Download image from URL, show it as a circular ima

问题:

After stucking few days on that problem I just wanted to share my solution with you and save your time.

Problem
1. Download an image from any URL
2. Show it as a circular image (if download succeeded)
3. Or show a default image in the same ImageView (if download failed)

[EDIT] I removed my answer because of very useful hints coming from @Budius and the better working solution which he offers below

回答1:

Best way to achieve the task from the question is using Picasso with a circular transformation.

Like the following code:

Picasso
  .with(context)
  .load(url)
  .placeholder(placeHolderDrawable)
  .error(errorDrawable)
  .transform(circleTransform)
  .into(imageView);

and the code for the circleTransform copied from this link: https://gist.github.com/julianshen/5829333

public class CircleTransform implements Transformation {
    @Override
    public Bitmap transform(Bitmap source) {
        int size = Math.min(source.getWidth(), source.getHeight());

        int x = (source.getWidth() - size) / 2;
        int y = (source.getHeight() - size) / 2;

        Bitmap squaredBitmap = Bitmap.createBitmap(source, x, y, size, size);
        if (squaredBitmap != source) {
            source.recycle();
        }

        Bitmap bitmap = Bitmap.createBitmap(size, size, source.getConfig());

        Canvas canvas = new Canvas(bitmap);
        Paint paint = new Paint();
        BitmapShader shader = new BitmapShader(squaredBitmap, BitmapShader.TileMode.CLAMP, BitmapShader.TileMode.CLAMP);
        paint.setShader(shader);
        paint.setAntiAlias(true);

        float r = size/2f;
        canvas.drawCircle(r, r, r, paint);

        squaredBitmap.recycle();
        return bitmap;
    }

    @Override
    public String key() {
        return "circle";
    }
}

回答2:

compile 'com.squareup.picasso:picasso:2.5.0'//for load image from URL
compile 'de.hdodenhof:circleimageview:1.3.0'//for circle imageview

//add view in xml file
<de.hdodenhof.circleimageview.CircleImageView
                    android:id="@+id/ivProfileImage"
                    android:layout_width="100dp"
                    android:layout_height="100dp"
                    android:layout_centerHorizontal="true"
                    android:layout_margin="10dp"
                    android:contentDescription="@null"
                    app:border_color="#ffffff"
                    app:border_width="2dp" />
//Load image from Java file
private CircleImageView mIvProfileImage;
mIvProfileImage = (CircleImageView) findViewById(R.id.ivProfileImage);    
Picasso.with(getApplicationContext()).load("IMAGE URL")//download URL
.placeholder(R.drawable.ic_user_class)//use defaul image
.error(R.drawable.ic_user_class)//if failed                           
.into(mIvProfileImage);//imageview