Android-confirm whether the ImageView image is successfully loaded

Android-confirm whether the ImageView image is successfully loaded
Check whether the image of ImageView is successfully loaded.

 

 

 

JudgmentImageView ImageWhether the image exists. If the image is not loaded successfully, the default image is displayed.

If (mPhotoView. getDrawable () = null) {// Toast. makeText (getActivity (), image loading failed, Toast. LENGTH_SHORT ). show (); mPhotoView. setImageDrawable (getResources (). getDrawable (R. drawable. icon_default_user_photo ));}

Conversion between Bitmap, Drawable, Byte, and ID in Android
1. Bitmap is converted to byte

ByteArrayOutputStream out = new ByteArrayOutputStream();bitmap.compress(Bitmap.CompressFormat.PNG, 100, out);byte[] array= out.toByteArray();

2. byte conversion to bitmap

Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);

3. bitmap conversion to Drawable

Drawable drawable = new FastBitmapDrawable(bitmap);

4. Drawable conversion to bitmap
A. BitmapDrawable and FastBitmapDrawable use getBitmap directly
B. Draw other types of Drawable TO A bitmap Using Canvas.

      Canvas canvas = new Canvas(bitmap)      drawable.draw(canvas)

5. id conversion graphic. drawable

Drawable drawable = activity.getResources().getDrawable(R.drawable.icon);

6. Convert id to Bitmap

Bitmap bitmap = BitmapFactory. decodeResource (Resources   res, int id)