如何在自定义文件夹中添加数据与ContentResolver ?

Question

我在图片文件夹中创建了MyAppImages文件夹。我想在这个文件夹中保存一个新图像。

当我通过ContentResolver插入MediaStore.Image.Media.EXTERNAL_CONTENT_URI时，我可以直接将图片保存到Pictures文件夹中。

当我通过uri使用FileProvider添加我自己的文件夹时，我得到java.lang.UnsupportedOperationException: No external inserts错误。

当我用Uri.fromFile(myDirFile)添加我自己的文件夹时，我得到java.lang.IllegalArgumentException: Unknown URL file:///storage/emulated/0/Android/data/com.my.app/files/Pictures/MyApp%20Image错误。然而，当我调用myDirFile.exists()时，它返回true。

我代码:

private void saveByteToFile(byte[] byteArray, String contentType, long seconds){
File storageDir = getContext().getExternalFilesDir(Environment.DIRECTORY_PICTURES);

//getOrCreate MyApp Images directory
File myDirFile = new File(attachmentDir.getAbsolutePath(), "MyApp Images"); 
//first error I mentioned
//Uri myDirUri = FileProviderUtil.getUriFor(MyApplication.getContext(), myDirFile); 
//second error I mentioned
Uri myDirUri = Uri.fromFile(myDirFile);

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
if (!myDirFile.exists())
Files.createDirectory(Paths.get(myDirFile.getAbsolutePath()));
} else {
myDirFile.mkdirs();
}
Logger.i(myDirFile.exists() + " myDirUri: " + myDirUri); //exists return true
ContentValues contentValues = new ContentValues();
contentValues.put(MediaStore.MediaColumns.DISPLAY_NAME, fileName);
contentValues.put(MediaStore.MediaColumns.MIME_TYPE, contentType);
contentValues.put(MediaStore.MediaColumns.DATE_ADDED, seconds);
contentValues.put(MediaStore.MediaColumns.DATE_MODIFIED, seconds);
contentValues.put(MediaStore.Images.Media.DATA, myDirFile.getAbsolutePath());
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
contentValues.put(MediaStore.MediaColumns.IS_PENDING, 1);
}
ContentResolver resolver = getContext().getContentResolver();
try {
Uri outputUri = resolver.insert(myDirUri, contentValues); //->the errors I mentioned here are returning
if (outputUri == null)
throw new IOException("Failed to create new MediaStore record.");
try (final OutputStream stream = resolver.openOutputStream(outputUri)) {
if (stream == null)
throw new IOException("Failed to open output stream.");
stream.write(byteArray);
} finally {
if (Build.VERSION.SDK_INT > 28) {
ContentValues updateValues = new ContentValues();
updateValues.put(MediaStore.MediaColumns.IS_PENDING, 0);
resolver.update(outputUri, updateValues, null, null);
}
}
return outputUri;
} catch (IOException e) {
Logger.exception(e);
throw e;
}
}

Answer 1

看这个，它可能对你有帮助。

private fun saveImage(bmp: Bitmap) {
var imageOutStream: OutputStream
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
val values = ContentValues()
//image name
values.put(MediaStore.Images.Media.DISPLAY_NAME, "image.jpg");
// image type
values.put(MediaStore.Images.Media.MIME_TYPE, "image/jpeg");
//storage path
values.put(MediaStore.Images.Media.RELATIVE_PATH, "DCIM/" + "Camera");
val uri = requireContext().contentResolver.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values)
imageOutStream = uri?.let { requireContext().getContentResolver().openOutputStream(it) }!!
}
else
{
//creating directory and saving
val imagesDir =
Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES).toString()
val image = File(imagesDir, "image.jpg")
imageOutStream =  FileOutputStream(image);
}
//compreesing the image
bmp.compress(Bitmap.CompressFormat.JPEG, 100, imageOutStream);
Toast.makeText(requireContext(),"ImageSaved",Toast.LENGTH_LONG).show()
imageOutStream.close();
}