8

我正在为我的应用程序开发自定义相机活动。我在这里遵循 Android 开发者网站的说明：http: //developer.android.com/guide/topics/media/camera.html 一切似乎都很好，除了回调函数没有被调用并且图片没有保存. 这是我的代码：

public class CameraActivity extends Activity {
private Camera mCamera;
private CameraPreview mPreview;
private static final String TAG = "CameraActivity";

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.camera);

    // Create an instance of Camera
    mCamera = getCameraInstance();

    // Create our Preview view and set it as the content of our activity.
    mPreview = new CameraPreview(this, mCamera);
    FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
    preview.addView(mPreview);

    Button captureButton = (Button) findViewById(R.id.button_capture);
    captureButton.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            Log.v(TAG, "will now take picture");
            mCamera.takePicture(null, null, mPicture);
            Log.v(TAG, "will now release camera");
            mCamera.release();
            Log.v(TAG, "will now call finish()");
            finish();
        }
    });        
}

private PictureCallback mPicture = new PictureCallback() {

    @Override
    public void onPictureTaken(byte[] data, Camera camera) {
        Log.v(TAG, "Getting output media file");
        File pictureFile = getOutputMediaFile();
        if (pictureFile == null) {
            Log.v(TAG, "Error creating output file");
            return;
        }
        try {
            FileOutputStream fos = new FileOutputStream(pictureFile);
            fos.write(data);
            fos.close();
        } catch (FileNotFoundException e) {
            Log.v(TAG, e.getMessage());
        } catch (IOException e) {
            Log.v(TAG, e.getMessage());
        }
    }
};

private static File getOutputMediaFile() {
    String state = Environment.getExternalStorageState();
    if (!state.equals(Environment.MEDIA_MOUNTED)) {
        return null;
    }
    else {
        File folder_gui = new File(Environment.getExternalStorageDirectory() + File.separator + "GUI");
        if (!folder_gui.exists()) {
            Log.v(TAG, "Creating folder: " + folder_gui.getAbsolutePath());
            folder_gui.mkdirs();
        }
        File outFile = new File(folder_gui, "temp.jpg");
        Log.v(TAG, "Returnng file: " + outFile.getAbsolutePath());
        return outFile;
    }
}

单击按钮后，我得到日志：“现在将拍照”，“现在将释放相机”和“现在将调用完成”。活动成功完成，但在活动期间未调用回调函数

mCamera.takePicture(null, null, mPicture);

函数（没有来自 mPicture 回调或 getMediaOutputFile 函数的日志）并且在指定的位置没有文件。

有任何想法吗？：） 非常感谢！

4

2 回答 2

6

调用mCamera.takePicture()是异步的。这意味着调用立即完成，但实际的图片拍摄和处理发生在稍后的某个时间。但是，您在从调用返回时立即执行此操作mCamera.takePicture()：

Log.v(TAG, "will now release camera");
mCamera.release();
Log.v(TAG, "will now call finish()");
finish();

这意味着您已经释放了相机资源并在相机有机会实际拍照并给您回电之前完成了 Activity。

您需要将该代码移动到回调方法onPictureTaken()中，以便在回调发生后释放资源并完成 Activity。

于 2013-10-30T15:51:08.970 回答
0

这样做是为了通过单击使用 SurfaceView 自定义相机拍摄多张图像 

clickbtn.setOnClickListener(new OnClickListener() {

        @SuppressWarnings("deprecation")
        @Override
        public void onClick(View v) {

            for (int i = 0; i < 5; i++) {
                mcamera = mPreview.getCamera();

                getimage(mcamera);

                Toast.makeText(getApplicationContext(),
                        "multiple image count=" + i, 1000).show();

            }

            if (mPreview == null) {
                mPreview = new CamLayer(MainActivity.this);
            }


        }
    });

和

    public static void getimage(Camera mcamera) {


    PictureCallback mPicture = new PictureCallback() {

        @Override
        public void onPictureTaken(byte[] data, Camera camera) {
            pictureFile = getOutputMediaFile();
            Log.e("path file 11111111", ""+pictureFile);
            if (pictureFile == null) {
                return;
            }
            try {
                FileOutputStream fos = new FileOutputStream(pictureFile);
                fos.write(data);
                fos.close();

            } catch (FileNotFoundException e) {

            } catch (Exception e) {

            }
        }
    };
    try {

        mcamera.startPreview();
        mcamera.takePicture(null, null, mPicture);
        Thread.sleep(2000);

    } catch (Exception exception) {
        exception.printStackTrace();
    }

}

private static File getOutputMediaFile() {
    File mediaStorageDir = new File(
            Environment
                    .getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),
            "Sunil3");
    if (!mediaStorageDir.exists()) {
        if (!mediaStorageDir.mkdirs()) {

            return null;
        }
    }


    File mediaFile = new File(String.format(mediaStorageDir+File.separator+"%d.jpg", System.currentTimeMillis()));

    return mediaFile;
}
于 2015-01-28T07:52:25.620 回答