Android 照相机的实例应用

public class MyCameraDemo extends Activity { 
  private SurfaceView surface = null ; 
  private Button but = null ; 
  private SurfaceHolder holder = null ; 
  private Camera cam = null ; 
  private boolean previewRunning = true ; 
  @Override 
  public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    super.setContentView(R.layout.main); 
    this.but = (Button) super.findViewById(R.id.but) ; 
    this.surface = (SurfaceView) super.findViewById(R.id.surface) ; 
     
    this.holder = this.surface.getHolder() ; 
    this.holder.addCallback(new MySurfaceViewCallback()) ; 
    //设置缓冲类型 
    this.holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS) ; 
    //设置分辨率 
    this.holder.setFixedSize(600, 350); 
     
    this.but.setOnClickListener(new OnClickListenerImpl()) ; 
  } 
  private class OnClickListenerImpl implements OnClickListener { 
 
    @Override 
    public void onClick(View v) { 
      if(MyCameraDemo.this.cam != null) { 
        //自动对焦 
        MyCameraDemo.this.cam.autoFocus(new AutoFocusCallbackImpl()) ; 
      } 
    } 
     
  } 
   
  private class MySurfaceViewCallback implements SurfaceHolder.Callback { 
 
    //当预览界面格式大小改变时，调用 
    public void surfaceChanged(SurfaceHolder holder, int format, int width, 
        int height) { 
       
    } 
 
    //初次实例化界面调用 
    public void surfaceCreated(SurfaceHolder holder) { 
      MyCameraDemo.this.cam = Camera.open(0) ;  // 取得第一个摄像头 
      //窗口服务 
      WindowManager manager = (WindowManager) MyCameraDemo.this 
          .getSystemService(Context.WINDOW_SERVICE); 
      //取得display显示对象 
      Display display = manager.getDefaultDisplay() ; 
      //照相机参数 
      Parameters param = MyCameraDemo.this.cam.getParameters() ; 
      //将照相机预览大小设置为display大小 
      param.setPreviewSize(display.getWidth(), display.getHeight()) ; 
      param.setPreviewFrameRate(5) ; // 一秒5帧 
      param.setPictureFormat(PixelFormat.JPEG) ; // 图片形式 
      param.set("jpen-quality", 80) ;//图片质量，最高100 
      MyCameraDemo.this.cam.setParameters(param) ; 
      try { 
        MyCameraDemo.this.cam.setPreviewDisplay(MyCameraDemo.this.holder) ; 
      } catch (IOException e) { 
      } 
      MyCameraDemo.this.cam.startPreview() ; // 进行预览 
      MyCameraDemo.this.previewRunning = true ;  // 已经开始预览 
    } 
 
    @Override 
    public void surfaceDestroyed(SurfaceHolder holder) { 
      if(MyCameraDemo.this.cam != null) { 
        if(MyCameraDemo.this.previewRunning) { 
          MyCameraDemo.this.cam.stopPreview() ;  // 停止预览 
          MyCameraDemo.this.previewRunning = false ; 
        } 
        MyCameraDemo.this.cam.release() ; 
      } 
    } 
     
  } 
   
  private class AutoFocusCallbackImpl implements AutoFocusCallback { 
 
    @Override 
    public void onAutoFocus(boolean success, Camera camera) { 
      if(success) {  // 成功 
        MyCameraDemo.this.cam.takePicture(sc, pc, jpgcall) ; 
      } 
    } 
     
  } 
   
  private PictureCallback jpgcall = new PictureCallback() { 
 
    @Override 
    public void onPictureTaken(byte[] data, Camera camera) {  // 保存图片的操作 
      Bitmap bmp = BitmapFactory.decodeByteArray(data, 0, data.length); 
      String fileName = Environment.getExternalStorageDirectory() 
          .toString() 
          + File.separator 
          + "mldnphoto" 
          + File.separator 
          + "MLDN_" + System.currentTimeMillis() + ".jpg"; 
      File file = new File(fileName) ; 
      if (!file.getParentFile().exists()) { 
        file.getParentFile().mkdirs() ; // 创建文件夹 
      } 
      try { 
        BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(file)) ; 
        bmp.compress(Bitmap.CompressFormat.JPEG, 80, bos) ; // 向缓冲区之中压缩图片 
        bos.flush() ; 
        bos.close() ; 
        Toast.makeText(MyCameraDemo.this, 
            "拍照成功，照片已保存在" + fileName + "文件之中！", Toast.LENGTH_SHORT) 
            .show(); 
      } catch (Exception e) { 
        Toast.makeText(MyCameraDemo.this, 
            "拍照失败！", Toast.LENGTH_SHORT) 
            .show(); 
      } 
      MyCameraDemo.this.cam.stopPreview() ; 
      MyCameraDemo.this.cam.startPreview() ; 
    } 
     
  } ; 
   
  private ShutterCallback sc = new ShutterCallback(){ 
    @Override 
    public void onShutter() { 
      // 按下快门之后进行的操作 
    } 
  } ; 
  private PictureCallback pc = new PictureCallback() { 
 
    @Override 
    public void onPictureTaken(byte[] data, Camera camera) { 
       
    } 
     
  } ; 
} 

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout  
  xmlns:android="http://schemas.android.com/apk/res/android" 
  android:orientation="vertical"  
  android:layout_width="fill_parent" 
  android:layout_height="fill_parent"> 
  <Button 
    android:id="@+id/but"  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content"  
    android:text="照相" /> 
  <SurfaceView 
    android:id="@+id/surface" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" />  
</LinearLayout>