Android--使用Camera拍照

 1     /** 检测设备是否存在Camera硬件 */
 2     private boolean checkCameraHardware(Context context) {
 3         if (context.getPackageManager().hasSystemFeature(
 4                 PackageManager.FEATURE_CAMERA)) {
 5             // 存在
 6             return true;
 7         } else {
 8             // 不存在
 9             return false;
10         }
11     }

 1 package cn.bgxt.camerapicturedemo;
 2 
 3 import java.io.IOException;
 4 import android.content.Context;
 5 import android.hardware.Camera;
 6 import android.util.Log;
 7 import android.view.SurfaceHolder;
 8 import android.view.SurfaceView;
 9 
10 /**
11  * 定义一个预览类
12  */
13 public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
14     private static final String TAG = "main";
15     private SurfaceHolder mHolder;
16     private Camera mCamera;
17 
18     public CameraPreview(Context context, Camera camera) {
19         super(context);
20         mCamera = camera;
21 
22         // 通过SurfaceView获得SurfaceHolder
23         mHolder = getHolder();
24         // 为SurfaceHolder指定回调
25         mHolder.addCallback(this);
26         // 设置Surface不维护自己的缓冲区，而是等待屏幕的渲染引擎将内容推送到界面 在Android3.0之后弃用
27         mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
28     }
29 
30     public void surfaceCreated(SurfaceHolder holder) {
31         // 当Surface被创建之后，开始Camera的预览
32         try {
33             mCamera.setPreviewDisplay(holder);
34             mCamera.startPreview();
35         } catch (IOException e) {
36             Log.d(TAG, "预览失败");
37         }
38     }
39 
40     public void surfaceDestroyed(SurfaceHolder holder) {
41         
42     }
43 
44     public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
45         // Surface发生改变的时候将被调用，第一次显示到界面的时候也会被调用
46         if (mHolder.getSurface() == null){
47           // 如果Surface为空，不继续操作
48           return;
49         }
50 
51         // 停止Camera的预览
52         try {
53             mCamera.stopPreview();
54         } catch (Exception e){
55             Log.d(TAG, "当Surface改变后，停止预览出错");
56         }
57 
58         // 在预览前可以指定Camera的各项参数
59 
60         // 重新开始预览
61         try {
62             mCamera.setPreviewDisplay(mHolder);
63             mCamera.startPreview();
64 
65         } catch (Exception e){
66             Log.d(TAG, "预览Camera出错");
67         }
68     }
69 }

  1 package cn.bgxt.camerapicturedemo;
  2 
  3 import java.io.File;
  4 import java.io.FileOutputStream;
  5 
  6 import android.os.Bundle;
  7 import android.util.Log;
  8 import android.view.View;
  9 import android.widget.Button;
 10 import android.widget.FrameLayout;
 11 import android.app.Activity;
 12 import android.content.Context;
 13 import android.content.pm.PackageManager;
 14 import android.hardware.Camera;
 15 import android.hardware.Camera.AutoFocusCallback;
 16 import android.hardware.Camera.PictureCallback;
 17 
 18 public class MainActivity extends Activity {
 19     protected static final String TAG = "main";
 20     private Camera mCamera;
 21     private CameraPreview mPreview;
 22 
 23     @Override
 24     protected void onCreate(Bundle savedInstanceState) {
 25         super.onCreate(savedInstanceState);
 26         setContentView(R.layout.activity_main);
 27 
 28         mCamera = getCameraInstance();
 29 
 30         // 创建预览类，并与Camera关联，最后添加到界面布局中
 31         mPreview = new CameraPreview(this, mCamera);
 32         FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
 33         preview.addView(mPreview);
 34 
 35 
 36         Button captureButton = (Button) findViewById(R.id.button_capture);
 37         captureButton.setOnClickListener(new View.OnClickListener() {
 38             @Override
 39             public void onClick(View v) {
 40                 // 在捕获图片前进行自动对焦
 41                 mCamera.autoFocus(new AutoFocusCallback() {
 42                     
 43                     @Override
 44                     public void onAutoFocus(boolean success, Camera camera) {
 45                         // 从Camera捕获图片
 46                         mCamera.takePicture(null, null, mPicture);
 47                     }
 48                 });                
 49             }
 50         });
 51     }
 52 
 53     /** 检测设备是否存在Camera硬件 */
 54     private boolean checkCameraHardware(Context context) {
 55         if (context.getPackageManager().hasSystemFeature(
 56                 PackageManager.FEATURE_CAMERA)) {
 57             // 存在
 58             return true;
 59         } else {
 60             // 不存在
 61             return false;
 62         }
 63     }
 64 
 65     /** 打开一个Camera */
 66     public static Camera getCameraInstance() {
 67         Camera c = null;
 68         try {
 69             c = Camera.open(); 
 70         } catch (Exception e) {
 71             Log.d(TAG, "打开Camera失败失败");
 72         }
 73         return c; 
 74     }
 75 
 76     private PictureCallback mPicture = new PictureCallback() {
 77 
 78         @Override
 79         public void onPictureTaken(byte[] data, Camera camera) {
 80             // 获取Jpeg图片，并保存在sd卡上
 81             File pictureFile = new File("/sdcard/" + System.currentTimeMillis()
 82                     + ".jpg");
 83             try {
 84                 FileOutputStream fos = new FileOutputStream(pictureFile);
 85                 fos.write(data);
 86                 fos.close();
 87             } catch (Exception e) {
 88                 Log.d(TAG, "保存图片失败");
 89             }
 90         }
 91     };
 92 
 93     @Override
 94     protected void onDestroy() {
 95         // 回收Camera资源
 96         if(mCamera!=null){
 97             mCamera.stopPreview();
 98             mCamera.release();
 99             mCamera=null;
100         }
101         super.onDestroy();
102     }
103     
104 }