Question

嘿伙计们我正在使用以下代码从我的应用程序访问相机。应用程序能够访问相机我还添加了一个按钮，其onclicklistener添加了这行代码： -

camera.takePicture(mShutterCallback, mPictureCallbackRaw, mPictureCallbackJpeg);

现在我不知道会发生什么但应用程序卡住了我必须强制关闭它然后我甚至无法访问本机相机应用程序。我认为它会在不释放Camera对象的情况下离开应用程序。此外，图像永远不会被保存。

代码： -

SurfaceHolder holder;
SurfaceView  surface;
Camera camera;
Boolean isPreviewRunning, fromOnResume;
//Preview mpreview;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    isPreviewRunning = false;
    fromOnResume = false;
   // requestWindowFeature(Window.FEATURE_NO_TITLE);
    surface = (SurfaceView)findViewById(R.id.surface);
    holder = surface.getHolder();
  holder.addCallback(this);
  holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

  Button btn = (Button)findViewById(R.id.click);
    btn.setOnClickListener(new OnClickListener(){

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            camera.takePicture(mShutterCallback, mPictureCallbackRaw, mPictureCallbackJpeg);
            //onCreate(null);


        }

    });

}


@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
        int height) {
/*  if (isPreviewRunning) {  
          camera.stopPreview();  
         }  */

    Camera.Parameters parameters = camera.getParameters();

    List<Size> sizes = parameters.getSupportedPreviewSizes();
    Size size = sizes.get(0);
    parameters.setPreviewSize(size.width, size.height);

    camera.setParameters(parameters);
     camera.startPreview();  
     isPreviewRunning=true;
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
    // TODO Auto-generated method stub

     camera = Camera.open();

     try {
        camera.setPreviewDisplay(holder);
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();

    }
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
    // TODO Auto-generated method stub

    camera.stopPreview();
    camera.release();
    camera=null;
}

 Camera.PictureCallback mPictureCallbackRaw = new Camera.PictureCallback() {
 public void onPictureTaken(byte[] data, Camera c) {
  Log.e(getClass().getSimpleName(), "PICTURE CALLBACK RAW: " + data);
  camera.startPreview();
 }
 };

 Camera.PictureCallback mPictureCallbackJpeg= new Camera.PictureCallback() {
 public void onPictureTaken(byte[] data, Camera c) {
  Log.e(getClass().getSimpleName(), "PICTURE CALLBACK JPEG: data.length = " + data);

  camera.startPreview();
 }
 };


 Camera.ShutterCallback mShutterCallback = new Camera.ShutterCallback() {
 public void onShutter() {
 Log.e(getClass().getSimpleName(), "SHUTTER CALLBACK");
 }
 };
/*
 *  protected void onRestoreInstanceState(Bundle savedInstanceState)
 {

 super.onRestoreInstanceState(savedInstanceState);
 }
 protected void onResume()
 {

 Log.e(getClass().getSimpleName(), "onResume");
 camera.open();
 fromOnResume=true;
 super.onResume();
 }

 protected void onSaveInstanceState(Bundle outState)
 {
 super.onSaveInstanceState(outState);
 }

 @Override
protected void onPause() {
    // TODO Auto-generated method stub
     camera.release();
    super.onPause();
}


 protected void onStop()
 {
 Log.e(getClass().getSimpleName(), "onStop");
 super.onStop();
 }*/

Answer 1

我知道这不是你问题的答案，但使用相机应用程序会不会更容易？您可以在活动中使用此代码访问它：

@Override
public void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.capture);

    Button capture = (Button) findViewById(R.id.capture_button);
    capture.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            // We use the stock camera app to take a photo
            Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
            intent.putExtra(MediaStore.EXTRA_OUTPUT, getImageUri());
            startActivityForResult(intent, TAKE_PHOTO_CODE);
        }
    });
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);

    if (requestCode == TAKE_PHOTO_CODE && resultCode == RESULT_OK) {
        Uri imagePath = getImageUri();

        doSomething();
    }
}

/**
 * Get the uri of the captured file
 * @return A Uri which path is the path of an image file, stored on the dcim folder
 */
private Uri getImageUri() {
    // Store image in dcim
    File file = new File(Environment.getExternalStorageDirectory() + "/DCIM", CAPTURE_TITLE);
    Uri imgUri = Uri.fromFile(file);

    return imgUri;
}

Answer 2

只是一个建议，在将其上传到服务器之前在jpg上使用EXIF。由于当今智能手机相机的质量，我发现上传图片的速度非常慢。一个简单的解决方案是使用exif读取程序来提取jpeg的缩略图，将所述缩略图保存为新的jpeg，然后上传它。它与原始照片相同但更小（低于100kb ）。我不确定它是否是您想要的图像质量，但如果没有，并且上传大量图片，请使用exif方法。我在python sl4a上编程并使用了EXIF.py，但我确信Java中有类似的东西。

如何捕获图像并将其保存在SD卡中

2 个答案: