Android 悬浮窗口

public class MainActivity extends Activity {
    private WindowManager mWindowManager;
    private WindowManager.LayoutParams mLayout;
    private DesktopLayout mDesktopLayout;
    private long startTime;
    // 声明屏幕的宽高
    float x, y;
    int top;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);        
        createWindowManager();
        createDesktopLayout();
        Button btn = (Button) findViewById(R.id.btn);
        btn.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                showDesk();
            }
        });
    }
    /**
     * 创建悬浮窗体
     */
    private void createDesktopLayout() {
        mDesktopLayout = new DesktopLayout(this);
        mDesktopLayout.setOnTouchListener(new OnTouchListener() {
            float mTouchStartX;
            float mTouchStartY;

            @Override
            public boolean onTouch(View v, 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() - top; // 25是系统状态栏的高度
                Log.i("startP", "startX" + mTouchStartX + "====startY"
                        + mTouchStartY);
                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);
                    long end = System.currentTimeMillis() - startTime;
                    // 双击的间隔在 300ms以下
                    if (end < 300) {
                        closeDesk();
                    }
                    startTime = System.currentTimeMillis();
                    break;
                case MotionEvent.ACTION_MOVE:
                    // 更新浮动窗口位置参数
                    mLayout.x = (int) (x - mTouchStartX);
                    mLayout.y = (int) (y - mTouchStartY);
                    mWindowManager.updateViewLayout(v, mLayout);
                    break;
                case MotionEvent.ACTION_UP:

                    // 更新浮动窗口位置参数
                    mLayout.x = (int) (x - mTouchStartX);
                    mLayout.y = (int) (y - mTouchStartY);
                    mWindowManager.updateViewLayout(v, mLayout);

                    // 可以在此记录最后一次的位置

                    mTouchStartX = mTouchStartY = 0;
                    break;
                }
                return true;
            }
        });
    }

    @Override
    public void onWindowFocusChanged(boolean hasFocus) {
        super.onWindowFocusChanged(hasFocus);
        Rect rect = new Rect();
        // /取得整个视图部分,注意，如果你要设置标题样式，这个必须出现在标题样式之后，否则会出错
        getWindow().getDecorView().getWindowVisibleDisplayFrame(rect);
        top = rect.top;//状态栏的高度，所以rect.height,rect.width分别是系统的高度的宽度

        Log.i("top",""+top);
    }

    /**
     * 显示DesktopLayout
     */
    private void showDesk() {
        mWindowManager.addView(mDesktopLayout, mLayout);
        finish();
    }

    /**
     * 关闭DesktopLayout
     */
    private void closeDesk() {
        mWindowManager.removeView(mDesktopLayout);
        finish();
    }

    /**
     * 设置WindowManager
     */
    private void createWindowManager() {
        // 取得系统窗体
        mWindowManager = (WindowManager) getApplicationContext()
                .getSystemService("window");

        // 窗体的布局样式
        mLayout = new WindowManager.LayoutParams();

        // 设置窗体显示类型――TYPE_SYSTEM_ALERT(系统提示)
        mLayout.type = WindowManager.LayoutParams.TYPE_SYSTEM_ALERT;

        // 设置窗体焦点及触摸：
        // FLAG_NOT_FOCUSABLE(不能获得按键输入焦点)
        mLayout.flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE;

        // 设置显示的模式
        mLayout.format = PixelFormat.RGBA_8888;

        // 设置对齐的方法
        mLayout.gravity = Gravity.TOP | Gravity.LEFT;

        // 设置窗体宽度和高度
        mLayout.width = WindowManager.LayoutParams.WRAP_CONTENT;
        mLayout.height = WindowManager.LayoutParams.WRAP_CONTENT;

    }

}

public class DesktopLayout extends LinearLayout {

    public DesktopLayout(Context context) {
        super(context);
        setOrientation(LinearLayout.VERTICAL);// 水平排列
        

        //设置宽高
        this.setLayoutParams( new LayoutParams(LayoutParams.WRAP_CONTENT,
                LayoutParams.WRAP_CONTENT));
        
        View view = LayoutInflater.from(context).inflate(  
                R.layout.desklayout, null); 
        this.addView(view);
    }

}

别忘了在AndroidManifest.xml中加入如下的权限：

public class DesktopLayout extends LinearLayout {

    public DesktopLayout(Context context) {
        super(context);
        setOrientation(LinearLayout.VERTICAL);// 水平排列
        

        //设置宽高
        this.setLayoutParams( new LayoutParams(LayoutParams.WRAP_CONTENT,
                LayoutParams.WRAP_CONTENT));
        
        View view = LayoutInflater.from(context).inflate(  
                R.layout.desklayout, null); 
        this.addView(view);
    }

}