简单实现即时聊天系统（包含Server、PC、Android、iOS、Web多端通讯）.zip

<p align="center" > <img src="https://raw.githubusercontent.com/SDWebImage/SDWebImage/master/SDWebImage_logo.png" title="SDWebImage logo" float=left> </p> [](https://travis-ci.org/SDWebImage/SDWebImage) [](http://cocoadocs.org/docsets/SDWebImage/) [](http://cocoadocs.org/docsets/SDWebImage/) [](https://www.apache.org/licenses/LICENSE-2.0.html) [](https://github.com/SDWebImage/SDWebImage) [](https://swift.org/package-manager/) [](https://developer.apple.com/documentation/xcode/creating_a_mac_version_of_your_ipad_app/) [](https://codecov.io/gh/SDWebImage/SDWebImage) This library provides an async image downloader with cache support. For convenience, we added categories for UI elements like `UIImageView`, `UIButton`, `MKAnnotationView`. ## Features - [x] Categories for `UIImageView`, `UIButton`, `MKAnnotationView` adding web image and cache management - [x] An asynchronous image downloader - [x] An asynchronous memory + disk image caching with automatic cache expiration handling - [x] A background image decompression to avoid frame rate drop - [x] [Progressive image loading](https://github.com/SDWebImage/SDWebImage/wiki/Advanced-Usage#progressive-animation) (including animated image, like GIF showing in Web browser) - [x] [Thumbnail image decoding](https://github.com/SDWebImage/SDWebImage/wiki/Advanced-Usage#thumbnail-decoding-550) to save CPU && Memory for large images - [x] [Extendable image coder](https://github.com/SDWebImage/SDWebImage/wiki/Advanced-Usage#custom-coder-420) to support massive image format, like WebP - [x] [Full-stack solution for animated images](https://github.com/SDWebImage/SDWebImage/wiki/Advanced-Usage#animated-image-50) which keep a balance between CPU && Memory - [x] [Customizable and composable transformations](https://github.com/SDWebImage/SDWebImage/wiki/Advanced-Usage#transformer-50) can be applied to the images right after download - [x] [Customizable and multiple caches system](https://github.com/SDWebImage/SDWebImage/wiki/Advanced-Usage#custom-cache-50) - [x] [Customizable and multiple loaders system](https://github.com/SDWebImage/SDWebImage/wiki/Advanced-Usage#custom-loader-50) to expand the capabilities, like [Photos Library](https://github.com/SDWebImage/SDWebImagePhotosPlugin) - [x] [Image loading indicators](https://github.com/SDWebImage/SDWebImage/wiki/How-to-use#use-view-indicator-50) - [x] [Image loading transition animation](https://github.com/SDWebImage/SDWebImage/wiki/Advanced-Usage#image-transition-430) - [x] A guarantee that the same URL won't be downloaded several times - [x] A guarantee that bogus URLs won't be retried again and again - [x] A guarantee that main thread will never be blocked - [x] Modern Objective-C and better Swift support - [x] Performances! ## Supported Image Formats - Image formats supported by Apple system (JPEG, PNG, TIFF, HEIC, ...), including GIF/APNG/HEIC animation - WebP format, including animated WebP (use the [SDWebImageWebPCoder](https://github.com/SDWebImage/SDWebImageWebPCoder) project) - Support extendable coder plugins for new image formats like BPG, AVIF. And vector format like PDF, SVG. See all the list in [Image coder plugin List](https://github.com/SDWebImage/SDWebImage/wiki/Coder-Plugin-List) ## Additional modules and Ecosystem In order to keep SDWebImage focused and limited to the core features, but also allow extensibility and custom behaviors, during the 5.0 refactoring we focused on modularizing the library. As such, we have moved/built new modules to [SDWebImage org](https://github.com/SDWebImage). #### SwiftUI [SwiftUI](https://developer.apple.com/xcode/swiftui/) is an innovative UI framework written in Swift to build user interfaces across all Apple platforms. We support SwiftUI by building a brand new framework called [SDWebImageSwiftUI](https://github.com/SDWebImage/SDWebImageSwiftUI), which is built on top of SDWebImage core functions (caching, loading and animation). The new framework introduce two View structs `WebImage` and `AnimatedImage` for SwiftUI world, `ImageIndicator` modifier for any View, `ImageManager` observable object for data source. Supports iOS 13+/macOS 10.15+/tvOS 13+/watchOS 6+ and Swift 5.1. Have a nice try and provide feedback! #### Coders for additional image formats - [SDWebImageWebPCoder](https://github.com/SDWebImage/SDWebImageWebPCoder) - coder for WebP format. Based on [libwebp](https://chromium.googlesource.com/webm/libwebp) - [SDWebImageHEIFCoder](https://github.com/SDWebImage/SDWebImageHEIFCoder) - coder for HEIF format, iOS 8+/macOS 10.10+ support. Based on [libheif](https://github.com/strukturag/libheif) - [SDWebImageBPGCoder](https://github.com/SDWebImage/SDWebImageBPGCoder) - coder for BPG format. Based on [libbpg](https://github.com/mirrorer/libbpg) - [SDWebImageFLIFCoder](https://github.com/SDWebImage/SDWebImageFLIFCoder) - coder for FLIF format. Based on [libflif](https://github.com/FLIF-hub/FLIF) - [SDWebImageAVIFCoder](https://github.com/SDWebImage/SDWebImageAVIFCoder) - coder for AVIF (AV1-based) format. Based on [libavif](https://github.com/AOMediaCodec/libavif) - [SDWebImagePDFCoder](https://github.com/SDWebImage/SDWebImagePDFCoder) - coder for PDF vector format. Using built-in frameworks - [SDWebImageSVGCoder](https://github.com/SDWebImage/SDWebImageSVGCoder) - coder for SVG vector format. Using built-in frameworks - [SDWebImageLottieCoder](https://github.com/SDWebImage/SDWebImageLottieCoder) - coder for Lottie animation format. Based on [rlottie](https://github.com/Samsung/rlottie) - and more from community! #### Custom Caches - [SDWebImageYYPlugin](https://github.com/SDWebImage/SDWebImageYYPlugin) - plugin to support caching images with [YYCache](https://github.com/ibireme/YYCache) - [SDWebImagePINPlugin](https://github.com/SDWebImage/SDWebImagePINPlugin) - plugin to support caching images with [PINCache](https://github.com/pinterest/PINCache) #### Custom Loaders - [SDWebImagePhotosPlugin](https://github.com/SDWebImage/SDWebImagePhotosPlugin) - plugin to support loading images from Photos (using `Photos.framework`) - [SDWebImageLinkPlugin](https://github.com/SDWebImage/SDWebImageLinkPlugin) - plugin to support loading images from rich link url, as well as `LPLinkView` (using `LinkPresentation.framework`) #### Integration with 3rd party libraries - [SDWebImageLottiePlugin](https://github.com/SDWebImage/SDWebImageLottiePlugin) - plugin to support [Lottie-iOS](https://github.com/airbnb/lottie-ios), vector animation rending with remote JSON files - [SDWebImageSVGKitPlugin](https://github.com/SDWebImage/SDWebImageLottiePlugin) - plugin to support [SVGKit](https://github.com/SVGKit/SVGKit), SVG rendering using Core Animation, iOS 8+/macOS 10.10+ support - [SDWebImageFLPlugin](https://github.com/SDWebImage/SDWebImageFLPlugin) - plugin to support [FLAnimatedImage](https://github.com/Flipboard/FLAnimatedImage) as the engine for animated GIFs - [SDWebImageYYPlugin](https://github.com/SDWebImage/SDWebImageYYPlugin) - plugin to integrate [YYImage](https://github.com/ibireme/YYImage) & [YYCache](https://github.com/ibireme/YYCache) for image rendering & caching #### Community driven popular libraries - [FirebaseUI](https://github.com/firebase/FirebaseUI-iOS) - Firebase Storage binding for query images, based on SDWebImage loader system - [react-nativ