//檢查圖片是否存在 mycache能夠是圖片的地址 如url UIImage *myCachedImage = [[SDImageCache sharedImageCache] imageFromDiskCacheForKey:myCacheKey]; if (myCachedImage!=nil) { snapShotView.image=myCachedImage; }else{ //這裏下載圖片 而後緩存起來 [[SDImageCache sharedImageCache] storeImage:loadImage forKey:myCacheKey]; }