使用Android数据绑定时,如何访问BindingAdapter中的实例变量？

Question

所以我使用这个流行的数据绑定代码片段通过传入URL将图像加载到列表项的imageview中:

  <ImageView
        android:layout_width="match_parent"
        android:layout_height="150dp""
        app:imageUrl="@{movie.imageUrl}"
        />

绑定适配器:

class Movie{
    boolean isLoaded;

    @BindingAdapter({"bind:imageUrl"})
        public static void loadImage(final ImageView view, String imageUrl) {

            Picasso.with(view.getContext())
                .load(imageUrl)
                .into(view, new Callback.EmptyCallback() {
                @Override public void onSuccess() {
                    //set isLoaded to true for the listview item
                    // but cannot access boolean isLoaded as it is non static.
                });
    }

如果我只是使BindingAdapter非静态,那么它会抛出错误:

java.lang.IllegalStateException: Required DataBindingComponent is null     in class MovieTileBinding. A BindingAdapter in     com.example.moviesapp.Pojos.Results is not static and requires an object to     use, retrieved from the DataBindingComponent. If you don't use an inflation method taking a DataBindingComponent, use DataBindingUtil.setDefaultComponent or make all BindingAdapter methods static.

Answer 1

通过自定义投标适配器放置整个电影实例：

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 <ImageView\n        android:layout_width="match_parent"\n        android:layout_height="150dp""\n        app:movie="@{movie}"\n        />\n

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绑定适配器：

\n\n

class Movie{\nboolean isLoaded;\n\n@BindingAdapter({"movie"})\n    public static void loadImage(final ImageView view, final Movie movie) {\n        if(movie != null &&\xc2\xa0moview.getImageUrl() != null){\n          Picasso.with(view.getContext())\n             .load(movie.getImageUrl())\n             .into(view, new Callback.EmptyCallback() {\n             @Override public void onSuccess() {\n                 image.setLoaded(true);\n             });\n     }\n}\n

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