第3天PopupWindow弹出菜单

PopupWindow

显示方法	显示位置
showAsDropDown(View anchor, int xoff, int yoff)	显示在anchor控件的下方
showAtLocation(View parent, int gravity, int x, int y)	显示在parent控件的某个位置

一.PopupWindow介绍

PopupWindow弹出窗体可以在任意位置弹出窗体，而对话框只能出现屏幕最中间。

二.如何自定义窗体

(1)构造方法：public PopupWindow (Context context)：context上下文对象
(2)必须设置的3大要素：
setContentView()：设置自定义布局
setWidth()：设置宽度
setHeight()：设置高度
(3)显示窗体：
a。显示在某个指定控件的下方
showAsDropDown(View anchor)：
showAsDropDown(View anchor, int xoff, int yoff)；//xoff和yoff都是偏移量
b。指定父视图，显示在父控件的某个位置（Gravity.TOP,Gravity.RIGHT等）
showAtLocation(View parent, int gravity, int x, int y)；
//gravity可以是Gravity.TOP、Gravity.BOTTOM、Gravity.LEFT、Gravity.RIGHT

三.实现微信QQ支付宝右上角加号弹出窗体

1.步骤流程：

步骤1.实例化PopupWindow对象
步骤2.设置自定义布局、宽度和高度
步骤3.指定位置显示： showAsDropDown() showAtLocation()

2代码：
（1）xml布局文件：activity_main2.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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=".Main2Activity"
    android:orientation="vertical"
    >
    <RelativeLayout
        android:background="#393A3F"
        android:layout_weight="1"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        >
        <TextView
            android:gravity="center_vertical"
            android:textColor="#fff"
            android:textSize="30sp"
            android:text="微信"
            android:layout_width="wrap_content"
            android:layout_height="match_parent" />
        <ImageView
            android:layout_alignParentRight="true"
            android:layout_marginRight="50dp"
            android:src="@drawable/search"
            android:layout_width="wrap_content"
            android:layout_height="match_parent" />
        <ImageView
            android:id="@+id/add"
            android:layout_alignParentRight="true"
            android:src="@drawable/add"
            android:layout_width="wrap_content"
            android:layout_height="match_parent" />
    </RelativeLayout>

   <ListView
       android:id="@+id/lv"
       android:layout_weight="8"
       android:layout_width="match_parent"
       android:layout_height="0dp"></ListView>

   <RadioGroup
       android:layout_weight="1"
       android:layout_width="match_parent"
       android:layout_height="0dp"
       android:orientation="horizontal">
       <RadioButton
           android:textAlignment="center"
           android:drawableTop="@drawable/selector1"
           android:button="@null"
           android:textSize="20sp"
           android:text="微信"
           android:textColor="@drawable/selector2"
           android:layout_weight="1"
           android:layout_width="0dp"
           android:layout_height="match_parent" />
       <RadioButton
           android:textAlignment="center"
           android:drawableTop="@drawable/selector1"
           android:button="@null"
           android:textSize="20sp"
           android:text="微信"
           android:textColor="@drawable/selector2"
           android:layout_weight="1"
           android:layout_width="0dp"
           android:layout_height="match_parent" />
       <RadioButton
           android:textAlignment="center"
           android:drawableTop="@drawable/selector1"
           android:button="@null"
           android:textSize="20sp"
           android:text="微信"
           android:textColor="@drawable/selector2"
           android:layout_weight="1"
           android:layout_width="0dp"
           android:layout_height="match_parent" />
       <RadioButton
           android:textAlignment="center"
           android:drawableTop="@drawable/selector1"
           android:button="@null"
           android:textSize="20sp"
           android:text="微信"
           android:textColor="@drawable/selector2"
           android:layout_weight="1"
           android:layout_width="0dp"
           android:layout_height="match_parent" />
   </RadioGroup>
</LinearLayout>

（2）自定义弹出窗体布局xml文件：layout_weixin_popupwindow.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:background="#45494A"
    android:orientation="vertical">
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <ImageView
            android:src="@drawable/chat"
            android:layout_weight="3"
            android:layout_width="0dp"
            android:layout_height="match_parent" />
        <TextView
            android:textColor="#fff"
            android:textSize="20sp"
            android:text="发起群聊"
            android:layout_weight="7"
            android:layout_width="0dp"
            android:layout_height="match_parent" />
    </LinearLayout>
    <View
        android:layout_width="match_parent"
        android:layout_height="5dp"
        android:background="#fff">
        
    </View>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <ImageView
            android:src="@drawable/chat"
            android:layout_weight="3"
            android:layout_width="0dp"
            android:layout_height="match_parent" />
        <TextView
            android:textColor="#fff"
            android:textSize="20sp"
            android:text="发起群聊"
            android:layout_weight="7"
            android:layout_width="0dp"
            android:layout_height="match_parent" />
    </LinearLayout>
    <View
        android:layout_width="match_parent"
        android:layout_height="5dp"
        android:background="#fff">
    </View>
</LinearLayout>

（3）Java代码：Main2Activity.java

public class Main2Activity extends AppCompatActivity {
    private ImageView imageView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //TODO 去除自带的bar
        supportRequestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_main2);
        imageView = (ImageView) findViewById(R.id.add);
        imageView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                show_popupwindow();
            }
        });
    }
    //弹出窗体
    public void show_popupwindow(){
        //TODO 1:实例化对象
        PopupWindow popupWindow = new PopupWindow(Main2Activity.this);
        //TODO 2：设置属性
        View view= LayoutInflater.from(this).inflate(R.layout.layout_weixin_popupwindow,null);
        popupWindow.setContentView(view);
        popupWindow.setHeight(ViewGroup.LayoutParams.WRAP_CONTENT);
        popupWindow.setWidth(600);
        //设置点击外部消失
        popupWindow.setOutsideTouchable(true);
        //TODO 3:展示
        popupWindow.showAsDropDown(imageView,-100,-100);
    }

}

四.底部弹出窗体

主要应用于抖音点击分享，打字弹出键盘等

(1)xml布局文件：activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:gravity="center">
    <Button
        android:onClick="click"
        android:text="弹出窗体"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
</LinearLayout>

(2)弹出窗体xml布局文件：layout3.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="#F0E8F0"
    android:orientation="vertical">
    <TextView
        android:id="@+id/camera_tv"
    android:textAlignment="center"
    android:textSize="30sp"
    android:text="拍照"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" />
    <View
        android:background="#969696"
        android:layout_width="match_parent"
        android:layout_height="5dp"></View>

    <TextView
        android:textAlignment="center"
        android:textSize="30sp"
        android:text="从手机相册选择"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <View
        android:background="#969696"
        android:layout_width="match_parent"
        android:layout_height="5dp"></View>
    <TextView
        android:textAlignment="center"
        android:textSize="30sp"
        android:text="保存图片"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <View
        android:background="#969696"
        android:layout_width="match_parent"
        android:layout_height="15dp"></View>
    <TextView
        android:textAlignment="center"
        android:textSize="30sp"
        android:text="取消"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</LinearLayout>

(3)java 代码：MainActivity.java

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void click(View view) {
        show_popupwindow();
    }
    //弹出窗体
    public void show_popupwindow(){
        //TODO 1:实例化对象
        PopupWindow popupWindow = new PopupWindow(MainActivity.this);
        //TODO 2：设置属性
        View view=LayoutInflater.from(this).inflate(R.layout.layout3,null);
        final TextView textView = view.findViewById(R.id.camera_tv);
        textView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(MainActivity.this, textView.getText().toString().trim(), Toast.LENGTH_SHORT).show();
            }
        });
	popupWindow.setContentView(view);
        popupWindow.setHeight(ViewGroup.LayoutParams.WRAP_CONTENT);
        popupWindow.setWidth(ViewGroup.LayoutParams.WRAP_CONTENT);
        //设置点击外部消失
        popupWindow.setOutsideTouchable(true);
      	//TODO 3:展示
        /**
         * @param parent 父布局
         * @param gravity gravity可以是Gravity.TOP、Gravity.BOTTOM、Gravity.LEFT、Gravity.RIGHT。。。。
         * @param x x轴偏移量
         * @param y y轴偏移量
         */
        View parent=LayoutInflater.from(MainActivity.this).inflate(R.layout.activity_main,null);
        popupWindow.showAtLocation(parent, Gravity.BOTTOM,0,0);
    }

}