ImageView setImageBitmap在某些设备上不起作用

Question

我正在尝试Camera API以下操作：

一种。为拍摄的图像设置目录（用于startActivityForResult）

b。设置位图，以便将图像保存到应用程序本身后即可显示。

这是以下代码：

设置目录。

private static File getOutputMediaFile(int type) {

    // External sdcard location
    File mediaStorageDir = new File(
            Environment
                    .getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),
            IMAGE_DIRECTORY_NAME);
    // Create the storage directory if it does not exist
    if (!mediaStorageDir.exists()) {
        if (!mediaStorageDir.mkdirs()) {
            Log.d(IMAGE_DIRECTORY_NAME, "Oops! Failed create "
                    + IMAGE_DIRECTORY_NAME + " directory");
            return null;
        }
    }
    // Create a media file name
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss",
            Locale.getDefault()).format(new Date());
    File mediaFile;
    if (type == MEDIA_TYPE_IMAGE) {
        mediaFile = new File(mediaStorageDir.getPath() + File.separator
                + "IMG_" + timeStamp + ".jpg");
    } else {
        return null;
    }

    return mediaFile;
}

应用程序中的全局变量

// Activity request codes
private static final int CAMERA_CAPTURE_IMAGE_REQUEST_CODE = 100;
public static final int MEDIA_TYPE_IMAGE = 1;

// directory name to store the captured images
private static final String IMAGE_DIRECTORY_NAME = "my_camera_app";

private Uri fileUri;

// Views
ImageView photo;
Button camera;

相机实现逻辑

// Use camera function
private void captureImage() {
    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

    fileUri = getOutputMediaFileUri(MEDIA_TYPE_IMAGE);

    intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);

    // start the image capture Intent
    startActivityForResult(intent, CAMERA_CAPTURE_IMAGE_REQUEST_CODE);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    // TODO Auto-generated method stub
    if (requestCode == CAMERA_CAPTURE_IMAGE_REQUEST_CODE) {
        if (resultCode == RESULT_OK) {
            // Successfully captured the image
            // display in imageview
            previewImage();
        } else {
            // failed to capture image
            Toast.makeText(getApplicationContext(),
                    "Sorry! Failed to capture image", Toast.LENGTH_SHORT)
                    .show();
        }
    }
}

private void previewImage() {
    try {
        // Bitmap factory
        BitmapFactory.Options options = new BitmapFactory.Options();

        // Downsizing image as it throws OutOfMemory exception for larger
        // images
        options.inSampleSize = 3;

        final Bitmap bitmap = BitmapFactory.decodeFile(fileUri.getPath(),
                options);

        photo.setImageBitmap(bitmap);

    } catch (NullPointerException e) {
        e.printStackTrace();
    }
}

我遇到的问题是...对于我测试过该应用程序的某些设备，该应用程序显示所拍摄图像的空白预览，而在其他设备中，该应用程序运行良好。

为什么我得到一个空白的反馈？在某些情况下，保存图像时，不会将用户定向到我的应用，而是将用户卡在相机应用中。

请帮忙。

Answer 1

我解决这个问题的一种方法是在设置时FileUri，我存储了Uriusing SharedPreferences。所以在我的代码中：

public void takePhoto() {
    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    fileUri = FileHelper.getOutputMediaFileUri();
    // Store uri to SharedPreferences
    pref.setImageUri(fileUri.toString());
    intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);
    startActivityForResult(intent, TAKE_PICTURE);
}

在我的onActivityResult回调中：

if (requestCode == TAKE_PICTURE && resultCode == RESULT_OK) {
    // If user is taking photo then only call the SharedPreferences
    // If user is selecting photo from gallery, we can use the Intent data
    fileUri = Uri.parse(pref.getImageUri());
    if (fileUri.getPath().toString().length() < 1) {
        Toast.makeText(getApplicationContext(),
                "Sorry something went wrong ... Please try again",
                Toast.LENGTH_LONG).show();
    } else {
        String path = fileUri.getPath().toString();
        db_img_path = path;
        imageholder.setVisibility(View.VISIBLE);
        Bitmap bitmap = PathtoImage.previewImage(path);
        imagepreview.setImageBitmap(bitmap);
    }
}

奖金 ：）

在我的previewImage方法中，我对方向进行了调整，代码如下所示：

public static Bitmap previewImage(String path) {
    BitmapFactory.Options options = new BitmapFactory.Options();
    options.inSampleSize = 4;
    final Bitmap bitmap = BitmapFactory.decodeFile(path, options);
    // Providing adjustment so that the image is shown in the correct orientation
    Matrix adjustment = adjustOrientation(path);
    Bitmap resizedBitmap = Bitmap.createBitmap(bitmap, 0, 0,
            bitmap.getWidth(), bitmap.getHeight(), adjustment, true);
    return resizedBitmap;
}

在这个方法中，我调用了另一个方法adjustOrientation来修复Matrix图像。

// Adjustment for orientation of images
public static Matrix adjustOrientation(String path) {
    Matrix matrix = new Matrix();
    try {
        ExifInterface exifReader = new ExifInterface(path);

        int orientation = exifReader.getAttributeInt(
                ExifInterface.TAG_ORIENTATION, -1);

        if (orientation == ExifInterface.ORIENTATION_NORMAL) {
            // do nothing
        } else if (orientation == ExifInterface.ORIENTATION_ROTATE_90) {
            matrix.postRotate(90);
        } else if (orientation == ExifInterface.ORIENTATION_ROTATE_180) {
            matrix.postRotate(180);
        } else if (orientation == ExifInterface.ORIENTATION_ROTATE_270) {
            matrix.postRotate(270);
        }

    } catch (IOException e) {
        e.printStackTrace();
    }

    return matrix;
}

这是我对这个问题的实现，如果有人对此有更好的实现，请发帖:)