PopupWindow的使用简介

一、简介

PopupWindow一般用于View控件周边的弹出窗口。

public PopupWindow (View contentView, int width, int height, boolean focusable)

创建一个新的弹出窗口可以显示contentView。窗户的尺寸必须传递给构造函数。

二、使用

1.创建弹出窗口popup_widow.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="match_parent"
    android:orientation="vertical" >
    
    <RadioButton
         android:paddingLeft="10dp"
        android:paddingRight="15dp"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:text="@string/str_hdmi14"
        android:textColor="@color/white"
        android:textSize="32sp" 
        android:button="@drawable/radio_btn"
        android:background="@drawable/xxx"/>
    
    <RadioButton
        android:paddingLeft="10dp"
        android:paddingRight="15dp"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:text="@string/str_hdmi20"
        android:textColor="@color/white"
        android:textSize="32sp" 
        android:button="@drawable/radio_btn"
        android:background="@drawable/xxx"/>

</LinearLayout>

2.在java代码中用LayoutInflater加载该窗口布局文件

View rootView =  LayoutInflater.from(mContext).inflate(
		R.layout.popup_window, null);

3.创建PopupWindow对象

 PopupWindow popupWindow = new PopupWindow(rootView,300, 200, true);

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4.设置PopupWindow的动画风格（可选）

popupWindow.setAnimationStyle(R.style.popup_window_anim);

4.1在values/style.xml定义动画风格

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <style name="popup_window_anim">
        <item name="android:windowEnterAnimation">@anim/popup_window_show</item>
        <item name="android:windowExitAnimation">@anim/popup_window_hide</item>
    </style>
</resources>

4.2 弹出动画 anim/pop_window_show.xml

<?xml version="1.0" encoding="utf-8"?>
<set  xmlns:android="http://schemas.android.com/apk/res/android">
	<scale android:interpolator="@android:anim/accelerate_decelerate_interpolator"
	          android:fromXScale="1.0"
	          android:toXScale="1.0"
	          android:fromYScale="0.0"
	          android:toYScale="1.0"
	          android:fillAfter="false"
	          android:duration="200">
	</scale>
</set>

4.3消失动画 anim/pop_window_hide.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
    <scale android:interpolator="@android:anim/accelerate_decelerate_interpolator"
              android:fromXScale="1.0"
              android:toXScale="1.0"
              android:fromYScale="1.0"
              android:toYScale="0.0"
              android:fillAfter="false"
              android:duration="200">
    </scale>
</set>

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5.显示PopupWindow

 popupWindow.showAsDropDown(btn ,xOff ,yOff);

参数：

btn： 在btn这个View控件周边弹出

xOff：x轴的偏移

yOff：y轴的偏移

注：如xOff = 0; yOff=0;则窗口在btn正下弹出（左边缘对齐）

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