任何人都可以帮我修复这个奇怪的Android bug吗？

Question

我遇到了一个奇怪的错误，当这个代码作为一个应用程序运行时，灰色框被拖放到左边一点点，我再也不能将它拖到屏幕的左边四分之一。

这是我的代码......

import android.graphics.Point;
import android.os.Bundle;
import android.app.Activity;
import android.view.Display;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.Toast;

public class drag_activity extends Activity implements View.OnTouchListener{
 private ViewGroup viewGroup;
 private ImageView imageBackground;
 private int xPos;
 private int yPos;
 int width;
 int height;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.activity_drag_activity);
     Display display = getWindowManager().getDefaultDisplay();
     Point size = new Point();
     display.getSize(size);
     viewGroup = (ViewGroup) findViewById(R.id.marco);
     imageBackground = (ImageView)findViewById(R.id.imageView);
     findViewById(R.id.imageView3).setOnTouchListener(this);
     findViewById(R.id.imageView4).setOnTouchListener(this);
     findViewById(R.id.imageView5).setOnTouchListener(this);
     findViewById(R.id.imageView6).setOnTouchListener(this);
     findViewById(R.id.imageView7).setOnTouchListener(this);
     findViewById(R.id.imageView8).setOnTouchListener(this);
     findViewById(R.id.imageView10).setOnTouchListener(this);
     findViewById(R.id.imageView11).setOnTouchListener(this);
     findViewById(R.id.imageView12).setOnTouchListener(this);
     findViewById(R.id.imageView13).setOnTouchListener(this);
     width = size.x;
     height = size.y;
     View.OnTouchListener clickListener = new View.OnTouchListener() {
         @Override
         public boolean onTouch(View view, MotionEvent event) {
             Toast.makeText(drag_activity.this, "Max Walls reached!", Toast.LENGTH_LONG).show();
             return false;
         }
     };
     imageBackground.setOnTouchListener(clickListener);
 }
 public boolean onTouch(View view, MotionEvent event) {
  final int X = (int) event.getRawX();
  final int Y = (int) event.getRawY();
  switch (event.getAction() & MotionEvent.ACTION_MASK) {
     case MotionEvent.ACTION_DOWN:
         RelativeLayout.LayoutParams Params = (RelativeLayout.LayoutParams) view.getLayoutParams();
         xPos = X - Params.leftMargin;
         yPos = Y - Params.topMargin;
         break;
     case MotionEvent.ACTION_UP:
         Toast.makeText(this,""+view.getY(),Toast.LENGTH_SHORT).show();
         if(view.getY() > height-(120 + imageBackground.getHeight())){
             view.setY(height-(20+imageBackground.getHeight()));
             view.setX((width/2)-(imageBackground.getWidth()/2));
         }
         Toast.makeText(this,""+view.getY(),Toast.LENGTH_SHORT).show();
         break;
     case MotionEvent.ACTION_POINTER_DOWN:
         break;
      case MotionEvent.ACTION_POINTER_UP:
          break;
      case MotionEvent.ACTION_MOVE:
          RelativeLayout.LayoutParams layoutParams = (RelativeLayout.LayoutParams) view.getLayoutParams();
          layoutParams.leftMargin = X - xPos;
          layoutParams.topMargin = Y - yPos;
          layoutParams.rightMargin = -50;
          layoutParams.bottomMargin = -50;
          view.setLayoutParams(layoutParams);
          break;
      }
      viewGroup.invalidate();
      return true;
  }}

任何解释或建议都会有所帮助，谢谢！

这是一张图片：