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