Question

我在我的Android应用中使用了滑动库。

我想告诉它重新获取图像X次（可能是指数退避！），然后放弃并显示错误占位符图像。

知道怎么做吗？（我正在使用Volley整合btw）。

Answer 1

使用您自己的ResourceDecoder。我只加载本地文件并处理decode()中的重试次数。如果您使用其他模型，只需更改为适当的界面。

Glide 4.0.0-SNAPSHOT的实施例。自定义ResourceDecoder：

public class FileDecoder implements ResourceDecoder<File, Drawable>{
    private final Context context;
    private int retryCounter = 0;

    public FileDecoder(Context context) {
        this.context = context;
    }

    @Override
    public Resource<Drawable> decode(File source, int width, int height, Options options) throws IOException{

        source = getTheFile(); //loading the image from a zip

        final Drawable icon = Drawable.createFromPath(source.getAbsolutePath());
        if(icon == null){
            if(retryCounter < 3){
                retryCounter++;
                return decode(source, width, height, options);
            }

            return null;
        }

        return new DrawableResource<Drawable>(icon) {
            @Override public Class<Drawable> getResourceClass() {
                return Drawable.class;
            }

            @Override public int getSize() {
                if (drawable instanceof BitmapDrawable) {
                    return Util.getBitmapByteSize(((BitmapDrawable) drawable).getBitmap());
                } else {
                    return 1;
                }
            }

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

    @Override public boolean handles(File source, Options options) throws IOException {
        return true;
    }
}

必需的自定义ModelLoader

public class FileModelLoader implements ModelLoader<File, File>{

    @Nullable @Override
    public LoadData<File> buildLoadData(final File file, int width, int height, Options options){
        return new LoadData<>(new ObjectKey(file), new DataFetcher<File>() {
            @Override
            public void loadData(Priority priority, DataCallback<? super File> callback) {
                callback.onDataReady(file);
            }

            @Override public void cleanup() {

            }

            @Override public void cancel() {

            }

            @Override public Class<File> getDataClass() {
                return File.class;
            }

            @Override public DataSource getDataSource() {
                return DataSource.LOCAL;
            }
        });
    }

    @Override public boolean handles(File file){
        return true;
    }
}

注册您的自定义模块

public class CustomGlideModule implements GlideModule{

    @Override public void applyOptions(Context context, GlideBuilder builder){
        builder.setDefaultRequestOptions(RequestOptions.formatOf(DecodeFormat.PREFER_RGB_565)); //less memory consumption but less quality
    }

    @Override public void registerComponents(Context context, Registry registry){
        registry.append(File.class, File.class, new ModelLoaderFactory<File, File>(){
            @Override public ModelLoader<File, File> build(MultiModelLoaderFactory multiFactory){
                return new FileModelLoader();
            }

            @Override public void teardown(){

            }
        }).append(File.class, Drawable.class, new FileDecoder(context));
    }
}

添加到mainfest

<application>
    ...

    <meta-data
    android:name="com.fileloader.glide.CustomGlideModule"
    android:value="GlideModule" />

</application>

如何使用Glide for Android指定重试次数以加载图像？

1 个答案: