【转】 android 悬浮窗口的拖动

package net.xsmile.fv;

import android.app.Application;
import android.view.WindowManager;

public class MyApplication extends Application {

/**
* 创建全局变量
* 全局变量一般都比较倾向于创建一个单独的数据类文件，并使用static静态变量
*
* 这里使用了在Application中添加数据的方法实现全局变量
* 注意在AndroidManifest.xml中的Application节点添加android:name=".MyApplication"属性
*
*/
private WindowManager.LayoutParams wmParams=new WindowManager.LayoutParams();

public WindowManager.LayoutParams getMywmParams(){
return wmParams;
}
}

package net.xsmile.fv;

import android.content.Context;
import android.util.Log;
import android.view.MotionEvent;
import android.view.WindowManager;
import android.widget.ImageView;

public class MyFloatView extends ImageView {
private float mTouchStartX;
private float mTouchStartY;
private float x;
private float y;

private WindowManager wm=(WindowManager)getContext().getApplicationContext().getSystemService("window");

//此wmParams为获取的全局变量，用以保存悬浮窗口的属性
private WindowManager.LayoutParams wmParams = ((MyApplication)getContext().getApplicationContext()).getMywmParams();

public MyFloatView(Context context) {
super(context);
// TODO Auto-generated constructor stub
}

@Override
public boolean onTouchEvent(MotionEvent event) {

//获取相对屏幕的坐标，即以屏幕左上角为原点
x = event.getRawX();
y = event.getRawY()-25;   //25是系统状态栏的高度
Log.i("currP", "currX"+x+"====currY"+y);
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
//获取相对View的坐标，即以此View左上角为原点
mTouchStartX =  event.getX();
mTouchStartY =  event.getY();

Log.i("startP", "startX"+mTouchStartX+"====startY"+mTouchStartY);

break;
case MotionEvent.ACTION_MOVE:
updateViewPosition();
break;

case MotionEvent.ACTION_UP:
updateViewPosition();
mTouchStartX=mTouchStartY=0;
break;
}
return true;
}

private void updateViewPosition(){
//更新浮动窗口位置参数
wmParams.x=(int)( x-mTouchStartX);
wmParams.y=(int) (y-mTouchStartY);
wm.updateViewLayout(this, wmParams);

}

}

package net.xsmile.fv;

import android.app.Activity;
import android.graphics.PixelFormat;
import android.os.Bundle;
import android.view.Gravity;
import android.view.WindowManager;
import android.view.WindowManager.LayoutParams;

public class MyFloatViewActivity extends Activity {
/** Called when the activity is first created. */

private WindowManager wm=null;
private WindowManager.LayoutParams wmParams=null;

private MyFloatView myFV=null;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//创建悬浮窗口
createView();

}

private void createView(){
myFV=new MyFloatView(getApplicationContext());
myFV.setImageResource(R.drawable.icon);
//获取WindowManager
wm=(WindowManager)getApplicationContext().getSystemService("window");
//设置LayoutParams(全局变量）相关参数
wmParams = ((MyApplication)getApplication()).getMywmParams();

/**
*以下都是WindowManager.LayoutParams的相关属性
* 具体用途可参考SDK文档
*/
wmParams.type=LayoutParams.TYPE_PHONE;   //设置window type
wmParams.format=PixelFormat.RGBA_8888;   //设置图片格式，效果为背景透明

//设置Window flag
wmParams.flags=LayoutParams.FLAG_NOT_TOUCH_MODAL
| LayoutParams.FLAG_NOT_FOCUSABLE;
/*
* 下面的flags属性的效果形同“锁定”。
* 悬浮窗不可触摸，不接受任何事件,同时不影响后面的事件响应。
wmParams.flags=LayoutParams.FLAG_NOT_TOUCH_MODAL
| LayoutParams.FLAG_NOT_FOCUSABLE
| LayoutParams.FLAG_NOT_TOUCHABLE;
*/

wmParams.gravity=Gravity.LEFT|Gravity.TOP;   //调整悬浮窗口至左上角
//以屏幕左上角为原点，设置x、y初始值
wmParams.x=0;
wmParams.y=0;

//设置悬浮窗口长宽数据
wmParams.width=40;
wmParams.height=40;

//显示myFloatView图像
wm.addView(myFV, wmParams);

}

@Override
public void onDestroy(){
super.onDestroy();
//在程序退出(Activity销毁）时销毁悬浮窗口
wm.removeView(myFV);
}

}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="net.xsmile.fv"
android:versionCode="1"
android:versionName="1.0">
<application android:name=".MyApplication" android:icon="@drawable/icon" android:label="@string/app_name">
<activity android:name=".MyFloatViewActivity"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>

</application>

<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />

</manifest>