Android 照相机的实例应用

Android 照相机的实例应用

关键技术：

SurfaceHolder.Callback

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) { 

    } 

  } ;
}

 主布局函数

<?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>

以上就是Android 相机的使用方法，如有疑问请留言或者到本站社区交流讨论，感谢阅读，希望能帮助到大家，谢谢大家对本站的支持！