Android glide的使用场景(进阶篇)

之前有写过一篇关于glide的基本使用和相关配置，这篇就介绍一下glide在项目中通常会遇到的一些场景及解决方法

1. 当你项目中的头像地址是用前缀加用户ID拼接成的时，修改头像后，会发现头像还是你之前的头像，这时你可以不使用缓存加载图片，代码如下：

Glide.with(MyApplication.getContext())
                .load(url)
                .dontAnimate()
                .skipMemoryCache(true)
                .diskCacheStrategy(DiskCacheStrategy.NONE)
                .into(imageView);

2. 正确设置圆角图片

当布局文件中用到了自定义圆角控件时

Glide.with(MyApplication.getContext())
                .load(url)
                .asBitmap()
                .dontAnimate()
                .into(new SimpleTarget<Bitmap>() {
                    @Override
                    public void onResourceReady(Bitmap resource, GlideAnimation<? super Bitmap> glideAnimation) {
                        imageView.setImageBitmap(resource);
                    }
                });

没用到自定义圆角控件

Glide.with(MyApplication.getContext())
                .load(url)
                .asBitmap()
                .into(new BitmapImageViewTarget(imageView) {
                    @Override
                    protected void setResource(Bitmap resource) {
                        RoundedBitmapDrawable circularBitmapDrawable =
                                RoundedBitmapDrawableFactory.create(SSTApplication.getContext().getResources(), resource);
                        circularBitmapDrawable.setCircular(true);
                        imageView.setImageDrawable(circularBitmapDrawable);
                    }
                });

3. 加载大图出现OOM，可以控制高宽尺寸

Glide.with(MyApplication.getContext())
                .load(url)
                .override(180, 180)
                .into(imageView);

4. 第一次加载图片出现拉伸变形，可以设置取消动画解决

Glide.with(MyApplication.getContext()).load(url)
                .dontAnimate()
                .into(imageView);

5. 当设置placeholder图片的ScaleType和真实图片的ScaleType不一致时，这里巧妙的通过listener来处理，代码如下：

Glide.with(MyApplication.getContext()).load(url).dontAnimate()
                .listener(new SSTGlideRequestListener(imageView,ImageView.ScaleType.CENTER_INSIDE,ImageView.ScaleType.FIT_XY))
                .error(R.drawable.categore_def_icon)
                .placeholder(R.drawable.categore_def_icon).into(imageView);

static class SSTGlideRequestListener implements RequestListener<String, GlideDrawable> {
        private ImageView.ScaleType mPlaceScaleType;
        private ImageView.ScaleType mActualScaleType;
        private ImageView mImageView;

        SSTGlideRequestListener(ImageView mImageView, ImageView.ScaleType placeScaleType, ImageView.ScaleType actualScaleType){
            this.mPlaceScaleType = placeScaleType;
            this.mActualScaleType = actualScaleType;
            this.mImageView = mImageView;
            mImageView.setScaleType(placeScaleType);
        }
        @Override
        public boolean onException(Exception e, String model, Target<GlideDrawable> target, boolean isFirstResource) {
            mImageView.setScaleType(mPlaceScaleType);
            return false;
        }

        @Override
        public boolean onResourceReady(GlideDrawable resource, String model, Target<GlideDrawable> target, boolean isFromMemoryCache, boolean isFirstResource) {
            mImageView.setScaleType(mActualScaleType);
            return false;
        }
    }

6. 提前预下载好图片, 使用preload()方法

Glide.with(MyApplication.getContext())
                .load(url)
                .diskCacheStrategy(DiskCacheStrategy.ALL)
                .preload();

7. 当需要通过url获取缓存文件对象时

File localFile = DiskLruCacheWrapper.get(Glide.getPhotoCacheDir(SSTApplication.getContext()),
                DiskCache.Factory.DEFAULT_DISK_CACHE_SIZE).get(new OriginalKey(url, EmptySignature.obtain()));

static class OriginalKey implements Key {
        private final String id;
        private final Key signature;
        private OriginalKey(String id, Key signature) {
            this.id = id;
            this.signature = signature;
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) {
                return true;
            }
            if (o == null || getClass() != o.getClass()) {
                return false;
            }
            OriginalKey that = (OriginalKey) o;
            return id.equals(that.id) && signature.equals(that.signature);
        }

        @Override
        public int hashCode() {
            int result = id.hashCode();
            result = 31 * result + signature.hashCode();
            return result;
        }

        @Override
        public void updateDiskCacheKey(MessageDigest messageDigest) throws UnsupportedEncodingException {
            messageDigest.update(id.getBytes(STRING_CHARSET_NAME));
            signature.updateDiskCacheKey(messageDigest);
        }
    }

8.根据url判断图片是否下载

File localFile = DiskLruCacheWrapper.get(Glide.getPhotoCacheDir(SSTApplication.getContext()),
                DiskCache.Factory.DEFAULT_DISK_CACHE_SIZE).get(new OriginalKey(url, EmptySignature.obtain()));
return localFile!=null;

9. 清除当前url的缓存

File localFile = DiskLruCacheWrapper.get(Glide.getPhotoCacheDir(SSTApplication.getContext()),
                DiskCache.Factory.DEFAULT_DISK_CACHE_SIZE).get(new OriginalKey(url, EmptySignature.obtain()));
if(file != null)
      file.delete();

10.通过自定义View让Glide也可以实现Fresco的viewAspectRatio宽高比功能

public class SImageView extends AppCompatImageView {
    private float mAspectRatio = 0;
    public SImageView(Context context) {
        this(context,null);
    }

    public SImageView(Context context, @Nullable AttributeSet attrs) {
        this(context, attrs,0);
    }

    public SImageView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(attrs);
    }

    private void init(AttributeSet attrs) {
        final TypedArray typedArray = getContext().obtainStyledAttributes(attrs, R.styleable.SImageView);
        if(typedArray != null) {
            if (typedArray.hasValue(R.styleable.SImageView_viewAspectRatio)) {
                mAspectRatio = typedArray.getFloat(R.styleable.SImageView_viewAspectRatio,0);
            }
            typedArray.recycle();
        }
    }

    public void setAspectRatio(float aspectRatio){
        if(mAspectRatio != 0) {
            mAspectRatio = aspectRatio;
            requestLayout();
        }
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        if(mAspectRatio != 0) {
            int width = MeasureSpec.getSize(widthMeasureSpec);
            int height = (int) (width / mAspectRatio);
            heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);
        }
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }
}

attrs.xml

<declare-styleable name="SImageView">
      <attr name="viewAspectRatio" format="float"/>
</declare-styleable>

布局文件中只要在SImageView设置app:viewAspectRatio属性即可，
如：

<com.soaic.widget.SImageView
                android:id="@+id/image"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                app:viewAspectRatio="2"  />

OK， 以上就是我在项目中遇到的一些场景，希望对大家有所帮助！