Glide等比縮放圖片問題總結

前言

等比例縮放圖片在聊天列表中比較常見，而不是顯示固定寬高的圖片。最近對IM項目遷移到Androidx時，順便升級了glide,發現glide等比例縮放圖片出現bug(自定義ImageViewTarget實現圖片縮放),第一次能正常加載，第二次無法正常等比例縮放。原來項目是使用glide 3.7.0，現在是使用gilde 4.11.0 (4.10.0開始支持AndroidX)

解決方案

不同版本glide,ImageViewTarget使用差異如下:

glide 3.6.0

public class GlideRatioScaleTransForm extends ImageViewTarget<Bitmap> {

    private ImageView target;

    public GlideRatioScaleTransForm(ImageView target) {
        super(target);
        this.target = target;
    }

    @Override
    protected void setResource(Bitmap resource) {
        view.setImageBitmap(resource);

        int width = resource.getWidth();
        int height = resource.getHeight();

        //獲取imageView的寬
        int imageViewWidth = target.getWidth();

        //計算縮放比例
        float sy = (float) (imageViewWidth * 0.2) / (float) (width * 0.2);

        //計算圖片等比例放大後的高
        int imageViewHeight = (int) (height * sy);
        ViewGroup.LayoutParams params = target.getLayoutParams();
        params.height = imageViewHeight;
        target.setLayoutParams(params);
    }
}

glide 4.11.0

public class GlideRatioScaleTransForm extends ImageViewTarget<Bitmap> {

    public GlideRatioScaleTransForm(ImageView target) {
        super(target);
    }

    @Override
    protected void setResource(@Nullable Bitmap resource) {
        if (resource == null) {
            return;
        }
        view.setImageBitmap(resource);
        int width = resource.getWidth();
        int height = resource.getHeight();

        //獲取imageView的寬
        int imageViewWidth = view.getWidth();
        ViewGroup.LayoutParams params = view.getLayoutParams();
        if (imageViewWidth <=0){//修復等比例縮放bug
            imageViewWidth = params.width;
        }
        //計算縮放比例
        float sy = (float) (imageViewWidth * 0.2) / (float) (width * 0.2);
        //計算圖片等比例放大後的高
        int imageViewHeight = (int) (height * sy);
        params.height = imageViewHeight;
        view.setLayoutParams(params);
    }


}

使用

 <ImageView
        android:id="@+id/iv_img"
          android:layout_width="110dp"
          android:layout_height="110dp"
          />

//3.7.0
Glide.with(mContext)
                  .load(HttpConstant.SWIM_CHAT_BASE_URL + imageMessageBody.getUrl())
                  .asBitmap()
                  .placeholder(R.color.white)
                  .thumbnail(0.5f)//縮略圖
                  .diskCacheStrategy(DiskCacheStrategy.ALL)
                  .into(new GlideRatioScaleTransForm(iv_img));

 //4.11.0,asBitmap() 需要設置在 load(url)之前
 Glide.with(mContext)
         .asBitmap()
            .load(HttpConstant.SWIM_CHAT_BASE_URL + imageMessageBody.getUrl())
            .placeholder(R.color.white)
            .thumbnail(0.5f)//縮略圖
            .diskCacheStrategy(DiskCacheStrategy.ALL)
            .into(new GlideRatioScaleTransForm(iv_img));