Android 图片放大缩小

Android 图片放大缩小

1. package com.wansha;  
2.   
3. import android.app.Activity;  
4. import android.app.AlertDialog;  
5. import android.content.DialogInterface;  
6. import android.graphics.Bitmap;  
7. import android.graphics.BitmapFactory;  
8. import android.graphics.Matrix;  
9. import android.os.Bundle;  
10. import android.util.DisplayMetrics;  
11. import android.util.Log;  
12. import android.view.KeyEvent;  
13. import android.view.View;  
14. import android.view.View.OnClickListener;  
15. import android.widget.Button;  
16. import android.widget.ImageView;  
17. import android.widget.RelativeLayout;  
18.   
19. public class Activity31 extends Activity {  
20.     private RelativeLayout layout;  
21.     private Button big;  
22.     private Button small;  
23.     private ImageView bg;  
24.     private Bitmap map;  
25.     private float scaleH = 1;  
26.     private float scaleW = 1;  
27.     private int id;  
28.     private DisplayMetrics metrics;  
29.     @Override  
30.     public void onCreate(Bundle savedInstanceState) {  
31.         super.onCreate(savedInstanceState);  
32.         setContentView(R.layout.main);  
33.         this.layout = (RelativeLayout)this.findViewById(R.id.la);  
34.         this.big = (Button)this.findViewById(R.id.big);  
35.         this.small = (Button)this.findViewById(R.id.small);  
36. //        this.image2 = (ImageView)this.findViewById(R.id.image1);   
37. //        this.image2.setImageResource(R.drawable.left);   
38.         this.bg = (ImageView)this.findViewById(R.id.bg);  
39. //        this.bg.setImageResource(R.drawable.tttt);   
40.           
41.         this.map = BitmapFactory.decodeResource(getResources(), R.drawable.tttt);  
42.         Log.d("mydebug", "imageheigh---->" + map.getWidth() + "imagewidth------->" + map.getHeight());  
43.           
44.         metrics = new DisplayMetrics();  
45.         getWindowManager().getDefaultDisplay().getMetrics(metrics);  
46.           
47. //        Bitmap bm = Bitmap.createBitmap(map, 0, 0, 100, 100);   
48. //        this.bg.setImageBitmap(bm);   
49.         Log.d("mydebug", "screen_width--------->" + metrics.widthPixels + "screen_height----------->" + metrics.heightPixels);  
50.   
51.         this.big.setOnClickListener(new OnClickListener() {  
52.               
53.             @Override  
54.             public void onClick(View v) {  
55.                 float scale = 1.25f;  
56.                 Matrix matrix = new Matrix();  
57.                 scaleW = scaleW * scale;  
58.                 scaleH = scaleH * scale;  
59.                 if(scaleH*map.getHeight() >= metrics.heightPixels || scaleW*map.getWidth() >= metrics.widthPixels){  
60.                     big.setEnabled(false);  
61.                     return;  
62.                 }  
63.                 if(id == 0){  
64.                     layout.removeView(bg);  
65.                 }else{  
66.                     layout.removeView((ImageView)findViewById(id));  
67.                 }  
68.                 matrix.postScale(scaleW, scaleH);  
69.                 Bitmap bitmap = Bitmap.createBitmap(map, 0, 0, map.getWidth(), map.getHeight(), matrix, true);  
70.                 bg.setImageBitmap(bitmap);  
71.                 ImageView image = new ImageView(Activity31.this);  
72.                 image.setId(++id);  
73.                 image.setImageBitmap(bitmap);  
74.                 layout.addView(image);  
75.                 setContentView(layout);  
76.                 System.out.println("bit---------->" + scaleH*scale*map.getHeight() + "    :      " + scaleW*scale*map.getWidth());  
77.                 if(scaleH*scale*map.getHeight() >= metrics.heightPixels || scaleW*scale*map.getWidth() >= metrics.widthPixels){  
78.                     big.setEnabled(false);  
79.                 }else{  
80.                     big.setEnabled(true);  
81.                 }  
82.                 small.setEnabled(true);  
83.             }  
84.         });  
85.         this.small.setOnClickListener(new OnClickListener() {  
86.               
87.             @Override  
88.             public void onClick(View v) {  
89.                 if(id == 0){  
90.                     layout.removeView(bg);  
91.                 }else{  
92.                     layout.removeView((ImageView)findViewById(id));  
93.                 }  
94.                 float scale = 0.8f;  
95.                 Matrix matrix = new Matrix();  
96.                 scaleW = scaleW * scale;  
97.                 scaleH = scaleH * scale;  
98.                 matrix.postScale(scaleW, scaleH);  
99.                 Bitmap bitmap = Bitmap.createBitmap(map, 0, 0, map.getWidth(), map.getHeight(), matrix, true);  
100.                 bg.setImageBitmap(bitmap);  
101.                 ImageView image = new ImageView(Activity31.this);  
102.                 image.setId(++id);  
103.                 image.setImageBitmap(bitmap);  
104.                 layout.addView(image);  
105.                 setContentView(layout);  
106.                 if(scaleH*scale <=  0.4){  
107.                     small.setEnabled(false);  
108.                 }else{  
109.                     big.setEnabled(true);  
110.                 }  
111.                 big.setEnabled(true);  
112.             }  
113.   
114.         });  
115.     }  
116.     @Override  
117.     protected void onSaveInstanceState(Bundle outState) {  
118.         // TODO Auto-generated method stub   
119.         super.onSaveInstanceState(outState);  
120.     }  
121.     @Override  
122.     public boolean onKeyDown(int keyCode, KeyEvent event) {  
123.         System.out.println("keycode--------->" + keyCode);  
124.         if(keyCode == KeyEvent.KEYCODE_BACK){  
125.             new AlertDialog.Builder(this).setTitle("退出").setMessage("确定要退出吗？").setPositiveButton("确定", new DialogInterface.OnClickListener() {  
126.                   
127.                 @Override  
128.                 public void onClick(DialogInterface dialog, int which) {  
129.                     finish();  
130.                     android.os.Process.killProcess(android.os.Process.myPid());  
131.                 }  
132.             }).setNegativeButton("取消", new DialogInterface.OnClickListener() {  
133.                   
134.                 @Override  
135.                 public void onClick(DialogInterface dialog, int which) {  
136.                       
137.                 }  
138.             }).show();  
139.               
140.         }  
141.         return super.onKeyDown(keyCode, event);  
142.     }  
143. }