使用 Fresco 设置 TextView 的左侧可绘制对象

Setting TextView's left drawable with Fresco

使用本指南,我已经为此苦苦挣扎了一段时间:

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

但是建议自己写onDraw方法,我只想设置TextView的复合drawable。我该怎么做?

您不需要重写 onDraw,因为 TextView 已经为您完成了。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()));
  }

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(...)

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。