WindowManager实现悬浮窗口&可自由移动的悬浮窗口

推荐安卓开发神器（里面有各种UI特效和android代码库实例）

Android中悬浮窗口的实现原理和示例代码
http://www.xsmile.net/?p=404

调用WindowManager，并设置WindowManager.LayoutParams的相关属性，通过WindowManager的addView方法创建View，这样产生出来的View根据WindowManager.LayoutParams属性不同，效果也就不同了。比如创建系统顶级窗口，实现悬浮窗口效果！

WindowManager的方法很简单，基本用到的就三个addView，removeView，updateViewLayout。

而WindowManager.LayoutParams的属性就多了，非常丰富，具体请查看SDK文档。这里给出Android中的WindowManager.java源码，可以具体看一下。
WindowManager 的源码地址：
http://www.netmite.com/android/mydroid/frameworks/base/core/java/android/view/WindowManager.java

以下代码请仅供演示：

public class myFloatView extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Button bb=new Button(getApplicationContext());
        WindowManager wm=(WindowManager)getApplicationContext().getSystemService("window");
        WindowManager.LayoutParams wmParams = new WindowManager.LayoutParams();
        wmParams.type=2002;  //type是关键，这里的2002表示系统级窗口，你也可以试试2003。
        wmParams.format=1;
        /**
         *这里的flags也很关键
         *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）
         */
        wmParams.flags=40;
        wmParams.width=40;
        wmParams.height=40;
        wm.addView(bb, wmParams);//创建View
    }
}

PS：本代码在Android2.3下测试无错（从API Level来看，实际上android1.5都可行）！另外别忘了在AndroidManifest.xml文件中加入如下权限：

 

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

关于代码中wmParams.type的值的问题，下面给出一些数值参考：
/**
         * Window type: the status bar.  There can be only one status bar
         * window; it is placed at the top of the screen, and all other
         * windows are shifted down so they are below it.
         */
        public static final int TYPE_STATUS_BAR         = FIRST_SYSTEM_WINDOW;
   
        /**
         * Window type: the search bar.  There can be only one search bar
         * window; it is placed at the top of the screen.
         */
        public static final int TYPE_SEARCH_BAR         = FIRST_SYSTEM_WINDOW+1;
   
        /**
         * Window type: phone.  These are non-application windows providing
         * user interaction with the phone (in particular incoming calls).
         * These windows are normally placed above all applications, but behind
         * the status bar.
         */
        public static final int TYPE_PHONE              = FIRST_SYSTEM_WINDOW+2;
   
        /**
         * Window type: system window, such as low power alert. These windows
         * are always on top of application windows.
         */
        public static final int TYPE_SYSTEM_ALERT       = FIRST_SYSTEM_WINDOW+3;
       
        /**
         * Window type: keyguard window.
         */
        public static final int TYPE_KEYGUARD           = FIRST_SYSTEM_WINDOW+4;
       
        /**
         * Window type: transient notifications.
         */
        public static final int TYPE_TOAST              = FIRST_SYSTEM_WINDOW+5;
       
        /**
         * Window type: system overlay windows, which need to be displayed
         * on top of everything else.  These windows must not take input
         * focus, or they will interfere with the keyguard.
         */
        public static final int TYPE_SYSTEM_OVERLAY     = FIRST_SYSTEM_WINDOW+6;
       
        /**
         * Window type: priority phone UI, which needs to be displayed even if
         * the keyguard is active.  These windows must not take input
         * focus, or they will interfere with the keyguard.
         */
        public static final int TYPE_PRIORITY_PHONE     = FIRST_SYSTEM_WINDOW+7;
       
        /**
         * Window type: panel that slides out from the status bar
         */
        public static final int TYPE_STATUS_BAR_PANEL   = FIRST_SYSTEM_WINDOW+8;
       
        /**
         * Window type: panel that slides out from the status bar
         */
        public static final int TYPE_SYSTEM_DIALOG      = FIRST_SYSTEM_WINDOW+8;
   
        /**
         * Window type: dialogs that the keyguard shows
         */
        public static final int TYPE_KEYGUARD_DIALOG    = FIRST_SYSTEM_WINDOW+9;
       
        /**
         * Window type: internal system error windows, appear on top of
         * everything they can.
         */
        public static final int TYPE_SYSTEM_ERROR       = FIRST_SYSTEM_WINDOW+10;
       
        /**
         * End of types of system windows.
         */
        public static final int LAST_SYSTEM_WINDOW      = 2999;

---------------------------------
这个FIRST_SYSTEM_WINDOW的值就是2000。2003和2002的区别就在于2003类型的View比2002类型的还要top，能显示在系统下拉状态栏之上！

    可以看出来，2002的值的含义其实就是2000+2。数值2000的含义就是系统级窗口，2002和2003的区别就是 2003 比 2002还要更上一层！比如，type为2003的view，能显示在手机下拉状态栏之上！

而关于flags等其他的属性请参考SDK文档

Android悬浮窗体
http://www.xsmile.net/?p=396
Android中悬浮窗口的实现原理和示例代码
http://www.xsmile.net/?p=404

Android中可自由移动悬浮窗口的Demo
http://www.xsmile.net/?p=452
前段时间捣鼓出Android悬浮窗口的实现，今天抽空写了一个可自由移动悬浮窗口的Demo。

简要说明如下：

1、通过覆写悬浮View中onTouchEvent方法实现自由移动悬浮窗口。

2、悬浮窗口坐标的移动实际是windowMananager.LayoutParams中x和y的变换，但是要注意设置相应的gravity。

3、用windowManager创建的View，当不需要时，务必记住使用windowManager的removeView方法来移除，请在Activity相关生命周期中自行添加扫尾工作。

4、代码中已经附上详细注释。有关参数具体含义，请自行参考SDK。

===============================

注意Demo中wmParams.format=1的属性（我源码中打了双斜杠），如果启用，图片背景将会透明，效果图如下：


================================

一些说明：

对于种种原因没有查看SDK文档的一些朋友，可能对我源码中wmParams.type=2002这样的语句不太了解其2002的具体意义，给出可读性好点的语句。

 wmParams.type=LayoutParams.TYPE_PHONE; 
        //wmParams.format=PixelFormat.RGBA_8888;   //设置图片格式，效果为背景透明
        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;
        */

附Demo源码：

Android中悬浮窗口
http://www.cnblogs.com/GnagWang/archive/2011/02/06/1949569.html