Android之PopupWindow弹出对话框

Android的对话框常用的有两种：PopupWindow和AlertDialog。

popupWindow是一个阻塞式的弹出框，这就意味着在我们退出这个弹出框之前，程序会一直等待，，这就意味着在我们退出这个弹出框之前，程序会一直等待，

*这和AlertDialog不同哦，AlertDialog是非阻塞式弹出框，AlertDialog弹出的时候，后台可是还可以做其他事情的哦。

PopupWindow顾名思义为弹出菜单，不同于AlertDialog对话框，PopupWindow弹出的位置可以很多变化，按照有无偏移分，可以分为无偏移和偏移两种；按照参照类型不同又可以分为两种：相对某个控件（Anchor锚）的位置和父容器内部的相对位置。具体如下：

函数	简介
showAsDropDown(View anchor)	相对某个控件的位置（正左下方），无偏移
showAsDropDown(View anchor, int xoff, int yoff)	相对某个控件的位置，有偏移（正数表示下方右边，负数表示（上方左边））
showAtLocation(View parent, int gravity, int x, int y)	父容器容器相对位置，例如正中央Gravity.CENTER，下方Gravity.BOTTOM等

下面是运行程序截图：

dialog.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:Android="http://schemas.android.com/apk/res/android"
Android:orientation="vertical"
Android:layout_width="fill_parent"
Android:layout_height="fill_parent"
>
<TextView
Android:id="@+id/tv_tip"
Android:layout_width="fill_parent"
Android:layout_height="wrap_content"
Android:text="请输入内容："
/>

<EditText
Android:id="@+id/et_text"
Android:layout_width="fill_parent"
Android:layout_height="wrap_content"
></EditText>

<LinearLayout
Android:gravity="center_horizontal"
Android:layout_width="fill_parent"
Android:layout_height="fill_parent"
>
<Button
Android:id="@+id/bt_ok"
Android:text="确定"
Android:layout_width="100px"
Android:layout_height="50px"
/>

<Button
Android:id="@+id/bt_cancle"
Android:text="取消"
Android:layout_width="100px"
Android:layout_height="50px"
/>
</LinearLayout>
</LinearLayout>

import Android.app.Activity;
import Android.content.Context;
import Android.content.SharedPreferences.Editor;
import Android.os.Bundle;
import Android.util.Log;
import Android.view.Gravity;
import Android.view.LayoutInflater;
import Android.view.View;
import Android.view.View.OnClickListener;
import Android.view.ViewGroup.LayoutParams;
import Android.widget.Button;
import Android.widget.EditText;
import Android.widget.Gallery;
import Android.widget.PopupWindow;
import Android.widget.TextView;

public class PopupWindowTest extends Activity {//PopupWindow属于不阻塞的对话框，AlertDialog则是阻塞的。
private Button bt_popupWindow1;
private Button bt_popupWindow2;
private Button bt_popupWindow3;
private Button bt_popupWindow4;
private TextView tv_showText;
private PopupWindow popupWindow;
private int screenWidth;
private int screenHeight;
private int dialgoWidth;
private int dialgoheight;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

initView();
}

/**
* 初始化控件和响应事件
*/
private void initView() {
bt_popupWindow1 = (Button)findViewById(R.id.bt_PopupWindow1);
bt_popupWindow2 = (Button)findViewById(R.id.bt_PopupWindow2);
bt_popupWindow3 = (Button)findViewById(R.id.bt_PopupWindow3);
bt_popupWindow4 = (Button)findViewById(R.id.bt_PopupWindow4);
tv_showText = (TextView)findViewById(R.id.tv_showText);

bt_popupWindow1.setOnClickListener(new ClickEvent());
bt_popupWindow2.setOnClickListener(new ClickEvent());
bt_popupWindow3.setOnClickListener(new ClickEvent());
bt_popupWindow4.setOnClickListener(new ClickEvent());

}

/**
* 按钮点击事件处理
* @author Kobi
*
*/
private class ClickEvent implements OnClickListener {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
switch(v.getId()) {

case R.id.bt_PopupWindow1:  //以自己为Anchor，不偏移
getPopupWindow();
popupWindow.showAsDropDown(v);
break;

case R.id.bt_PopupWindow2:  //以自己为Anchor，偏移(screenWidth-dialgoWidth)/2, 0)--按钮正下方
getPopupWindow();
popupWindow.showAsDropDown(v, (screenWidth-dialgoWidth)/2, 0);
break;

case R.id.bt_PopupWindow3:  //以屏幕中心为参照，不偏移
getPopupWindow();
popupWindow.showAtLocation(findViewById(R.id.layout), Gravity.CENTER, 0, 0);
break;

case R.id.bt_PopupWindow4:  //以屏幕左下角为参照，偏移(screenWidth-dialgoWidth)/2, 0) --屏幕下方中央
getPopupWindow();
popupWindow.showAtLocation(findViewById(R.id.layout),
Gravity.BOTTOM, 0, 0);
break;

default:
break;
}
}

}

/**
* 创建PopupWindow
*/
protected void initPopuptWindow() {
// TODO Auto-generated method stub

View popupWindow_view = getLayoutInflater().inflate(    //获取自定义布局文件dialog.xml的视图
R.layout.dialog, null,false);

popupWindow = new PopupWindow(popupWindow_view, 200, 150, true);//创建PopupWindow实例

Button bt_ok = (Button)popupWindow_view.findViewById(R.id.bt_ok);   //dialog.xml视图里面的控件
Button bt_cancle = (Button)popupWindow_view.findViewById(R.id.bt_cancle);
final EditText et_text = (EditText)popupWindow_view.findViewById(R.id.et_text);

bt_ok.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
tv_showText.setText(et_text.getText()); //在标签里显示内容
popupWindow.dismiss();                  //对话框消失
}
});

bt_cancle.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
popupWindow.dismiss();
}
});

//获取屏幕和对话框各自高宽
screenWidth = PopupWindowTest.this.getWindowManager().getDefaultDisplay().getWidth();
screenHeight = PopupWindowTest.this.getWindowManager().getDefaultDisplay().getHeight();

dialgoWidth = popupWindow.getWidth();
dialgoheight = popupWindow.getHeight();

}

/*
* 获取PopupWindow实例
*/
private void getPopupWindow() {

if(null != popupWindow) {
popupWindow.dismiss();
return;
}else {
initPopuptWindow();
}
}

@Override
protected void onPause() {
// TODO Auto-generated method stub
super.onPause();
Log.e("ActivityState", "onPause");
}

@Override
protected void onResume() {
// TODO Auto-generated method stub
super.onResume();
Log.e("ActivityState", "onResume");
}

}