仿ios touch按钮创建可随意拖动的悬浮按钮

WindowManager mWindowManager;
WindowManager.LayoutParams wmParams;
LinearLayout mFloatLayout;
ImageView mFloatView;

private void createFloatView() {
//获取LayoutParams对象
wmParams = new WindowManager.LayoutParams();

//获取的是LocalWindowManager对象
mWindowManager = this.getWindowManager();
Log.i(TAG, "mWindowManager1--->" + this.getWindowManager());
//mWindowManager = getWindow().getWindowManager();
Log.i(TAG, "mWindowManager2--->" + getWindow().getWindowManager());

//获取的是CompatModeWrapper对象
//mWindowManager = (WindowManager) getApplication().getSystemService(Context.WINDOW_SERVICE);
Log.i(TAG, "mWindowManager3--->" + mWindowManager);
wmParams.type = WindowManager.LayoutParams.TYPE_SYSTEM_ALERT;
wmParams.format = PixelFormat.RGBA_8888;
wmParams.flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE;
wmParams.gravity = Gravity.LEFT | Gravity.TOP;
wmParams.x = 0;
wmParams.y = 100;
wmParams.width = WindowManager.LayoutParams.WRAP_CONTENT;
wmParams.height = WindowManager.LayoutParams.WRAP_CONTENT;

LayoutInflater inflater = this.getLayoutInflater();//LayoutInflater.from(getApplication());

mFloatLayout = (LinearLayout) inflater.inflate(R.layout.home_easy_touch_view, null);
mWindowManager.addView(mFloatLayout, wmParams);
//setContentView(R.layout.main);
mFloatView = (ImageView) mFloatLayout.findViewById(R.id.easy_touch_view_imageview);

Log.i(TAG, "mFloatView" + mFloatView);
Log.i(TAG, "mFloatView--parent-->" + mFloatView.getParent());
Log.i(TAG, "mFloatView--parent--parent-->" + mFloatView.getParent().getParent());
//绑定触摸移动监听
mFloatView.setOnTouchListener(mTouchListener);

}

private View.OnTouchListener mTouchListener = new View.OnTouchListener() {
float lastX, lastY;
int paramX, paramY;
private int mOldOffsetX;
private int mOldOffsetY;
private int mTag = 0;

public boolean onTouch(View v, MotionEvent event) {
final int action = event.getAction();

float x = event.getRawX();
float y = event.getRawY();

if (mTag == 0) {
mOldOffsetX = wmParams.x; // ƫ����
mOldOffsetY = wmParams.y; // ƫ����
}

switch (action) {

case MotionEvent.ACTION_MOVE:
wmParams.x = (int) event.getRawX() - mFloatLayout.getWidth() / 2;
//25为状态栏高度
wmParams.y = (int) event.getRawY() - mFloatLayout.getHeight() / 2 - 40;
mWindowManager.updateViewLayout(mFloatLayout, wmParams);
mTag = 1;
break;

case MotionEvent.ACTION_UP:
motionActionUpEvent(x, y);
break;

default:
break;
}

return true;
}

private void motionActionUpEvent(float x, float y) {
int newOffsetX = wmParams.x;
int newOffsetY = wmParams.y;
if (Math.abs(mOldOffsetX - newOffsetX) > 50 || Math.abs(mOldOffsetY - newOffsetY) > 50) {
mTag = 0;
} else {
try {
Intent intentUhome = new Intent();
PackageManager packageManager = getPackageManager();
intentUhome = packageManager.getLaunchIntentForPackage(SpeechUtil.AVS_PROCESS_NAME);
intentUhome.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED | Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intentUhome);

} catch (Exception ex) {
ex.toString();
}
}
}

};

home_easy_touch_view.xml代码：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@android:color/transparent"
android:orientation="vertical" >

<ImageView
android:id="@+id/easy_touch_view_imageview"
android:layout_width="200px"
android:layout_height="250px"
android:background="@drawable/icon_avs" />

</LinearLayout>

往android6.0的系统上运行时，会崩溃，抛出permission denied for this window type异常。但在AndroidMenafest.xml中已经添加了SYSTEM_ALERT_WINDOW的权限，
解决方法：
将wmParams.type = WindowManager.LayoutParams.TYPE_SYSTEM_ALERT;改成

wmParams.type = WindowManager.LayoutParams.TYPE_TOAST;即可。