android - Setting TextView's left drawable with Fresco

Question

I've been struggling with this for a while now, using this guide:

http://frescolib.org/docs/writing-custom-views.html

But it suggests writing my own onDraw method, I just want to set TextView's compound drawable. How do I do that?

Answer 1

你不需要重写 onDraw，因为 TextView 已经为你做了。你可以这样做：

class MyTextView extends TextView {
  MultiDraweeHolder mMultiDraweeHolder;

  // called from constructors
  private void init() {
    mMultiDraweeHolder = new MultiDraweeHolder<GenericDraweeHierarchy>();
    GenericDraweeHierarchyBuilder builder = 
        new GenericDraweeHierarchyBuilder(getResources());
    for (int i = 0; i < 4; i++) {
      GenericDraweeHierarchy hierarchy = builder.reset()
        .set...
        .build();
      mMultiDraweeHolder.add(
          new DraweeHolder<GenericDraweeHierarchy>(hierarchy, getContext()));
  }

要实际设置 URI 和边界：

// build DraweeController as in Fresco docs
DraweeHolder<GenericDraweeHierarchy> holder = mMultiDraweeHolder.get(i);
holder.setController(controller);
holder.getTopLevelDrawable().setBounds(...)

要将它们分配给您的 TextView：

List<Drawable> drawables = new ArrayList<>();
for (int i = 0; i < 4; i++) {
  drawables.add(mMultiDraweeHolder.get(i).getTopLevelDrawable());
}
setCompoundDrawables(
    drawables.get(0), drawables.get(1), drawables.get(2), drawables.get(3));

您的 TextView 仍然需要覆盖 onDetachedFromWindow 和文档中解释的其他方法，但您应该能够按原样粘贴该代码。