Android通过手势实现的缩放处理

01 import android.app.Activity;
02 import android.content.Context;
03 import android.graphics.Canvas;
04 import android.graphics.Color;
05 import android.graphics.Paint;
06 import android.os.Bundle;
07 import android.util.DisplayMetrics;
08 import android.view.MotionEvent;
09 import android.view.View;
10  
11 /**
12  * ...
13  * 
14  * @author vlinux
15  * 
16  */
17 public class MultiTouchTestActivity extends Activity {
18     /** Called when the activity is first created. */
19     @Override
20     public void onCreate(Bundle savedInstanceState) {
21         super.onCreate(savedInstanceState);
22         // setContentView(R.layout.main);
23         View view = new MultiTouchView(this);
24         setContentView(view);
25     }
26  
27     class MultiTouchView extends View {
28  
29         private float x1;
30         private float y1;
31         private float x2;
32         private float y2;
33  
34         public MultiTouchView(Context context) {
35             super(context);
36             // TODO Auto-generated constructor stub
37         }
38  
39         @Override
40         public boolean onTouchEvent(MotionEvent event) {
41             // TODO Auto-generated method stub
42  
43             float size = event.getSize();
44  
45             int szi = (int) size;
46             int dxi = szi >> 12;
47             int dyit = ((1 << 12) - 1);
48             int dyi = szi & dyit;
49  
50             DisplayMetrics metrics = getResources().getDisplayMetrics();