android glide失败监听,Android 关于Glide的拓展(高斯模糊、加载监听、圆形图片)

关于Glide的加载监听，可以使用RequestListener接口实现。例如：

Glide.with(context)
        .load(imageUrl)
        .listener(new RequestListener<Drawable>() {
            @Override
            public boolean onLoadFailed(@Nullable GlideException e, Object model, Target<Drawable> target, boolean isFirstResource) {
                // 加载失败时的逻辑处理
                return false;
            }

            @Override
            public boolean onResourceReady(Drawable resource, Object model, Target<Drawable> target, DataSource dataSource, boolean isFirstResource) {
                // 加载成功时的逻辑处理
                return false;
            }
        })
        .into(imageView);

其中，onLoadFailed()方法在加载失败时被调用，返回值表示是否要继续展示占位图；onResourceReady()方法在加载成功时被调用，返回值同样表示是否要继续展示占位图。

关于Glide的拓展，可以使用Glide的Transformation接口实现。例如，实现高斯模糊：

public class BlurTransformation extends BitmapTransformation {
    private static final int MAX_RADIUS = 25;
    private static final int DEFAULT_DOWN_SAMPLING = 1;

    private Context context;
    private int radius;
    private int sampling;

    public BlurTransformation(Context context) {
        this(context, MAX_RADIUS, DEFAULT_DOWN_SAMPLING);
    }

    public BlurTransformation(Context context, int radius) {
        this(context, radius, DEFAULT_DOWN_SAMPLING);
    }

    public BlurTransformation(Context context, int radius, int sampling) {
        super();
        this.context = context;
        this.radius = radius;
        this.sampling = sampling;
    }

    @Override
    protected Bitmap transform(@NonNull BitmapPool pool, @NonNull Bitmap toTransform, int outWidth, int outHeight) {
        int width = toTransform.getWidth();
        int height = toTransform.getHeight();
        int scaledWidth = width / sampling;
        int scaledHeight = height / sampling;

        Bitmap bitmap = pool.get(scaledWidth, scaledHeight, Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(bitmap);
        canvas.scale(1 / (float) sampling, 1 / (float) sampling);
        Paint paint = new Paint();
        paint.setFlags(Paint.FILTER_BITMAP_FLAG);
        canvas.drawBitmap(toTransform, 0, 0, paint);

        bitmap = FastBlurUtil.doBlur(bitmap, radius, true);

        return bitmap;
    }

    @Override
    public void updateDiskCacheKey(@NonNull MessageDigest messageDigest) {
        messageDigest.update(("blur(" + radius + "," + sampling + ")").getBytes(CHARSET));
    }
}

其中，FastBlurUtil.doBlur()方法是自定义的快速高斯模糊算法，可以在GitHub上搜索相关的库。

还可以实现圆形图片：

public class CircleTransformation extends BitmapTransformation {
    public CircleTransformation(Context context) {
        super(context);
    }

    @Override
    protected Bitmap transform(@NonNull BitmapPool pool, @NonNull Bitmap toTransform, int outWidth, int outHeight) {
        int size = Math.min(toTransform.getWidth(), toTransform.getHeight());
        int x = (toTransform.getWidth() - size) / 2;
        int y = (toTransform.getHeight() - size) / 2;

        Bitmap squared = Bitmap.createBitmap(toTransform, x, y, size, size);
        Bitmap result = pool.get(size, size, Bitmap.Config.ARGB_8888);
        if (result == null) {
            result = Bitmap.createBitmap(size, size, Bitmap.Config.ARGB_8888);
        }

        Canvas canvas = new Canvas(result);
        Paint paint = new Paint();
        paint.setShader(new BitmapShader(squared, BitmapShader.TileMode.CLAMP, BitmapShader.TileMode.CLAMP));
        paint.setAntiAlias(true);

        float r = size / 2f;
        canvas.drawCircle(r, r, r, paint);

        return result;
    }

    @Override
    public String getId() {
        return getClass().getName();
    }
}

以上是一些Glide的拓展示例，可以根据需求进行修改和扩展。