typedef NS_OPTIONS(NSUInteger, SDWebImageOptions) {

SDWebImageRetryFailed = 1 << 0,

SDWebImageLowPriority = 1 << 1,

SDWebImageCacheMemoryOnly = 1 << 2,

SDWebImageProgressiveDownload = 1 << 3,

SDWebImageRefreshCached = 1 << 4,

SDWebImageContinueInBackground = 1 << 5,

SDWebImageHandleCookies = 1 << 6,

SDWebImageAllowInvalidSSLCertificates = 1 << 7,

SDWebImageHighPriority = 1 << 8,

SDWebImageDelayPlaceholder = 1 << 9,

SDWebImageTransformAnimatedImage = 1 << 10,

SDWebImageAvoidAutoSetImage = 1 << 11

};
Copy the code

  • SDWebImageRetryFailed = 1 << 0,: By default, if a URL fails to download, the url is blacklisted and the library does not attempt to download again. This flag prevents the library from blacklisting the failed URL (simply if this flag is selected, even if a URL fails to download,sd) Webimage will try to download him again

  • SDWebImageLowPriority = 1 << 1,: By default, images are downloaded when the interaction is taking place (e.g., when you slide the TableView). This flag disables this feature, resulting in downloads only when the ScrollView slows down (i.e., when you slide the ScrollView does not download and you remove your hand from the screen) Crollview will only start downloading images when it starts slowing down

  • SDWebImageCacheMemoryOnly < < = 1, 2: this flag prohibits disk cache, only the memory cache

  • SDWebImageProgressiveDownload = 1 < < 3: this flag will display when images are downloaded (just like when you use to browse the web browser that images are downloaded, small cuttings of display (TBC))

  • SDWebImageRefreshCached = 1 << 4,: a cached image will still be rerequested. NSURLCache, not sdWebimage. URL, is used when images are updated

  • SDWebImageContinueInBackground = 1 < < 5, : starting background to download, join you into a page, there is a picture to download at this time you let the app in the background, the picture will continue to download (this is expected to be open backgroundfetch is useful)

  • SDWebImageHandleCookies = 1 << 6,: can control cookies that exist in NSHTTPCookieStore.

  • SDWebImageAllowInvalidSSLCertificates = 1 < < 7, : allow unsafe SSL certificates, careful in formal environment

  • SDWebImageHighPriority = 1 << 8,: by default, images are loaded in the order they are in the queue (fifO). This flag moves them to the front of the queue and loads them immediately, rather than waiting until the current queue loads.

  • SDWebImageDelayPlaceholder = 1 < < 9, : by default, the placeholder figure will display when the images are downloaded. This flag will delay the display of the placeholder image until the image is downloaded.

  • SDWebImageTransformAnimatedImage = 1 < < 10: whether the transform images