Sharing Bitmap via Android Intent

问题:

In my android app, I have a bitmap (say b) and a button. Now when I click on the button, I want to share the bitmap. I am making use of the below code inside my onClick() to achieve this :-

Intent intent = new Intent(Intent.ACTION_SEND);
intent.setType("image/png");
intent.putExtra(Intent.EXTRA_STREAM, b);
startActivity(Intent.createChooser(intent , "Share"));

I was expecting a list of all application which are able to handle this intent but I get nothing. There is no list of apps nor is there any error in android studio. My application just get hanged for sometime and then quits.

I have checked the bitmap and it is fine (its not null).

Where am I a going wrong ?

回答1:

As CommonsWare stated you need to get the URI to the bitmap and pass that as your Extra.

String bitmapPath = Images.Media.insertImage(getContentResolver(), bitmap,"title", null);
Uri bitmapUri = Uri.parse(bitmapPath);
...
intent.putExtra(Intent.EXTRA_STREAM, bitmapUri );

回答2:

I found out 2 variants of the solution. Both are saving Bitmap to the storage, but the image is not showed in the gallery.

First variant:

Saving to external storage - but to private folder of the app. - for API <= 18 it requires permission, for newer it does not.

1. Setting permissions

Add into AndroidManifest.xml before tag

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"android:maxSdkVersion="18"/>

2. Saving method:

 /**
 * Saves the image as PNG to the app's private external storage folder.
 * @param image Bitmap to save.
 * @return Uri of the saved file or null
 */
private Uri saveImageExternal(Bitmap image) {
    //TODO - Should be processed in another thread
    Uri uri = null;
    try {
        File file = new File(getExternalFilesDir(Environment.DIRECTORY_PICTURES), "to-share.png");
        FileOutputStream stream = new FileOutputStream(file);
        image.compress(Bitmap.CompressFormat.PNG, 90, stream);
        stream.close();
        uri = Uri.fromFile(file);
    } catch (IOException e) {
        Log.d(TAG, "IOException while trying to write file for sharing: " + e.getMessage());
    }
    return uri;
}

3. Checking storage accesibility

External storage might not be accessible, so you should check it before trying to save - https://developer.android.com/training/data-storage/files

/**
 * Checks wheather the external storage is writable.
 * @return true if storage is writable, false otherwise
 */
public boolean isExternalStorageWritable() {
    String state = Environment.getExternalStorageState();
    if (Environment.MEDIA_MOUNTED.equals(state)) {
        return true;
    }
    return false;
}

Second variant

Saving to cacheDir using FileProvider. It does not require any permission.

1. Setup FileProvider in AndroidManifest.xml

<manifest>
    ...
    <application>
        ...
        <provider
            android:name="android.support.v4.content.FileProvider"
            android:authorities="com.mydomain.fileprovider"
            android:exported="false"
            android:grantUriPermissions="true">
                <meta-data
                    android:name="android.support.FILE_PROVIDER_PATHS"
                    android:resource="@xml/file_paths" />
        </provider>
        ...
    </application>
</manifest>

2. Add path to the res/xml/file_paths.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <paths xmlns:android="http://schemas.android.com/apk/res/android">
         <cache-path name="shared_images" path="images/"/>
    </paths>
</resources>

3. Saving method:

    /**
 * Saves the image as PNG to the app's cache directory.
 * @param image Bitmap to save.
 * @return Uri of the saved file or null
 */
private Uri saveImage(Bitmap image) {
    //TODO - Should be processed in another thread
    File imagesFolder = new File(getCacheDir(), "images");
    Uri uri = null;
    try {
        imagesFolder.mkdirs();
        File file = new File(imagesFolder, "shared_image.png");

        FileOutputStream stream = new FileOutputStream(file);
        image.compress(Bitmap.CompressFormat.PNG, 90, stream);
        stream.flush();
        stream.close();
        uri = FileProvider.getUriForFile(this, "com.mydomain.fileprovider", file);

    } catch (IOException e) {
        Log.d(TAG, "IOException while trying to write file for sharing: " + e.getMessage());
    }
    return uri;
}

More info about file provider - https://developer.android.com/reference/android/support/v4/content/FileProvider

Compressing and saving can be time-consuming and should be done in different thread

Actual sharing

/**
 * Shares the PNG image from Uri.
 * @param uri Uri of image to share.
 */
private void shareImageUri(Uri uri){
    Intent intent = new Intent(android.content.Intent.ACTION_SEND);
    intent.putExtra(Intent.EXTRA_STREAM, uri);
    intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
    intent.setType("image/png");
    startActivity(intent);
}

回答3:

** finally i got the solution.**

Step 1 : Share Intent handling Block. This will Pop Up your window with list of Applications in you phone

public void share_bitMap_to_Apps() {

    Intent i = new Intent(Intent.ACTION_SEND);

    i.setType("image/*");
    ByteArrayOutputStream stream = new ByteArrayOutputStream();
    /*compress(Bitmap.CompressFormat.PNG, 100, stream);
    byte[] bytes = stream.toByteArray();*/


    i.putExtra(Intent.EXTRA_STREAM, getImageUri(mContext, getBitmapFromView(relative_me_other)));
    try {
        startActivity(Intent.createChooser(i, "My Profile ..."));
    } catch (android.content.ActivityNotFoundException ex) {

        ex.printStackTrace();
    }


}

Step 2 : Converting your view to BItmap

public static Bitmap getBitmapFromView(View view) {
    //Define a bitmap with the same size as the view
    Bitmap returnedBitmap = Bitmap.createBitmap(view.getWidth(),      view.getHeight(), Bitmap.Config.ARGB_8888);
    //Bind a canvas to it
    Canvas canvas = new Canvas(returnedBitmap);
    //Get the view's background
    Drawable bgDrawable = view.getBackground();
    if (bgDrawable != null)
        //has background drawable, then draw it on the canvas
        bgDrawable.draw(canvas);
    else
        //does not have background drawable, then draw white background on the canvas
        canvas.drawColor(Color.WHITE);
    // draw the view on the canvas
    view.draw(canvas);
    //return the bitmap
    return returnedBitmap;
}

Step 3 :

To get The URI from Bitmap Image

public Uri getImageUri(Context inContext, Bitmap inImage) {
    ByteArrayOutputStream bytes = new ByteArrayOutputStream();
    inImage.compress(Bitmap.CompressFormat.JPEG, 100, bytes);

    String path = MediaStore.Images.Media.insertImage(inContext.getContentResolver(), inImage, "Title", null);
    return Uri.parse(path);
}

回答4:

Quoting the documentation:

A content: URI holding a stream of data associated with the Intent, used with ACTION_SEND to supply the data being sent.

b, therefore, is not supposed to be a Bitmap, but rather a Uri pointing to a Bitmap, served by a ContentProvider. For example, you could write the Bitmap to a file, then use FileProvider to serve it.

回答5:

ImageButton capture_share = (ImageButton) findViewById(R.id.share);
capture_share.setOnClickListener(new View.OnClickListener() {
  @Override
  public void onClick(View view) {

    String bitmapPath = MediaStore.Images.Media.insertImage(getContentResolver(), bitmap,"title", null);
    Uri bitmapUri = Uri.parse(bitmapPath);

        Intent intent = new Intent(Intent.ACTION_SEND);
        intent.setType("image/png");
        intent.putExtra(Intent.EXTRA_STREAM, bitmapUri);
        startActivity(Intent.createChooser(intent, "Share"));



  }
});

回答6:

After spending a lot of time on this:

Check if permissions are given. Then:

Step 1: Create ImageView of the image you want to in the activity and then convert it itno bitmap

ImageView imageView = findViewById(R.id.image);
Bitmap bitmap = ((BitmapDrawable) imageView.getDrawable()).getBitmap();

//save the image now:
saveImage(bitmap);
//share it
send();

Step 2: Store the image in internal folder:

private static void saveImage(Bitmap finalBitmap) {

    String root = Environment.getExternalStorageDirectory().getAbsolutePath();
    File myDir = new File(root + "/saved_images");
    Log.i("Directory", "==" + myDir);
    myDir.mkdirs();

    String fname = "Image-test" + ".jpg";
    File file = new File(myDir, fname);
    if (file.exists()) file.delete();
    try {
        FileOutputStream out = new FileOutputStream(file);
        finalBitmap.compress(Bitmap.CompressFormat.JPEG, 90, out);
        out.flush();
        out.close();

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

Step 3: Send the saved image:

public void send() {
    try {
        File myFile = new File("/storage/emulated/0/saved_images/Image-test.jpg");
        MimeTypeMap mime = MimeTypeMap.getSingleton();
        String ext = myFile.getName().substring(myFile.getName().lastIndexOf(".") + 1);
        String type = mime.getMimeTypeFromExtension(ext);
        Intent sharingIntent = new Intent("android.intent.action.SEND");
        sharingIntent.setType(type);
        sharingIntent.putExtra("android.intent.extra.STREAM", Uri.fromFile(myFile));
        startActivity(Intent.createChooser(sharingIntent, "Share using"));
    } catch (Exception e) {
        Toast.makeText(getBaseContext(), e.getMessage(), Toast.LENGTH_SHORT).show();
    }
}

Now after sending you can delete the saved image if you don't want it in your storage. Check other link to do that.