MainActivity.java 文件源码

private void displayImage(SimpleDraweeView draweeView, String url) {
    GenericDraweeHierarchy hierarchy = draweeView.getHierarchy();
    //设置占位图
    if (hierarchy == null) {
        hierarchy = GenericDraweeHierarchyBuilder.newInstance(getResources())
                .setPlaceholderImage(getResources().getDrawable(R.mipmap.ic_launcher)
                        , ScalingUtils.ScaleType.CENTER).build();
        draweeView.setHierarchy(hierarchy);
    } else {
        hierarchy.setPlaceholderImage(getResources().getDrawable(R.mipmap.ic_launcher)
                , ScalingUtils.ScaleType.CENTER);
    }

    //构建ImageRequestBuilder，传入请求Uri
    ImageRequestBuilder requestBuilder = ImageRequestBuilder.newBuilderWithSource(Uri.parse(url));
    //构建Controller
    DraweeController controller = Fresco.newDraweeControllerBuilder()
            .setOldController(draweeView.getController())
            .setImageRequest(requestBuilder.build())
            .build();
    //设置图片，Fresco设置显示图片都是通过Controller来实现
    draweeView.setController(controller);
}