android - 在缓存重新缩放的图像之前重新缩放在 Universal Image Loader 中下载的位图

Question

我正在使用 Universal Image Loader用于在 ImageView 中显示位图。但是当下载位图时，我想重新缩放它，然后应该缓存重新缩放的位图....我无法确定需要修改的那一点才能实现我的目的。

Answer 1

UIL DisplayImageOptions 有一个 imageScaleType 参数，它接受一个 ImageScaleType。 The docs for ImageScaleType明确缩放发生在图像被缓存之前:

/**
* Image will scaled-down exactly to target size (scaled width or height or both
* will be equal to target size; depends on ImageView's scale type). Use it if
* memory economy is critically important.
* Note: If original image size is smaller than target size then original image
* won't be scaled.
* 
* NOTE: For creating result Bitmap (of exact size) additional Bitmap will be
* created with Bitmap#createBitmap(...)
* Cons: Saves memory by keeping smaller Bitmap in memory cache (comparing with
* IN_SAMPLE... scale types)
* Pros: Requires more memory in one time for creation of result Bitmap.
*/

因此，在 DisplayOptions 中设置 ImageScaleType 并在缓存中享受缩放后的位图。