# power_image **Repository Path**: mirrors_alibaba/power_image ## Basic Information - **Project Name**: power_image - **Description**: A powerful plugin that fully uses the native image library's ability to display images on the flutter side. - **Primary Language**: Unknown - **License**: MIT - **Default Branch**: main - **Homepage**: None - **GVP Project**: No ## Statistics - **Stars**: 0 - **Forks**: 0 - **Created**: 2022-06-16 - **Last Updated**: 2025-10-04 ## Categories & Tags **Categories**: Uncategorized **Tags**: None ## README # PowerImage 一个充分利用原生图片库能力、高扩展性的flutter图片库。 [English document](https://github.com/alibaba/power_image/blob/main/README.md) **特点：** - 支持加载 ui.Image 能力。在基于外接纹理的方案中，使用方无法拿到真正的 ui.Image 去使用，这导致图片库在这种特殊的使用场景下无能为力。 - 支持图片预加载能力。正如原生precacheImage一样。这在某些对图片展示速度要求较高的场景下非常有用。 - 新增纹理缓存，与原生图片库缓存打通！统一图片缓存，避免原生图片混用带来的内存问题。 - 支持模拟器。在 flutter-1.23.0-18.1.pre之前的版本，模拟器无法展示 Texture Widget。 - 完善自定义图片类型通道。解决业务自定义图片获取诉求。 - 完善的异常捕获与收集。 - 支持动图。（来自淘特的 PR） # 使用 ## 安装 - power_image：推荐使用最新版本，[power_image pub versions](https://pub.dev/packages/power_image/versions) - power_image_ext：你需要根据你使用的flutter版本来选择版本，[power_image_ext pub versions](https://pub.dev/packages/power_image_ext/versions) 将下方配置加入到 `pubspec.yaml` 文件中: ```yaml dependencies: power_image: 0.1.0-pre.2 dependency_overrides: power_image_ext: 2.5.3 ``` 或者直接引用 GitHub 源码： ```yaml dependencies: power_image: git: url: 'git@github.com:alibaba/power_image.git' ref: '0.1.0-pre.2' dependency_overrides: power_image_ext: git: url: 'git@github.com:alibaba/power_image_ext.git' ref: '2.5.3' ``` ## 初始化 ### Flutter #### 1. 用 `ImageCacheExt`替换 `ImageCache` . ```dart /// call before runApp() PowerImageBinding(); ``` or ```dart /// return ImageCacheExt in createImageCache(), /// if you have extends with WidgetsFlutterBinding class XXX extends WidgetsFlutterBinding { @override ImageCache createImageCache() { return ImageCacheExt(); } } ``` #### 2. 初始化 PowerImageLoader 初始化并设置全局的默认的渲染方式，renderingTypeTexture为texture方式，renderingTypeExternal为ffi方式 另外`PowerImageSetupOptions`里面也有异常上报，以及异常上报采样率。 ```dart PowerImageLoader.instance.setup(PowerImageSetupOptions(renderingTypeTexture, errorCallbackSamplingRate: 1.0, errorCallback: (PowerImageLoadException exception) { })); ``` ### iOS PowerImage 提供了基础的图片类型，包括网络图（network）、文件（file）、native 资源（nativeAsset）、flutter 资源（asset），使用方需要自定义对应的加载器。 #### OC ```objectivec [[PowerImageLoader sharedInstance] registerImageLoader:[PowerImageNetworkImageLoader new] forType:kPowerImageImageTypeNetwork]; [[PowerImageLoader sharedInstance] registerImageLoader:[PowerImageAssetsImageLoader new] forType:kPowerImageImageTypeNativeAsset]; [[PowerImageLoader sharedInstance] registerImageLoader:[PowerImageFlutterAssertImageLoader new] forType:kPowerImageImageTypeAsset]; [[PowerImageLoader sharedInstance] registerImageLoader:[PowerImageFileImageLoader new] forType:kPowerImageImageTypeFile]; ``` #### Swift ```swift PowerImageLoader.sharedInstance().register(PowerImageNetworkImageLoader.init(), forType: kPowerImageImageTypeNetwork) PowerImageLoader.sharedInstance().register(PowerImageAssetsImageLoader.init(), forType: kPowerImageImageTypeNativeAsset) PowerImageLoader.sharedInstance().register(PowerImageFlutterAssertImageLoader.init(), forType: kPowerImageImageTypeAsset) PowerImageLoader.sharedInstance().register(PowerImageFileImageLoader.init(), forType: kPowerImageImageTypeFile) ``` loader 需要遵循 PowerImageLoaderProtocol 协议： ```objectivec typedef void(^PowerImageLoaderCompletionBlock)(BOOL success, PowerImageResult *imageResult); @protocol PowerImageLoaderProtocol @required - (void)handleRequest:(PowerImageRequestConfig *)requestConfig completed:(PowerImageLoaderCompletionBlock)completedBlock; @end ``` Network image loader example: #### OC ```objectivec - (void)handleRequest:(PowerImageRequestConfig *)requestConfig completed:(PowerImageLoaderCompletionBlock)completedBlock { /// CDN optimization, you need transfer reqSize to native image loader! /// CDN optimization, you need transfer reqSize to native image loader! /// like this: [[SDWebImageManager sharedManager] downloadImageWithURL:[NSURL URLWithString:requestConfig.srcString] viewSize:reqSize completed: CGSize reqSize = requestConfig.originSize; /// attention. [[SDWebImageManager sharedManager] loadImageWithURL:[NSURL URLWithString:requestConfig.srcString] options:nil progress:^(NSInteger receivedSize, NSInteger expectedSize, NSURL * _Nullable targetURL) { } completed:^(UIImage * _Nullable image, NSData * _Nullable data, NSError * _Nullable error, SDImageCacheType cacheType, BOOL finished, NSURL * _Nullable imageURL) { if (image != nil) { completedBlock([PowerImageResult successWithImage:image]); }else { completedBlock([PowerImageResult failWithMessage:error.localizedDescription]); } }]; } ``` #### Swift ```swift func handleRequest(_ requestConfig: PowerImageRequestConfig!, completed completedBlock: PowerImageLoaderCompletionBlock!) { let reqSize:CGSize = requestConfig.originSize let url = URL(string: requestConfig.srcString()) SDWebImageManager.shared.loadImage(with: url, progress: nil) { image, data, error, cacheType, finished, url in if let image = image { if (image.sd_isAnimated) { let frames:[SDImageFrame] = SDImageCoderHelper.frames(from: image)! if frames.count > 0 { var arr:[PowerImageFrame] = [] for index in 0.. 1; --screenScale) { NSString *key = [self lookupKeyForAsset:[NSString stringWithFormat:@"%@/%d.0x/%@", path, screenScale, filename] fromPackage:package]; UIImage *image = [UIImage imageNamed:key inBundle:[NSBundle mainBundle] compatibleWithTraitCollection:nil]; if (image) { return image; } } NSString *key = [self lookupKeyForAsset:name fromPackage:package]; /// webp iOS < 14 not support if ([name hasSuffix:@".webp"] && !(@available(ios 14.0, *))) { NSString *mPath = [[NSBundle mainBundle] pathForResource:key ofType:nil]; NSData *webpData = [NSData dataWithContentsOfFile:mPath]; return [UIImage sd_imageWithWebPData:webpData]; } return [UIImage imageNamed:key inBundle:[NSBundle mainBundle] compatibleWithTraitCollection:nil]; } - (NSString *)lookupKeyForAsset:(NSString *)asset fromPackage:(NSString *)package { if (package && [package isKindOfClass:[NSString class]] && ![package isEqualToString:@""]) { return [FlutterDartProject lookupKeyForAsset:asset fromPackage:package]; }else { return [FlutterDartProject lookupKeyForAsset:asset]; } } ``` #### Swift ```swift func handleRequest(_ requestConfig: PowerImageRequestConfig!, completed completedBlock: PowerImageLoaderCompletionBlock!) { let image = self.flutterImage(requestConfig: requestConfig) if let image = image { completedBlock(PowerImageResult.success(with: image)) }else { completedBlock(PowerImageResult.fail(withMessage: "PowerImageFlutterAssertImageLoaderError")) } } private func flutterImage(requestConfig:PowerImageRequestConfig) -> UIImage? { let name:String = requestConfig.srcString()! let package:String? = requestConfig.src["package"] as? String let fileName:String = NSString(string: name).lastPathComponent let path:String = NSString(string: name).deletingLastPathComponent let scaleArr:[Int] = (2...Int(UIScreen.main.scale)).reversed() for scale in scaleArr { let key:String = self.lookupKeyForAsset(asset: String(format: "%s/%d.0x/%s", path,scale,fileName), package: package) let image = UIImage(named: key,in: Bundle.main,compatibleWith: nil) if image != nil { return image! } } let key = self.lookupKeyForAsset(asset: name, package: package) return UIImage(named: key,in: Bundle.main,compatibleWith: nil) } private func lookupKeyForAsset(asset:String,package:String?) -> String { if let package = package, package != "" { return FlutterDartProject.lookupKey(forAsset: asset,fromPackage: package) }else{ return FlutterDartProject.lookupKey(forAsset: asset) } } ``` file loader example: #### OC ```objectivec - (void)handleRequest:(PowerImageRequestConfig *)requestConfig completed:(PowerImageLoaderCompletionBlock)completedBlock { UIImage *image = [[UIImage alloc] initWithContentsOfFile:requestConfig.srcString]; if (image) { completedBlock([PowerImageResult successWithImage:image]); } else { completedBlock([PowerImageResult failWithMessage:@"UIImage initWithContentsOfFile nil"]); } } ``` #### Swift ```swift func handleRequest(_ requestConfig: PowerImageRequestConfig!, completed completedBlock: PowerImageLoaderCompletionBlock!) { let image = UIImage(contentsOfFile: requestConfig.srcString()) if let image = image { completedBlock(PowerImageResult.success(with: image)) }else{ completedBlock(PowerImageResult.fail(withMessage: "PowerImageFileImageLoaderError!")) } } ``` ### Android PowerImage 提供了基础的图片类型，包括网络图（network）、文件（file）、native 资源（nativeAsset）、flutter 资源（asset），使用方需要自定义对应的加载器。 #### Java ```java PowerImageLoader.getInstance().registerImageLoader( new PowerImageNetworkLoader(this.getApplicationContext()), "network"); PowerImageLoader.getInstance().registerImageLoader( new PowerImageNativeAssetLoader(this.getApplicationContext()), "nativeAsset"); PowerImageLoader.getInstance().registerImageLoader( new PowerImageFlutterAssetLoader(this.getApplicationContext()), "asset"); PowerImageLoader.getInstance().registerImageLoader( new PowerImageFileLoader(this.getApplicationContext()), "file"); ``` #### Kotlin ```kotlin PowerImageLoader.getInstance().registerImageLoader( PowerImageNetworkLoader(this.applicationContext), "network" ) PowerImageLoader.getInstance().registerImageLoader( PowerImageNativeAssetLoader(this.applicationContext), "nativeAsset" ) PowerImageLoader.getInstance().registerImageLoader( PowerImageFlutterAssetLoader(this.applicationContext), "asset" ) PowerImageLoader.getInstance().registerImageLoader( PowerImageFileLoader(this.applicationContext), "file" ) ``` loader 需要遵循 PowerImageLoaderProtocol 协议： ```java public interface PowerImageLoaderProtocol { void handleRequest(PowerImageRequestConfig request, PowerImageResult result); } ``` Network image loader example: #### Java ```java public class PowerImageNetworkLoader implements PowerImageLoaderProtocol { private Context context; public PowerImageNetworkLoader(Context context) { this.context = context; } @Override public void handleRequest(PowerImageRequestConfig request, PowerImageResponse response) { Glide.with(context).asDrawable().load(request.srcString()).listener(new RequestListener() { @Override public boolean onLoadFailed(@Nullable GlideException e, Object model, Target target, boolean isFirstResource) { response.onResult(PowerImageResult.genFailRet("Native加载失败: " + (e != null ? e.getMessage() : "null"))); return true; } @Override public boolean onResourceReady(Drawable resource, Object model, Target target, DataSource dataSource, boolean isFirstResource) { if (resource instanceof GifDrawable) { response.onResult(PowerImageResult.genSucRet(new GlideMultiFrameImage((GifDrawable) resource, false))); } else { if (resource instanceof BitmapDrawable) { response.onResult(PowerImageResult.genSucRet(new FlutterSingleFrameImage((BitmapDrawable) resource))); } else { response.onResult(PowerImageResult.genFailRet("Native加载失败: resource : " + String.valueOf(resource))); } } return true; } }).submit(request.width <= 0 ? Target.SIZE_ORIGINAL : request.width, request.height <= 0 ? Target.SIZE_ORIGINAL : request.height); } } ``` #### Kotlin ```kotlin class PowerImageNetworkLoader(private val context: Context) : PowerImageLoaderProtocol { override fun handleRequest(request: PowerImageRequestConfig, response: PowerImageResponse) { Glide.with(context).asDrawable().load(request.srcString()) .listener(object : RequestListener { override fun onLoadFailed( e: GlideException?, model: Any, target: Target, isFirstResource: Boolean ): Boolean { response.onResult(PowerImageResult.genFailRet("Native加载失败: " + if (e != null) e.message else "null")) return true } override fun onResourceReady( resource: Drawable, model: Any, target: Target, dataSource: DataSource, isFirstResource: Boolean ): Boolean { if (resource is GifDrawable) { response.onResult( PowerImageResult.genSucRet( GlideMultiFrameImage( resource as GifDrawable, false ) ) ) } else { if (resource is BitmapDrawable) { response.onResult( PowerImageResult.genSucRet( FlutterSingleFrameImage( resource as BitmapDrawable ) ) ) } else { response.onResult(PowerImageResult.genFailRet("Native加载失败: resource : $resource")) } } return true } }).submit( if (request.width <= 0) Target.SIZE_ORIGINAL else request.width, if (request.height <= 0) Target.SIZE_ORIGINAL else request.height ) } } ``` native asset loader example: #### Java ```java public class PowerImageNativeAssetLoader implements PowerImageLoaderProtocol { private Context context; public PowerImageNativeAssetLoader(Context context) { this.context = context; } @Override public void handleRequest(PowerImageRequestConfig request, PowerImageResponse response) { Resources resources = context.getResources(); int resourceId = 0; try { resourceId = resources.getIdentifier(request.srcString(), "drawable", context.getPackageName()); } catch (Resources.NotFoundException e) { // 资源未找到 e.printStackTrace(); } if (resourceId == 0) { response.onResult(PowerImageResult.genFailRet("资源未找到")); return; } Glide.with(context).asBitmap().load(resourceId).listener(new RequestListener() { @Override public boolean onLoadFailed(@Nullable GlideException e, Object model, Target target, boolean isFirstResource) { response.onResult(PowerImageResult.genFailRet("Native加载失败: " + (e != null ? e.getMessage() : "null"))); return true; } @Override public boolean onResourceReady(Bitmap resource, Object model, Target target, DataSource dataSource, boolean isFirstResource) { response.onResult(PowerImageResult.genSucRet(resource)); return true; } }).submit(request.width <= 0 ? Target.SIZE_ORIGINAL : request.width, request.height <= 0 ? Target.SIZE_ORIGINAL : request.height); } } ``` #### Kotlin ```kotlin class PowerImageNativeAssetLoader(private val context: Context) : PowerImageLoaderProtocol { override fun handleRequest(request: PowerImageRequestConfig, response: PowerImageResponse) { val resources = context.resources var resourceId = 0 try { resourceId = resources.getIdentifier( request.srcString(), "drawable", context.packageName ) } catch (e: Resources.NotFoundException) { // 资源未找到 e.printStackTrace() } if (resourceId == 0) { response.onResult(PowerImageResult.genFailRet("资源未找到")) return } Glide.with(context).asBitmap().load(resourceId).listener(object : RequestListener { override fun onLoadFailed( e: GlideException?, model: Any, target: Target, isFirstResource: Boolean ): Boolean { response.onResult(PowerImageResult.genFailRet("Native加载失败: " + if (e != null) e.message else "null")) return true } override fun onResourceReady( resource: Bitmap?, model: Any, target: Target, dataSource: DataSource, isFirstResource: Boolean ): Boolean { response.onResult(PowerImageResult.genSucRet(resource)) return true } }).submit( if (request.width <= 0) Target.SIZE_ORIGINAL else request.width, if (request.height <= 0) Target.SIZE_ORIGINAL else request.height ) } } ``` flutter asset loader example: #### Java ```java public class PowerImageFlutterAssetLoader implements PowerImageLoaderProtocol { private Context context; public PowerImageFlutterAssetLoader(Context context) { this.context = context; } @Override public void handleRequest(PowerImageRequestConfig request, PowerImageResponse response) { String name = request.srcString(); if (name == null || name.length() <= 0) { response.onResult(PowerImageResult.genFailRet("src 为空")); return; } String assetPackage = ""; if (request.src != null) { assetPackage = (String) request.src.get("package"); } String path; if (assetPackage != null && assetPackage.length() > 0) { path = FlutterMain.getLookupKeyForAsset(name, assetPackage); } else { path = FlutterMain.getLookupKeyForAsset(name); } if (path == null || path.length() <= 0) { response.onResult(PowerImageResult.genFailRet("path 为空")); return; } Uri asset = Uri.parse("file:///android_asset/" + path); Glide.with(context).asBitmap().load(asset).listener(new RequestListener() { @Override public boolean onLoadFailed(@Nullable GlideException e, Object model, Target target, boolean isFirstResource) { response.onResult(PowerImageResult.genFailRet("Native加载失败: " + (e != null ? e.getMessage() : "null"))); return true; } @Override public boolean onResourceReady(Bitmap resource, Object model, Target target, DataSource dataSource, boolean isFirstResource) { response.onResult(PowerImageResult.genSucRet(resource)); return true; } }).submit(request.width <= 0 ? Target.SIZE_ORIGINAL : request.width, request.height <= 0 ? Target.SIZE_ORIGINAL : request.height); } } ``` file loader example: #### Java ```java public class PowerImageFileLoader implements PowerImageLoaderProtocol { private final Context context; public PowerImageFileLoader(Context context) { this.context = context; } @Override public void handleRequest(PowerImageRequestConfig request, PowerImageResponse response) { String name = request.srcString(); if (name == null || name.length() <= 0) { response.onResult(PowerImageResult.genFailRet("src 为空")); return; } Uri asset = Uri.parse("file://" + name); Glide.with(context).asBitmap().load(asset).listener(new RequestListener() { @Override public boolean onLoadFailed(@Nullable GlideException e, Object model, Target target, boolean isFirstResource) { response.onResult(PowerImageResult.genFailRet("Native加载失败: " + (e != null ? e.getMessage() : "null"))); return true; } @Override public boolean onResourceReady(Bitmap resource, Object model, Target target, DataSource dataSource, boolean isFirstResource) { response.onResult(PowerImageResult.genSucRet(resource)); return true; } }).submit(request.width <= 0 ? Target.SIZE_ORIGINAL : request.width, request.height <= 0 ? Target.SIZE_ORIGINAL : request.height); } } ``` #### Kotlin ```kotlin class PowerImageFileLoader(private val context: Context) : PowerImageLoaderProtocol { override fun handleRequest(request: PowerImageRequestConfig, response: PowerImageResponse) { val name = request.srcString() if (name == null || name.length <= 0) { response.onResult(PowerImageResult.genFailRet("src 为空")) return } val asset = Uri.parse("file://$name") Glide.with(context).asBitmap().load(asset).listener(object : RequestListener { override fun onLoadFailed( e: GlideException?, model: Any, target: Target, isFirstResource: Boolean ): Boolean { response.onResult(PowerImageResult.genFailRet("Native加载失败: " + if (e != null) e.message else "null")) return true } override fun onResourceReady( resource: Bitmap?, model: Any, target: Target, dataSource: DataSource, isFirstResource: Boolean ): Boolean { response.onResult(PowerImageResult.genSucRet(resource)) return true } }).submit( if (request.width <= 0) Target.SIZE_ORIGINAL else request.width, if (request.height <= 0) Target.SIZE_ORIGINAL else request.height ) } } ``` ## API network image: ```dart PowerImage.network( String src, { Key? key, String? renderingType, double? imageWidth, double? imageHeight, this.width, this.height, this.frameBuilder, this.errorBuilder, this.fit = BoxFit.cover, this.alignment = Alignment.center, this.semanticLabel, this.excludeFromSemantics = false, }) ``` nativeAsset: ```dart PowerImage.nativeAsset( String src, { Key? key, String? renderingType, double? imageWidth, double? imageHeight, this.width, this.height, this.frameBuilder, this.errorBuilder, this.fit = BoxFit.cover, this.alignment = Alignment.center, this.semanticLabel, this.excludeFromSemantics = false, }) ``` Flutter asset: ```dart PowerImage.asset( String src, { Key? key, String? renderingType, double? imageWidth, double? imageHeight, String? package, this.width, this.height, this.frameBuilder, this.errorBuilder, this.fit = BoxFit.cover, this.alignment = Alignment.center, this.semanticLabel, this.excludeFromSemantics = false, }) ``` File: ```dart PowerImage.file(String src, {Key key, this.width, this.height, this.frameBuilder, this.errorBuilder, this.fit = BoxFit.cover, this.alignment = Alignment.center, String renderingType, double imageWidth, double imageHeight}) ``` 自定义来源图片: 1.自定义 imageType，比如 “album”。 2.自定义 src（PowerImageRequestOptionsSrc），里面放需要传递给native的自定义参数。 3.Native侧自定义Loader，接收Flutter侧传递的参数，然后返回一个Bitmap或UIImage，并注册该Loader。 4.Flutter侧就可以展示自定义的图片了。 ```dart /// 自定义 imageType\src /// 效果：将src encode 后，完成地传递给 native 对应 imageType 注册的 loader /// 使用场景： /// 例如，自定义加载相册照片，通过自定义 imageType 为 "album"， /// native 侧注册 "album" 类型的 loader 自定义图片的加载。 PowerImage.type( String imageType, { required PowerImageRequestOptionsSrc src, Key? key, String? renderingType, double? imageWidth, double? imageHeight, this.width, this.height, this.frameBuilder, this.errorBuilder, this.fit = BoxFit.cover, this.alignment = Alignment.center, this.semanticLabel, this.excludeFromSemantics = false, }) ``` .options ```dart /// 更加灵活的方式，通过自定义options来展示图片 /// /// PowerImageRequestOptions({ /// @required this.src, //资源 /// @required this.imageType, //资源类型，如网络图，本地图或者自定义等 /// this.renderingType, //渲染方式，默认全局 /// this.imageWidth, //图片的渲染的宽度 /// this.imageHeight, //图片渲染的高度 /// }); /// /// PowerExternalImageProvider（FFI[bitmap]方案） /// PowerTextureImageProvider（texture方案） /// /// 使用场景： /// 例如，自定义加载相册照片，通过自定义 imageType 为 "album"， /// native 侧注册 "album" 类型的 loader 自定义图片的加载。 /// PowerImage.options( PowerImageRequestOptions options, { Key? key, this.width, this.height, this.frameBuilder, this.errorBuilder, this.fit = BoxFit.cover, this.alignment = Alignment.center, this.semanticLabel, this.excludeFromSemantics = false, }) ``` #### Android ```java PowerImageLoader.getInstance().registerImageLoader( new PowerImageAlbumLoader(application.getApplicationContext()), "album"); ``` ```java public class PowerImageAlbumLoader implements PowerImageLoaderProtocol { private final Context context; public PowerImageAlbumLoader(Context context) { this.context = context; } @Override public void handleRequest(PowerImageRequestConfig request, final PowerImageResponse response) { Map src = request.src; if (src == null || src.get(Const.Argument.ASSET_ID) == null || src.get(Const.Argument.ASSET_TYPE) == null) { PowerImageResult result = PowerImageResult.genFailRet("asset id or assetType == null"); response.onResult(result); return; } AssetQuality quality = AssetQuality.values()[(int) src.get(Const.Argument.QUALITY)]; boolean highQuality = quality == AssetQuality.fullScreen; final LocalMedia media = new LocalMedia(); media.fromMap(src); final ThumbnailLoader thumbnailLoader = new ThumbnailLoader(context); thumbnailLoader.load(media, highQuality, new ThumbnailLoader.ThumbnailLoadListener() { @Override public void onThumbnailLoaded(final Bitmap bitmap) { PowerImageResult result; if (bitmap == null) { result = PowerImageResult.genFailRet("bitmap == null"); } else { result = PowerImageResult.genSucRet(bitmap); } response.onResult(result); } }); } } ``` #### iOS ```objective-c [[PowerImageLoader sharedInstance] registerImageLoader:[AlbumAssetsImageLoader new] forType:@"album"]; ``` ```objective-c - (void)handleRequest:(PowerImageRequestConfig *)requestConfig completed:(PowerImageLoaderCompletionBlock)completedBlock { NSString *assetId = requestConfig.src[@"assetId"]; NSNumber *imageWidth = requestConfig.src[@"imageWidth"]; NSNumber *imageHeight = requestConfig.src[@"imageHeight"]; if (assetId) { if (imageWidth && imageHeight) { [[MPAssetManager sharedInstance] getImageWithAssetId:assetId imageSize:CGSizeMake(imageWidth.doubleValue, imageHeight.doubleValue) successHandler:^(UIImage *image) { completedBlock([PowerImageResult successWithImage:image]); } failureHandler:^(NSError *error) { completedBlock([PowerImageResult failWithMessage:error.localizedDescription]); }]; } else { [[MPAssetManager sharedInstance] getThumbnail:assetId successHandler:^(UIImage *image) { completedBlock([PowerImageResult successWithImage:image]); } failureHandler:^(NSError *error) { completedBlock([PowerImageResult failWithMessage:error.localizedDescription]); }]; } } else { completedBlock([PowerImageResult failWithMessage:@"assetId is nil"]); } } ``` # 例子 Network ```dart return PowerImage.network( 'https://flutter.github.io/assets-for-api-docs/assets/widgets/owl.jpg', width: 100, height: 100, ); ``` # 最佳实践 [最佳实践](BESTPRACTICE.md) # 原理 https://mp.weixin.qq.com/s/TdTGK21S-Yd3aD-yZDoYyQ