看代码学Android ：如何实现Timer控制照相机？

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1. package com.yarin.android.Examples_07_06;
   
2. 
   
3. import java.util.Timer;
   
4. import java.util.TimerTask;
   
5. 
   
6. import android.app.Activity;
   
7. import android.content.Intent;
   
8. import android.os.Bundle;
   
9. import android.util.Log;
   
10. import android.view.View;
    
11. import android.view.Window;
    
12. 
    
13. public class Activity01 extends Activity
    
14. {
    
15. 
    
16.     /* (non-Javadoc)
    
17.      * @see android.app.Activity#onDestroy()
    
18.      */
    
19.     @Override
    
20.     protected void onDestroy() {
    
21.         if( timer != null){
    
22.             timer.cancel();
    
23.         }
    
24.         // TODO Auto-generated method stub
    
25.         super.onDestroy();
    
26.     }
    
27. 
    
28.     /* (non-Javadoc)
    
29.      * @see android.app.Activity#onResume()
    
30.      */
    
31.     @Override
    
32.     protected void onResume() {        
    
33.         // TODO Auto-generated method stub
    
34.         super.onResume();            
    
35.     }
    
36. 
    
37.     Timer timer = new Timer();
    
38.     
    
39.     /** Called when the activity is first created. */
    
40.     @Override
    
41.     public void onCreate(Bundle savedInstanceState)
    
42.     {
    
43.         super.onCreate(savedInstanceState);
    
44.         requestWindowFeature(Window.FEATURE_NO_TITLE);
    
45.         
    
46.         setContentView(R.layout.main);
    
47.     
    
48.     }
    
49. 
    
50.     public void Test(View view)
    
51.     {        
    
52.         timer.schedule(new TimerTask()
    
53.         {             
    
54.      public void run() {     
    
55.          Log.v("CA", "TimerTask");
    
56.          Intent intent = new Intent();
    
57.          intent.setClass(Activity01.this, CameraActivity.class);
    
58.          Activity01.this.startActivity(intent);    
    
59.      }
    
60.         }, 5000, 2000);
    
61.     }
    
62.     
    
63.     public void Stop(View view)
    
64.     {
    
65.         this.timer.cancel();
    
66.         this.finish();
    
67.     }
    
68. }

1. package com.yarin.android.Examples_07_06;
   
2. 
   
3. import java.io.BufferedOutputStream;
   
4. import java.io.File;
   
5. import java.io.FileOutputStream;
   
6. import java.io.IOException;
   
7. 
   
8. import android.app.Activity;
   
9. import android.content.Context;
   
10. import android.graphics.Bitmap;
    
11. import android.graphics.BitmapFactory;
    
12. import android.graphics.Canvas;
    
13. import android.graphics.PixelFormat;
    
14. import android.hardware.Camera;
    
15. import android.hardware.Camera.PictureCallback;
    
16. import android.os.Bundle;
    
17. //import android.view.KeyEvent;
    
18. import android.util.Log;
    
19. import android.view.SurfaceHolder;
    
20. import android.view.SurfaceView;
    
21. import android.view.Window;
    
22. 
    
23. public class CameraActivity extends Activity {
    
24. 
    
25.     private Preview    mPreview = null;
    
26.     
    
27.     /* (non-Javadoc)
    
28.      * @see android.app.Activity#onPause()
    
29.      */
    
30.     @Override
    
31.     protected void onPause() {
    
32.         Log.v("CA", "onPause");
    
33.         if( mPreview != null ){            
    
34.             mPreview = null;
    
35.         }
    
36.         
    
37.         super.onPause();
    
38.     }
    
39. 
    
40.     /* (non-Javadoc)
    
41.      * @see android.app.Activity#onResume()
    
42.      */
    
43.     @Override
    
44.     protected void onResume() {
    
45.         // Create our Preview view and set it as the content of our activity.
    
46.         Log.v("CA", "onResume");
    
47.         
    
48.         super.onResume();
    
49.     }
    
50.     
    
51. 
    
52.     /** Called when the activity is first created. */
    
53.     @Override
    
54.     public void onCreate(Bundle savedInstanceState)
    
55.     {
    
56.         super.onCreate(savedInstanceState);
    
57.         requestWindowFeature(Window.FEATURE_NO_TITLE);
    
58.         
    
59.         mPreview = new Preview(this);
    
60.         setContentView(mPreview);        
    
61.     }
    
62. 
    
63. 
    
64. 
    
65. /* Preview-显示Preview */
    
66. class Preview extends SurfaceView implements SurfaceHolder.Callback
    
67. {
    
68.     SurfaceHolder mHolder = null;
    
69.     Camera mCamera = null;
    
70.     Bitmap CameraBitmap = null;
    
71.     
    
72.     Preview(Context context)
    
73.     {
    
74.         super(context);
    
75.         mHolder = getHolder();
    
76.         mHolder.addCallback(this);
    
77.         mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    
78.     }
    
79.     
    
80.     public void startCamera() {
    
81.         Log.v("CA", "startCamera");
    
82.         
    
83.         if (mCamera == null) {
    
84.             try {
    
85.                 mCamera = Camera.open();
    
86.                 Log.v("CA", "Camera.open");
    
87.             } catch (Exception e) {
    
88.             }
    
89.             
    
90.         } else {
    
91.             try {
    
92.                 mCamera.reconnect();
    
93.             } catch (IOException e) {
    
94.                 mCamera.release();
    
95.                 mCamera = null;
    
96.             }
    
97.         }
    
98.         
    
99.     }
    
100. 
     
101.     public void stopCamera() {
     
102.         Log.v("CA", "stopCamera");
     
103.         
     
104.         if (mCamera != null) {
     
105.             try {
     
106.                 mCamera.stopPreview();
     
107.             } catch (Exception e) {
     
108.                 // Ignore
     
109.             }
     
110. 
     
111.             try {
     
112.                 mCamera.release();
     
113.                 Log.v("CA", "mCamera.release");
     
114.             } catch (Exception e) {
     
115.                 // Ignore
     
116.             }
     
117. 
     
118.             mCamera = null;
     
119.         }
     
120.     }
     
121. 
     
122.     @Override
     
123.     public void surfaceCreated(SurfaceHolder holder)
     
124.     {
     
125.         Log.v("CA", "surfaceCreated");
     
126.         
     
127.         startCamera();
     
128.         
     
129.         if( mCamera == null ) return;
     
130.         
     
131.         Log.v("CA", "Camera create!");
     
132.         
     
133.         try {
     
134.             mCamera.setPreviewDisplay(holder);
     
135.         } catch (IOException e) {
     
136.             mCamera.release();
     
137.             mCamera = null;
     
138.             e.printStackTrace();
     
139.         }             
     
140.     }
     
141. 
     
142.     @Override
     
143.     public void surfaceDestroyed(SurfaceHolder holder)
     
144.     {
     
145.         Log.v("CA", "surfaceDestroyed");
     
146.         stopCamera();
     
147.     }
     
148.     
     
149.     @Override
     
150.     public void surfaceChanged(SurfaceHolder holder, int format, int w, int h)
     
151.     {
     
152.         Log.v("CA", "surfaceChanged");
     
153.         if( holder.isCreating() && mCamera != null ){
     
154.             
     
155.             if( mCamera != null ){
     
156.              /* 构建Camera.Parameters对相机的参数进行设置 */
     
157.          //Camera.Parameters parameters = mCamera.getParameters();
     
158.          /* 设置拍照的图片格式 */
     
159.          //parameters.setPictureFormat(PixelFormat.JPEG);
     
160.          /* 设置Preview的尺寸 */
     
161.          //parameters.setPreviewSize(320, 480);
     
162.          /* 设置图像分辨率 */
     
163.          //parameters.setPictureSize(320, 480);
     
164.          /* 设置相机采用parameters */
     
165.          //mCamera.setParameters(parameters);
     
166.          /* 开始预览 */
     
167.          mCamera.startPreview();    
     
168.          
     
169.          CameraActivity.this.finish();
     
170.             }
     
171.         }
     
172.     }
     
173.     /* 拍照片 */
     
174.     public void takePicture()
     
175.     {
     
176.       if (mCamera != null)
     
177.       {
     
178.          mCamera.takePicture(null, null, jpegCallback);
     
179.       }
     
180.     }
     
181.     /* 拍照后输出图片 */
     
182.     private PictureCallback jpegCallback = new PictureCallback()
     
183.     {
     
184.       public void onPictureTaken(byte[] _data, Camera _camera)
     
185.       {
     
186.         // TODO Handle JPEG image data
     
187.         CameraBitmap = BitmapFactory.decodeByteArray(_data, 0, _data.length);
     
188.         File myCaptureFile = new File("/sdcard/camera1.jpg");
     
189.         try
     
190.         {
     
191.           BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(myCaptureFile));
     
192.           CameraBitmap.compress(Bitmap.CompressFormat.JPEG, 80, bos);
     
193.           bos.flush();
     
194.           bos.close();
     
195.           /* 将拍到的图片绘制出来 */
     
196.           Canvas canvas= mHolder.lockCanvas();
     
197.           canvas.drawBitmap(CameraBitmap, 0, 0, null);
     
198.           mHolder.unlockCanvasAndPost(canvas);
     
199.           
     
200.         }
     
201.         catch (Exception e)
     
202.         {
     
203.             e.getMessage();
     
204.         }
     
205.       }
     
206.     };
     
207. }
     
208. 
     
209. }