Android实现类似360,QQ管家那样的悬浮窗

一、前言： 

我手机从来不装这些东西，不过，有次看到同事的android手机上，有个QQ管家在桌面上浮着，同事拖动管家时，管家就变成一只鸟，桌面下方还有个弹弓，桌面顶部有只乌鸦，把管家也就是鸟拖动到弹弓那，然后，松手，鸟就飞出去。这个过程是动画过程，做的事，实际上是清楚内存。 

二：原理： 

其实，没什么原理，用到的就是WindowManager以及WindowManager.LayoutParams，对这个LayoutParams做文章，当设置为属性后，然后，创建一个View，将这个View添加到WindowManager中就行。 

复制代码 代码如下:

package com.chris.floats.window; 

import android.os.Bundle; 

import android.util.DisplayMetrics; 

import android.view.Gravity; 

import android.view.WindowManager; 

import android.app.Activity; 

import android.content.Context; 

public class MainActivity extends Activity { 

private static WindowManager mWindowMgr = null; 

private WindowManager.LayoutParams mWindowMgrParams = null; 

private static FloatsWindowView mFloatsWindowView = null; 

@Override 

protected void onCreate(Bundle savedInstanceState) { 

super.onCreate(savedInstanceState); 

setContentView(R.layout.activity_main); 

} 

/* 

* 显示应用主界面时，去除悬浮层 

*/ 

@Override 

public void onWindowFocusChanged(boolean hasFocus) { 

if(hasFocus){ 

if(mFloatsWindowView != null){ 

mWindowMgr.removeView(mFloatsWindowView); 

mFloatsWindowView = null; 

} 

}else{ 

getWindowLayout(); 

} 

} 

private void initParams(){ 

DisplayMetrics dm = getResources().getDisplayMetrics(); 

mWindowMgrParams.x = dm.widthPixels - 136; 

mWindowMgrParams.y = 300; 

mWindowMgrParams.width = 136; 

mWindowMgrParams.height = 136; 

} 

private void getWindowLayout(){ 

if(mFloatsWindowView == null){ 

mWindowMgr = (WindowManager)getBaseContext().getSystemService(Context.WINDOW_SERVICE); 

mWindowMgrParams = new WindowManager.LayoutParams(); 

/* 

* 2003 在指悬浮在所有界面之上 

* (4.0+系统中，在下拉菜单下面，而在2.3中，在上拉菜单之上) 

*/ 

mWindowMgrParams.type = 2003; 

mWindowMgrParams.format = 1; 

/* 

* 代码实际是wmParams.flags |= FLAG_NOT_FOCUSABLE; 

* 40的由来是wmParams的默认属性（32）+ FLAG_NOT_FOCUSABLE（8） 

*/ 

mWindowMgrParams.flags = 40; 

mWindowMgrParams.gravity = Gravity.LEFT | Gravity.TOP; 

initParams(); 

mFloatsWindowView = new FloatsWindowView(this); 

mWindowMgr.addView(mFloatsWindowView, mWindowMgrParams); 

} 

} 

} 

上面代码，主要在getWindowLayout函数中，最后两行就是创建一个View，并加入到WindowManager中。 

继承View的悬浮View： 

复制代码 代码如下:

package com.chris.floats.window; 

import android.content.Context; 

import android.content.Intent; 

import android.graphics.drawable.AnimationDrawable; 

import android.util.AttributeSet; 

import android.util.DisplayMetrics; 

import android.view.Gravity; 

import android.view.MotionEvent; 

import android.view.View; 

import android.view.ViewTreeObserver.OnPreDrawListener; 

import android.view.WindowManager; 

public class FloatsWindowView extends View { 

private Context mContext = null; 

private WindowManager mWindowMgr = null; 

private WindowManager.LayoutParams mWindowMgrParams = null; 

private AnimationDrawable mAnimationDrawable = null; 

private int iPosX = 0; 

private int iPosY = 0; 

private int iLastPosX = 0; 

private int iLastPosY = 0; 

private boolean bMoved = false; 

public FloatsWindowView(Context context) { 

this(context, null, 0); 

} 

public FloatsWindowView(Context context, AttributeSet attrs) { 

this(context, attrs, 0); 

} 

public FloatsWindowView(Context context, AttributeSet attrs, int defStyle) { 

super(context, attrs, defStyle); 

mContext = context; 

mWindowMgr = (WindowManager)getContext().getApplicationContext().getSystemService("window"); 

mWindowMgrParams = new WindowManager.LayoutParams(); 

initParams(); 

mAnimationDrawable = new AnimationDrawable(); 

for(int i = 0; i < 4; i++){ 

int id = getResources().getIdentifier("a"+ i, "drawable", mContext.getPackageName()); 

mAnimationDrawable.addFrame(getResources().getDrawable(id), 100); 

} 

mAnimationDrawable.setOneShot(false); 

this.setBackgroundDrawable(mAnimationDrawable); 

OnPreDrawListener listener = new OnPreDrawListener(){ 

@Override 

public boolean onPreDraw() { 

mAnimationDrawable.start(); 

return true; 

} 

}; 

this.getViewTreeObserver().addOnPreDrawListener(listener); 

} 

private void initParams(){ 

DisplayMetrics dm = getResources().getDisplayMetrics(); 

mWindowMgrParams.x = dm.widthPixels - 136; 

mWindowMgrParams.y = 300; 

mWindowMgrParams.width = 136; 

mWindowMgrParams.height = 136; 

} 

@Override 

public boolean onTouchEvent(MotionEvent event) { 

switch(event.getAction()){ 

case MotionEvent.ACTION_DOWN: 

iPosX = (int)event.getX(); 

iPosY = (int)event.getY(); 

bMoved = false; 

break; 

case MotionEvent.ACTION_MOVE: 

bMoved = true; 

iLastPosX = (int)event.getX(); 

iLastPosY = (int)event.getY(); 

updatePostion(iLastPosX - iPosX, iLastPosY - iPosY); 

break; 

case MotionEvent.ACTION_UP: 

if(!bMoved){ 

Intent it=new Intent(mContext, MainActivity.class); 

mContext.startActivity(it); 

} 

break; 

default: 

break; 

} 

return true; 

} 

private void updatePostion(int x, int y){ 

mWindowMgrParams.type = 2003; 

mWindowMgrParams.format = 1; 

mWindowMgrParams.flags = 40; 

mWindowMgrParams.gravity = Gravity.LEFT | Gravity.TOP; 

mWindowMgrParams.x += x; 

mWindowMgrParams.y += y; 

mWindowMgr.updateViewLayout(this, mWindowMgrParams); 

} 

} 

之所以将updatePosition中的参数与Activity中设置一样，是为了确保在MOVE时，造成相对位置的不一样，而导致闪砾，大家要是不理解，可以实验下。

三、小结： 

这篇文章实现了简单的悬浮窗口动画效果，如果要想做成像360,QQ管家那样，还需要一些其它的操作： 

1. 比如启动一个后台服务来监控系统信息； 

2. ACTION_DOWN时，修改悬浮窗口上的图片； 

3. ACTION_MOVE时窗口跟随； 

4. ACTION_UP时，创建一个线程，来完成释放后，向上运动的动画过程等； 

详细出处参考：http://www.jb51.net/article/37817.htm