android.com/tools"
|
||
android:layout_width="match_parent"
|
||
android:layout_height="match_parent"
|
||
tools:context=".MainActivity">
|
||
|
||
<Button
|
||
android:id="@+id/btn"
|
||
android:layout_width="wrap_content"
|
||
android:layout_height="wrap_content"
|
||
android:text="请选择爱好"
|
||
app:layout_constraintBottom_toBottomOf="parent"
|
||
app:layout_constraintEnd_toEndOf="parent"
|
||
app:layout_constraintStart_toStartOf="parent"
|
||
app:layout_constraintTop_toTopOf="parent" />
|
||
</androidx.constraintlayout.widget.ConstraintLayout>
|
||
```
|
||
|
||
```java
|
||
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
|
||
String[] str = {"看代码", "敲代码", "改代码"};
|
||
boolean[] str1 = {false, true, false};
|
||
|
||
@Override
|
||
protected void onCreate(Bundle savedInstanceState) {
|
||
super.onCreate(savedInstanceState);
|
||
setContentView(R.layout.activity_main);
|
||
findViewById(R.id.btn).setOnClickListener(this);
|
||
|
||
}
|
||
|
||
@Override
|
||
public void onClick(View view) {
|
||
// 创建对话框
|
||
AlertDialog dialog = new AlertDialog.Builder(this)
|
||
.setTitle("多选对话框")
|
||
.setIcon(R.mipmap.ic_launcher)
|
||
.setMultiChoiceItems(str, str1, new DialogInterface.OnMultiChoiceClickListener() {
|
||
@Override
|
||
public void onClick(DialogInterface dialogInterface, int i, boolean b) {
|
||
str1[i] = b;
|
||
}
|
||
})
|
||
.setPositiveButton("确定", new DialogInterface.OnClickListener() {
|
||
@Override
|
||
public void onClick(DialogInterface dialogInterface, int i) {
|
||
StringBuffer stringBuffer = new StringBuffer();
|
||
for (int j = 0; j < str1.length; j++) {
|
||
if (str1[j]) {
|
||
stringBuffer.append(str[j]).append("");
|
||
}
|
||
}
|
||
if (stringBuffer != null) {
|
||
Toast.makeText(MainActivity.this, stringBuffer, Toast.LENGTH_SHORT).show();
|
||
}
|
||
}
|
||
})
|
||
.setNegativeButton("取消", null)
|
||
.create();
|
||
dialog.show();
|
||
}
|
||
}
|
||
```
|
||
|
||
|
||
|
||
## 3.3 ListView的使用
|
||
|
||
```xml
|
||
<RelativeLayout
|
||
xmlns:android="http://schemas.android.com/apk/res/android"
|
||
android:layout_width="match_parent"
|
||
android:layout_height="match_parent"
|
||
android:padding="16dp">
|
||
|
||
<ImageView
|
||
android:id="@+id/iv"
|
||
android:layout_width="120dp"
|
||
android:layout_height="90dp"
|
||
android:layout_centerVertical="true" />
|
||
|
||
<RelativeLayout
|
||
android:layout_width="wrap_content"
|
||
android:layout_height="wrap_content"
|
||
android:layout_centerVertical="true"
|
||
android:layout_marginLeft="10dp"
|
||
android:layout_toRightOf="@+id/iv">
|
||
|
||
<TextView
|
||
android:id="@+id/title"
|
||
android:layout_width="wrap_content"
|
||
android:layout_height="wrap_content"
|
||
android:text="桌子"
|
||
android:textColor="#000000"
|
||
android:textSize="20sp" />
|
||
|
||
<TextView
|
||
android:id="@+id/tv_price"
|
||
android:layout_width="wrap_content"
|
||
android:layout_height="wrap_content"
|
||
android:layout_below="@+id/title"
|
||
android:layout_marginTop="10dp"
|
||
android:text="价格："
|
||
android:textColor="#FF8F03"
|
||
android:textSize="20sp" />
|
||
|
||
<TextView
|
||
android:id="@+id/price"
|
||
android:layout_width="wrap_content"
|
||
android:layout_height="wrap_content"
|
||
android:layout_below="@+id/title"
|
||
android:layout_marginTop="10dp"
|
||
android:layout_toRightOf="@+id/tv_price"
|
||
android:text="1000"
|
||
android:textColor="#FF8F03"
|
||
android:textSize="20sp" />
|
||
</RelativeLayout>
|
||
</RelativeLayout>
|
||
```
|
||
|
||
```java
|
||
public class MainActivity extends AppCompatActivity {
|
||
// 1.准备数据
|
||
int[] icons = {R.drawable.apple, R.drawable.cake, R.drawable.kiwifruit, R.drawable.scarf, R.drawable.table, R.drawable.wireclothes};
|
||
String[] titles = {"苹果", "蛋糕", "猕猴桃", "围巾", "桌子", "毛衣"};
|
||
String[] prices = {"320元", "10元/kg", "300元", "10元/kg", "2800元", "1600元"};
|
||
|
||
// 2.准备控件
|
||
TextView textView;
|
||
ListView listView;
|
||
|
||
@Override
|
||
protected void onCreate(Bundle savedInstanceState) {
|
||
super.onCreate(savedInstanceState);
|
||
setContentView(R.layout.activity_main);
|
||
setContentView(R.layout.activity_main);
|
||
listView = findViewById(R.id.lv);
|
||
|
||
MyAdapter myAdapter = new MyAdapter();
|
||
listView.setAdapter(myAdapter);
|
||
}
|
||
|
||
class MyAdapter extends BaseAdapter {
|
||
|
||
@Override
|
||
public int getCount() {
|
||
return titles.length;
|
||
}
|
||
|
||
@Override
|
||
public Object getItem(int i) {
|
||
return null;
|
||
}
|
||
|
||
@Override
|
||
public long getItemId(int i) {
|
||
return 0;
|
||
}
|
||
|
||
@Override
|
||
public View getView(int i, View view, ViewGroup viewGroup) {
|
||
ViewHolder holder = null;
|
||
// 找控件
|
||
if (view == null) {
|
||
view = View.inflate(MainActivity.this, R.layout.list_item, null);
|
||
holder = new ViewHolder();
|
||
holder.title = view.findViewById(R.id.title);
|
||
holder.price = view.findViewById(R.id.price);
|
||
holder.iv = view.findViewById(R.id.iv);
|
||
view.setTag(holder);
|
||
} else {
|
||
holder = (ViewHolder) view.getTag();
|
||
}
|
||
// 为控件设置内容
|
||
holder.title.setText(titles[i]);
|
||
holder.price.setText(prices[i]);
|
||
holder.iv.setBackgroundResource(icons[i]);
|
||
return view;
|
||
}
|
||
}
|
||
|
||
class ViewHolder {
|
||
TextView title, price;
|
||
ImageView iv;
|
||
}
|
||
}
|
||
```
|
||
|
||
 |