public class Png {
    public Png(byte[] resource) {
        this.resource = resource;
    }

    public final byte[] resource;
}

public class PngBitmapBytesTranscoder implements ResourceTranscoder<Bitmap, Png> {
    private final Bitmap.CompressFormat compressFormat;
    private final int quality;

    public PngBitmapBytesTranscoder() {
        this(Bitmap.CompressFormat.PNG, 100);
    }

    @SuppressWarnings("WeakerAccess")
    public PngBitmapBytesTranscoder(@NonNull Bitmap.CompressFormat compressFormat, int quality) {
        this.compressFormat = compressFormat;
        this.quality = quality;
    }

    @Nullable
    @Override
    public Resource<Png> transcode(
            @NonNull Resource<Bitmap> toTranscode, @NonNull Options options) {
        ByteArrayOutputStream os = new ByteArrayOutputStream();
        toTranscode.get().compress(compressFormat, quality, os);
        toTranscode.recycle();
        Png png = new Png(os.toByteArray());
        return new PngResource(png);
    }
}

public class PngResource implements Resource<Png> {
    private final Png bytes;

    public PngResource(Png bytes) {
        this.bytes = Preconditions.checkNotNull(bytes);
    }

    @NonNull
    @Override
    public Class<Png> getResourceClass() {
        return Png.class;
    }

    @NonNull
    @Override
    public Png get() {
        return bytes;
    }

    @Override
    public int getSize() {
        return bytes.resource.length;
    }

    @Override
    public void recycle() {

    }
}

@GlideModule
public class SimpleGlideModule extends AppGlideModule {
    @RequiresApi(api = Build.VERSION_CODES.P)
    @Override
    public void registerComponents(@NonNull Context context, @NonNull Glide glide, @NonNull Registry registry) {
        super.registerComponents(context, glide, registry);
        registry.register(Bitmap.class, Png.class, new PngBitmapBytesTranscoder());
    }
    @Override
    public void applyOptions(Context context, GlideBuilder builder) {
      
    }

}

implementation 'com.github.bumptech.glide:glide:4.11.0'
annotationProcessor 'com.github.bumptech.glide:compiler:4.11.0'
 

调用方式

 private ImageView mIv2;

  Glide.with(mIv2)
                .as(Png.class)
.load("https://akatweb.mapfarm.com/arcgis/rest/services/BaseMapUpdate/MapServer/tile/7/56/102")
                .addListener(new RequestListener<Png>() {
                    @Override
                    public boolean onLoadFailed(@Nullable GlideException e, Object model, Target<Png> target, boolean isFirstResource) {
                        System.out.println("加载失败=======PNG====="+e);
                        return false;
                    }

                    @Override
                    public boolean onResourceReady(Png resource, Object model, Target<Png> target, DataSource dataSource, boolean isFirstResource) {
                        System.out.println("加载成功==========--PNG----==");
                        runOnUiThread(new Runnable() {
                            @Override
                            public void run() {
                                BitmapFactory.Options options1 = new BitmapFactory.Options();
//                                options1.inPreferredConfig = Bitmap.Config.ARGB_8888;
//                        options1.inPreferredConfig = Bitmap.Config.RGB_565;
//                                Bitmap bitmap1 = BitmapFactory.decodeByteArray(resource.resource, 0 , resource.resource.length, options1);
                                Bitmap bitmap1 = BitmapFactory.decodeByteArray(resource.resource, 0 , resource.resource.length);
                                mIv2.setImageBitmap(bitmap1);
                            }
                        });
                        return false;
                    }
                })
                .submit();

瓦片图是png格式,glide默认用jpg去转码,导致加载瓦片图透明区域变黑,如图所示,

image.png

问题,怎么能智能按需转换呢?比如瓦片图是jpg,就用jpg转换,瓦片图是png就用png转换~ 看glide看的头大