OnScreen JoyStick运动的麻烦

Question

麻烦：
当我移动JoyStick时，我的ImageView也会移动（OK） 但是当我停止移动JoyStick时，我的ImageView不会移动 请帮帮我，我没有任何想法。

Look at my result (click here)

我的代码：

（GameScreen.java）

package com.twikoffin.windhack;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.TextView;

import com.harrysoft.joystickview.JoystickView;

public class GameScreen extends AppCompatActivity implements JoystickView.JoystickListener{
    RelativeLayout layout_joystick;
    ImageView playerImage;
    TextView textView1, textView2, textView3, textView4, textView5;
    float x = 0;
    float y = 0;
    float rotation = 0;
    boolean isTouched = false;
    private JoystickView joystick;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.gamescreen_activity);
        joystick = findViewById(R.id.my_joystick);
        joystick.setJoystickListener(this);
        playerImage = findViewById(R.id.player1);



    }
    @Override
    public void onJoystickMoved(float xValue, float yValue, int id) {

        y =  yValue;
        x =  xValue;
        playerImage.setX(x+playerImage.getX());
        playerImage.setY(y+playerImage.getY());


    }
}