How To Load Layout Background Using Picasso

问题:

Can anyone point me towards an example of how one might change an XML layout's background programatically using Picasso? All the examples I've found are able to update an ImageView using Picasso - but not a layout background.

Unable to set LinearLayout BackgroundResource from URL using Picasso

回答1:

You can use Picasso's Target:

         Picasso.with(this).load("http://imageUrl").into(new Target() {
            @Override
            public void onBitmapLoaded(Bitmap bitmap, Picasso.LoadedFrom from) {
               mYourLayout.setBackground(new BitmapDrawable(bitmap));
            }

            @Override
            public void onBitmapFailed(Drawable errorDrawable) {

            }

            @Override
            public void onPrepareLoad(Drawable placeHolderDrawable) {

            }
        });

UPDATE

As @BladeCoder mentioned in the comment, Picasso holds a weak reference to Target objects, hence it is likely to be garbage collected.

So, following Jake Wharton's comment on one of the issues, i think this could be a good way to go:

  CustomLayout mCustomLayout = (CustomLayout)findViewById(R.id.custom_layout)
  Picasso.with(this).load("http://imageUrl").into(mCustomLayout);

CustomLayout.java:

public class CustomLayout extends LinearLayout implements Target {

    public CustomLayout(Context context) {
        super(context);
    }

    public CustomLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public CustomLayout(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }


    @Override
    public void onBitmapLoaded(Bitmap bitmap, Picasso.LoadedFrom from) {
        setBackground(new BitmapDrawable(getResources(), bitmap));
    }

    @Override
    public void onBitmapFailed(Drawable errorDrawable) {
        //Set your error drawable
    }

    @Override
    public void onPrepareLoad(Drawable placeHolderDrawable) {
        //Set your placeholder
    }
}

回答2:

I use an ImageView as temporary ImageHolder. At first, load image with picasso into ImageView and set Layout Background from this ImageView by using getDrawable.

               ImageView img = new ImageView(this);
               Picasso.with(this)
              .load(imageUri)
              .fit()
              .centerCrop()
              .into(img, new Callback() {
                        @Override
                        public void onSuccess() {

                            myLayout.setBackgroundDrawable(img.getDrawable());
                        }

                        @Override
                        public void onError() {

                        }
                    });

回答3:

None of the solutions above worked for me. But @Thiha's solution was the closest. The below worked for me:

final ImageView img = new ImageView(this);
    Picasso.with(img.getContext()).load(url).into(img, new com.squareup.picasso.Callback() {
        @Override
        public void onSuccess() {
            collapsingToolbarLayout.setBackgroundDrawable(img.getDrawable());
        }

        @Override
        public void onError() {
        }
    });

回答4:

In my case i needed the image to fit the imageview's size so instead of loading the image in background i added this property to the imageview and loaded the image normally.

android:scaleType="fitXY"