java - Android:捕获的图像未显示在图库中(媒体扫描器 Intent 不起作用)

Question

我有以下问题:我正在开发一个应用程序，用户可以在其中拍照(以附加到帖子中)并将图片保存到外部存储。我希望这张照片也显示在图片库中，为此我正在使用媒体扫描仪，但它似乎不起作用。我在编写代码时遵循的是官方 Android 开发人员指南，所以我不知道出了什么问题。

我的部分代码:

捕获图像的 Intent :

private void dispatchTakePictureIntent() {
    Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    // Ensure that there's a camera activity to handle the intent
    if (takePictureIntent.resolveActivity(getActivity().getPackageManager()) != null) {
        // Create the File where the photo should go
        File photoFile = null;
        try {
            photoFile = createImageFile();
        } catch (IOException ex) {
            // Error occurred while creating the File
            Toast.makeText(getActivity(), ex.getMessage(), Toast.LENGTH_SHORT).show();
        }
        // Continue only if the File was successfully created
        if (photoFile != null) {
            takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT,
                    Uri.fromFile(photoFile));
            startActivityForResult(takePictureIntent, REQUEST_IMAGE_CAPTURE);
        }
    }
}

创建一个文件来保存图像:

private File createImageFile() throws IOException {
    // Create an image file name
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
    String imageFileName = "JPEG_" + timeStamp + "_";
    File storageDir = Environment.getExternalStoragePublicDirectory(
            Environment.DIRECTORY_PICTURES);
    File image = File.createTempFile(
            imageFileName,  /* prefix */
            ".jpg",         /* suffix */
            storageDir      /* directory */
    );

    // Save a file: path for use with ACTION_VIEW intents
    mCurrentPhotoPath = image.getAbsolutePath();
    return image;
}

在 View 中显示图像:

private void setPic() {
    // Get the dimensions of the View
    int targetW = 60;
    int targetH = 100;

    // Get the dimensions of the bitmap
    BitmapFactory.Options bmOptions = new BitmapFactory.Options();
    bmOptions.inJustDecodeBounds = true;
    BitmapFactory.decodeFile(mCurrentPhotoPath, bmOptions);
    int photoW = bmOptions.outWidth;
    int photoH = bmOptions.outHeight;

    // Determine how much to scale down the image
    int scaleFactor = Math.min(photoW/targetW, photoH/targetH);

    // Decode the image file into a Bitmap sized to fill the View
    bmOptions.inJustDecodeBounds = false;
    bmOptions.inSampleSize = scaleFactor;
    bmOptions.inPurgeable = true;

    Bitmap bitmap = BitmapFactory.decodeFile(mCurrentPhotoPath, bmOptions);
    img_added.setImageBitmap(bitmap);
}

广播一个 Media Scanner Intent 使图像显示在图库中:

private void galleryAddPic() {
    Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
    File f = new File(mCurrentPhotoPath);
    Uri contentUri = Uri.fromFile(f);
    mediaScanIntent.setData(contentUri);
    getActivity().sendBroadcast(mediaScanIntent);
}

图像捕获 Intent 返回后运行的代码:

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {

    if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == Activity.RESULT_OK) {
        setPic();

        galleryAddPic();
    }
}

我也曾尝试使用 Intent.ACTION_MEDIA_MOUNTED 而不是 Intent.ACTION_MEDIA_SCANNER_SCAN_FILE，但在那种情况下我得到了“权限被拒绝”的错误。当我记录传递给 Intent 的 URI 时，我得到 file:///storage/emulated/0/Pictures/JPEG_20150803_104122_-1534770215.jpg，这应该没问题。除此以外，其他一切正常(捕获图像，将其保存到外部存储并在 View 中显示)，所以我真的不知道出了什么问题。有人有什么主意吗？提前致谢!

Answer 1

这取决于此设备Gallery 的实现方式。流行的照片应用接收 Intent.ACTION_MEDIA_SCANNER_SCAN_FILE 广播，但有些只听 Android 媒体数据库。

或者，您可以同时手动将图像插入 MediaStore。

public final void notifyMediaStoreScanner(final File file) {
        try {
            MediaStore.Images.Media.insertImage(mContext.getContentResolver(),
                    file.getAbsolutePath(), file.getName(), null);
            mContext.sendBroadcast(new Intent(
                    Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.fromFile(file)));
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }

此外，请确保您的照片不在private 文件夹中，例如内部存储或使用Context.MODE_PRIVATE 写入。否则其他应用将无权访问此文件。