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Android: decodeFile always returns null for file in internal storage

开发者 https://www.devze.com 2023-03-05 22:38 出处:网络
I have a file saved locally into the application\'s private storage. I have verified it exists, however whenever I call BitmapFactory.decodeFile it always returns null.

I have a file saved locally into the application's private storage. I have verified it exists, however whenever I call BitmapFactory.decodeFile it always returns null.

If I save the file as a resource and use ImageView.setImageResource, it always shows up fine.开发者_Python百科

What is the problem?

Here is the snippet:

filename = "test.png";

if (doesFileExist(filename))
    Bitmap bMap = BitmapFactory.decodeFile(filename);

I've also tried:

Bitmap bMap = BitmapFactory.decodeFile(getFilesDir().getPath()
                    + filename);


This question has been answered before such as here: BitmapFactory.decodeFile returns null even image exists

This was exactly what I needed:

String fname=new File(getFilesDir(), "test.png").getAbsolutePath();


Instead of using BitmapFactory.decodeFile, try using InputStream:

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

    if(resultCode == RESULT_OK){          
        Uri selectedImage = imageReturnedIntent.getData();
        InputStream imageStream = getContentResolver().openInputStream(selectedImage);
        Bitmap yourSelectedImage = BitmapFactory.decodeStream(imageStream);


Folks, files stored in app resource should be referenced in special way. E.g. if file is located in assets and named as "myfile.png" it has to be referenced as:

String uriString="file:///android_asset/myfile.png";
Uri uri=Uri.parse(uriString);


BitmapFactory.decodeFile expects a file path without the scheme. I.e. without the file:// in the beginning.

If you're handling a Uri, don't just .toString() it, but instead call .getPath() on it, and pass that to the method.


After adding the required permissions (READ_EXTERNAL_STORAGE, WRITE_EXTERNAL_STORAGE)

You need to add this line to manifests: android:requestLegacyExternalStorage="true"

Android: decodeFile always returns null for file in internal storage


Could you try fileList()? It

returns an array of strings naming the private files associated with this Context's application package.


For me I was getting image from locally saved URL something like "file:///storage/emulated/0/...." (I have used Phonegap plugin to capture image. Plugin was giving me image path, which I need to use in native code)

Here is the code snippet which worked for me.

String captured_image_info = "file:///storage/emulated/0/Android/data/com.testapp/cache/1493809796526.jpg"
Uri uri=Uri.parse(captured_image_info);
largeLog("uri", "" + uri);

InputStream imageStream = getContentResolver().openInputStream(uri);

Bitmap bm = BitmapFactory.decodeStream(imageStream);

ByteArrayOutputStream baos = new ByteArrayOutputStream();

bm.compress(Bitmap.CompressFormat.JPEG, 100, baos); //bm is the bitmap object

byte[] decodedBytes = baos.toByteArray();

Bitmap img_captured_image = BitmapFactory.decodeByteArray(decodedBytes, 0, decodedBytes.length);


You need to setup run-time permissions for Manifest.permission.READ_EXTERNAL_STORAGE If you don't you'll get a null without getting any error message or even an indication in the Log. Note that you need to request the permissions both in the Manifest and at run time.

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