The example of this paper describes the Android touch screen test code in detail, which can handle the click, move, leave and other events of the touch screen, which has a good reference value for Android beginners.

The specific function code is as follows:

package com.test;
import android.app.Activity;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.widget.AbsoluteLayout;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;
public class TouchActivity extends Activity {
  /* The statement ImageView variable */
  private ImageView mImageView01;
  /* Declare related variables to store image width and height , use */
  private int intWidth, intHeight, intDefaultX, intDefaultY;
  private float mX, mY;
  /* Declares the resolution variable for the storage screen  */
  private int intScreenX, intScreenY;
  public void onCreate(Bundle savedInstanceState)
  {
   super.onCreate(savedInstanceState);
   setContentView(R.layout.main);

   /*  Get the screen object  */
   DisplayMetrics dm = new DisplayMetrics();
   getWindowManager().getDefaultDisplay().getMetrics(dm);

   /*  Gets the screen resolution pixel  */
   intScreenX = dm.widthPixels;
   intScreenY = dm.heightPixels;

   /*  Set the width and height of the image  */
   intWidth = 100;
   intHeight = 100;
   /* through findViewById Constructor creation ImageView object */
   mImageView01 =(ImageView) findViewById(R.id.myImageView1);
   /* From the picture Drawable Assigned to ImageView To render */
   mImageView01.setImageResource(R.drawable.baby);

   /*  The initialization button is centered  */
   RestoreButton();

   /*  When you click ImageView , restore the initial position  */
   mImageView01.setOnClickListener(new Button.OnClickListener()
   {
    @Override
    public void onClick(View v)
    {
     RestoreButton();
    }
   });
  }

  /* Override touch events */
  public boolean onTouchEvent(MotionEvent event)
  {
   /* Get the position of the finger on the screen */
   float x = event.getX();
   float y = event.getY();

   try
   {
    /* Handling of touch events */
    switch (event.getAction())
    {
     /* Click on the screen */
     case MotionEvent.ACTION_DOWN:
      picMove(x, y);
       break;
     /* Mobile location */
     case MotionEvent.ACTION_MOVE:
      picMove(x, y);
       break;
     /* Leave the screen */
     case MotionEvent.ACTION_UP:
      picMove(x, y);
       break;
    }
   }catch(Exception e)
    {
     e.printStackTrace();
    }
   return true;
  }
  /* How to move an image */
  private void picMove(float x, float y)
  {
   /* The default position of the image relative to the pointer is tweaked */
   mX=x-(intWidth/2);
   mY=y-(intHeight/2);

   /* Prevent images from exceeding the screen related processing */
   /* Prevent the screen from overrunning the screen to the right */
   if((mX+intWidth)>intScreenX)
   {
    mX = intScreenX-intWidth;
   }
   /* Prevent the screen from going left over the screen */
   else if(mX<0)
   {
    mX = 0;
   }
   /* Prevent the screen from falling over the screen */
   else if ((mY+intHeight)>intScreenY)
   {
    mY=intScreenY-intHeight;
   }
   /* Prevent the screen from going up over the screen */
   else if (mY<0)
   {
    mY = 0;
   }
   /* through log  To see where the picture is */
   Log.i("jay", Float.toString(mX)+","+Float.toString(mY));
   /*  In order to setLayoutParams Method, rearrange Layout On the location of the  */
   mImageView01.setLayoutParams
   (
    new AbsoluteLayout.LayoutParams
    (intWidth,intHeight,(int) mX,(int)mY)
   );
  }

  /*  reduction ImageView Event handling for location  */
  public void RestoreButton()
  {
   intDefaultX = ((intScreenX-intWidth)/2);
   intDefaultY = ((intScreenY-intHeight)/2);
   /*Toast Reduction position coordinates */
   mMakeTextToast
   (
    "("+
    Integer.toString(intDefaultX)+
    ","+
    Integer.toString(intDefaultY)+")",true
   );

   /*  In order to setLayoutParams Method, rearrange Layout On the location of the  */
   mImageView01.setLayoutParams
   (
    new AbsoluteLayout.LayoutParams
    (intWidth,intHeight,intDefaultX,intDefaultY)
   );
  }

  /* The custom 1 A way to send a message */
  public void mMakeTextToast(String str, boolean isLong)
  {
   if(isLong==true)
   {
    Toast.makeText(TouchActivity.this, str, Toast.LENGTH_LONG).show();
   }
   else
   {
    Toast.makeText(TouchActivity.this, str, Toast.LENGTH_SHORT).show();
   }
  }
}

The reader can also improve the response handling functions of various events on the basis of this example to make its functions more rich.