模拟物理按键；获取当前显示的Activity名

//////////模拟按键方法

   private void sendKeyCode(final int keyCode){
        new Thread(){
            public void run(){
                try {
                    Instrumentation inst = new Instrumentation();
                    inst.sendKeyDownUpSync(keyCode);

/////////以下方法在4.0或是3.0之前可以用

//                  KeyEvent k = new KeyEvent(KeyEvent.ACTION_DOWN, keyCode);
//                  (IWindowManager.Stub.asInterface(ServiceManager.getService("window"))).injectKeyEvent(k, true);

                }catch(Exception e){
                  e.printStackTrace();
                }
            }
        }.start();
    }

//////////调用如，模拟返回键

 sendKeyCode(KeyEvent.KEYCODE_BACK);

--------------------------------------------------------

////获取当前显示的Activity的名字

private String getAct(){
   ActivityManager manager = (ActivityManager) mContext.getSystemService(Context.ACTIVITY_SERVICE);
   String activityName = manager.getRunningTasks(1).get(0).topActivity.getClassName();

      return activityName;
  }