--- theme: cyanosis --- # 前言 `文章的图片链接都是在github上，可能需要...你懂得；本文含有大量关键步骤配置图片，强烈建议在合适环境下阅读` Flutter直接调用C层还是蛮有魅力，想想你练习C++，然后直接能用flutter在上层展示出效果，是不是就有大量练手的机会了，逻辑反手就用C++，Rust去写，给后面的接盘侠留下一座壮丽的克苏鲁神山，供其瞻仰上面只是开个玩笑，目前flutter ffi的交互，主要是为了和底层交互的统一，还能直接使用到大量宝藏一样的底层库目前ffi的同步调用还是比较可以，异步交互有办法去解决，但是使用起来比较麻烦 - 有兴趣的可以查看下面`异步消息通信`模块中贴的issue **Flutter和Rust的交互** - flutter_rust_bridge库给了一个很不错的解决方案 - 主要是他能很轻松的实现异步交互！本文是循序渐进式，比较全面的介绍了flutter的ffi使用，ffigen使用，最后才是`rust交互`介绍；如果对ffi和ffigen不太关心，也可直接阅读`rust交互`内容 # FFI交互方式 ## 配置 ### Android - 需要先配置ndk ```bash # mac ndk.dir=/Users/***/Develop/SDK/android_sdk/ndk/21.3.6528147 # windows ndk.dir=F:\\SDK\\AndroidSDK\\ndk\\21.3.6528147 ``` ![image-20220912112118631](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092309844.png) - 安装下CMake ![image-20220912120921839](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092309664.png) - 需要在Android的build.gradle里配置下cmake路径 ```groovy android { ... //配置CMakeList路径 externalNativeBuild { cmake { path "../lib/native/CMakeLists.txt" } } } ``` ![image-20220911224040763](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092310186.png) - 因为Windows和Linux都需要用到`CMakeLists.txt`，先来看下Android的配置 - Android的比较简单，配置下需要编译的c文件就行了 - 一个个添加文件的方式太麻烦了，这边直接用`native_batch`批量添加文件 - android会指定给定义的项目名上加上`lib`，`set(PROJECT_NAME "native_fun")`生成的名称应该为`libnative_fun.so` ```cmake # cmake_minimum_required 表示支持的 cmake 最小版本 cmake_minimum_required(VERSION 3.4.1) # 项目名称 set(PROJECT_NAME "native_fun") # 批量添加c文件 # add_library 关键字表示构建链接库，参数1是链接包名称; 参数2'SHARED'表示构建动态链接库; 参数2是源文件列表 file(GLOB_RECURSE native_batch ../../ios/Classes/native/*) add_library(${PROJECT_NAME} SHARED ${native_batch}) ``` 可以发现`file(GLOB_RECURSE native_batch ../../ios/Classes/native/*)`这边路径设置在iOS的Classes文件下，这边是为了方便统一编译native文件夹下的所有c文件，macOS和iOS需要放在Classes下，可以直接编译但是macOS和iOS没法指定编译超过父节点位置，必须放在Classes子文件夹下，超过这个节点就没法编译所以这边iOS和macOS必须要维护俩份相同c文件（建个文件夹吧，方便直接拷贝过去）；Android，Windows，Linux可以指定到这俩个中的其中之一（建议指定iOS的Classes，避免一些灵异Bug） - 效果 ![Sep-12-2022 18-02-58](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092310605.gif) ### iOS - iOS可以直接编译C文件，需要放在Classes文件夹下 ![image-20220911224706172](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092310630.png) - 效果 ![Sep-12-2022 18-02-58](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092311656.gif) ### macOS - macOS也可以直接编译C文件，需要放在Classes文件夹下 ![image-20220911225343151](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092311361.png) - 效果 ![Kapture 2022-09-12 at 18.11.00](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092311873.gif) ### Windows - windows下的CMakeLists.txt里面指定了lib/native下面的统一CMakeLists.txt配置 ```cmake # cmake_minimum_required 表示支持的 cmake 最小版本 cmake_minimum_required(VERSION 3.4.1) # 项目名称 set(PROJECT_NAME "libnative_fun") # 批量添加cpp文件 # add_library 关键字表示构建链接库，参数1是链接包名称; 参数2'SHARED'表示构建动态链接库; 参数2是源文件列表 file(GLOB_RECURSE native_batch ../../ios/Classes/native/*) add_library(${PROJECT_NAME} SHARED ${native_batch}) # Windows 需要把dll拷贝到bin目录 # 动态库的输出目录 set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/$<$:Debug>$<$:Release>") # 安装动态库的目标目录 set(INSTALL_BUNDLE_LIB_DIR "${CMAKE_INSTALL_PREFIX}") # 安装动态库，到执行目录 install(FILES "${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${PROJECT_NAME}.dll" DESTINATION "${INSTALL_BUNDLE_LIB_DIR}" COMPONENT Runtime) ``` ![image-20220911225730410](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092311056.png) - 这边可以将Android和Windows的配置统一下，加下判断即可 ```cmake # cmake_minimum_required 表示支持的 cmake 最小版本 cmake_minimum_required(VERSION 3.4.1) # 项目名称 if (WIN32) set(PROJECT_NAME "libnative_fun") else() set(PROJECT_NAME "native_fun") endif() # 批量添加c文件 # add_library 关键字表示构建链接库，参数1是链接包名称; 参数2'SHARED'表示构建动态链接库; 参数2是源文件列表 file(GLOB_RECURSE native_batch ../../ios/Classes/native/*) add_library(${PROJECT_NAME} SHARED ${native_batch}) # Windows 需要把dll拷贝到bin目录 if (WIN32) # 动态库的输出目录 set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/$<$:Debug>$<$:Release>") # 安装动态库的目标目录 set(INSTALL_BUNDLE_LIB_DIR "${CMAKE_INSTALL_PREFIX}") # 安装动态库，到执行目录 install(FILES "${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${PROJECT_NAME}.dll" DESTINATION "${INSTALL_BUNDLE_LIB_DIR}" COMPONENT Runtime) endif() ``` - 说明下，Windows这边必须将生成的dll拷贝到bin目录下，才能调用 - 所以cmake里面，最后那段Windows的特有代码是必须要写的 ![image-20220806185943415](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092311746.png) - 效果 ![windows](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092312175.gif) ## 交互 - 通用加载：NativeFFI.dynamicLibrary ```dart class NativeFFI { NativeFFI._(); static DynamicLibrary? _dyLib; static DynamicLibrary get dynamicLibrary { if (_dyLib != null) return _dyLib!; if (Platform.isMacOS || Platform.isIOS) { _dyLib = DynamicLibrary.process(); } else if (Platform.isAndroid) { _dyLib = DynamicLibrary.open('libnative_fun.so'); } else if (Platform.isWindows) { _dyLib = DynamicLibrary.open('libnative_fun.dll'); } else { throw Exception('DynamicLibrary初始化失败'); } return _dyLib!; } } ``` ### Flutter同步调用Native - dart ```dart /// 俩数相加 int ffiAddSyncInvoke(int a, int b) { final int Function(int x, int y) nativeAdd = NativeFFI.dynamicLibrary .lookup>("twoNumAdd") .asFunction(); return nativeAdd(a, b); } ``` - native ```cpp #include #ifdef WIN32 #define DART_API extern "C" __declspec(dllexport) #else #define DART_API extern "C" __attribute__((visibility("default"))) __attribute__((used)) #endif DART_API int32_t twoNumAdd(int32_t x, int32_t y){ return x + y; } ``` - 效果 ![windows](https://p3-juejin.byteimg.com/tos-cn-i-k3u1fbpfcp/1a6ad62184be4f30a40de9e8dd57b27f~tplv-k3u1fbpfcp-zoom-1.image) ### Native同步触发Flutter回调 - dart ```dart /// 传递的回调 typedef _NativeCallback = Int32 Function(Int32 num); /// Native方法 typedef _NativeSyncCallback = Void Function( Pointer> callback, ); /// Dart结束回调: Void和void不同,所以要区分开 typedef _DartSyncCallback = void Function( Pointer> callback, ); /// 必须使用顶层方法或者静态方法 /// macos端可以打印出native层日志, 移动端只能打印dart日志 int _syncCallback(int num) { print('--------'); return num; } /// 在native层打印回调传入的值 void ffiPrintSyncCallback() { final _DartSyncCallback dartSyncCallback = NativeFFI.dynamicLibrary .lookup>("nativeSyncCallback") .asFunction(); // 包装传递的回调 var syncFun = Pointer.fromFunction<_NativeCallback>(_syncCallback, 0); dartSyncCallback(syncFun); } ``` - native ```cpp #include #include #ifdef WIN32 #define DART_API extern "C" __declspec(dllexport) #else #define DART_API extern "C" __attribute__((visibility("default"))) __attribute__((used)) #endif using namespace std; // 定义传递的回调类型 typedef int32_t (*NativeCallback)(int32_t n); DART_API void nativeSyncCallback(NativeCallback callback) { // 打印 std::cout << "native log callback(666) = " << callback(666) << std::endl; } ``` - 效果 ![Kapture 2022-09-12 at 22.35.23](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092312722.gif) ### 异步消息通信 > 说明异步交互的写法有点复杂，可以查看下面的讨论 - https://github.com/dart-lang/sdk/issues/37022 - https://stackoverflow.com/questions/63311092/flutter-dart-how-to-use-async-callback-with-dart-ffi 异步通信需要导入额外c文件用作通信支持，但是如果你的iOS项目是swift项目，无法编译这些额外c文件 - 这些c文件我是封装在插件里，没想到办法怎么建立桥接 - 如果是OC项目，就可以直接编译目前来看 - Android和iOS可以编译额外的消息通信的c文件 - windows和macos试了，都没法编译，麻了 > 使用 - dart ```dart import 'dart:async'; import 'dart:ffi'; import 'dart:isolate'; import 'package:flutter/material.dart'; import 'package:flutter_ffi_toolkit/src/native_ffi.dart'; ReceivePort? _receivePort; StreamSubscription? _subscription; void _ensureNativeInitialized() { if (_receivePort == null) { WidgetsFlutterBinding.ensureInitialized(); final initializeApi = NativeFFI.dynamicLibrary.lookupFunction< IntPtr Function(Pointer), int Function(Pointer)>("InitDartApiDL"); if (initializeApi(NativeApi.initializeApiDLData) != 0) { throw "Failed to initialize Dart API"; } _receivePort = ReceivePort(); _subscription = _receivePort!.listen(_handleNativeMessage); final registerSendPort = NativeFFI.dynamicLibrary.lookupFunction< Void Function(Int64 sendPort), void Function(int sendPort)>('RegisterSendPort'); registerSendPort(_receivePort!.sendPort.nativePort); } } void _handleNativeMessage(dynamic address) { print('---------native端通信,地址: $address'); Pointer point = Pointer.fromAddress(address); print('---------native端通信,指针: $point'); dynamic data = point.cast(); print('---------native端通信,cast: $data'); } void ffiAsyncMessage(int a) { _ensureNativeInitialized(); final void Function(int x) asyncMessage = NativeFFI.dynamicLibrary .lookup>("NativeAsyncMessage") .asFunction(); asyncMessage(a); } void dispose() { // TODO _unregisterReceivePort(_receivePort.sendPort.nativePort); _subscription?.cancel(); _receivePort?.close(); } ``` - native ```cpp // C #include // Unix #include #include #include "dart_api/dart_api.h" #include "dart_api/dart_native_api.h" #include "dart_api/dart_api_dl.h" // Initialize `dart_api_dl.h` DART_EXPORT intptr_t InitDartApiDL(void* data) { return Dart_InitializeApiDL(data); } Dart_Port send_port_; DART_EXPORT void RegisterSendPort(Dart_Port send_port) { send_port_ = send_port; } void *thread_func(void *args) { printf("thread_func Running on (%p)\n", pthread_self()); sleep(2 /* seconds */); // doing something Dart_CObject dart_object; dart_object.type = Dart_CObject_kInt64; dart_object.value.as_int64 = reinterpret_cast(args); Dart_PostCObject_DL(send_port_, &dart_object); pthread_exit(args); } DART_EXPORT void NativeAsyncMessage(int32_t x) { printf("NativeAsyncCallback Running on (%p)\n", pthread_self()); pthread_t message_thread; pthread_create(&message_thread, NULL, thread_func, (void *)&x); } ``` - 额外c文件：https://github.com/xdd666t/flutter_ffi/tree/main/ffi_normal/ios/Classes/native/dart_api ![image-20220912222256653](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092312123.png) - 效果 ![Kapture 2022-09-12 at 22.39.37](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092312181.gif) # ffigen使用手写这些ffi交互代码，也是件比较麻烦的事，而且每个方法都要写对应的类型转换和相应的硬编码方法名，如果c的某个方法改变参数和方法名，再回去改对应的dart代码，无疑是一件蛋痛的事 flutter提供了一个自动生成ffi交互的代码，通俗的说：自动将c代码生成为对应dart的代码 ## 配置 - ubuntu/linux - 安装 libclangdev： `sudo apt-get install libclang-dev` - Windows - 安装 Visual Studio with C++ development support - 安装 [LLVM](https://releases.llvm.org/download.html)： `winget install -e --id LLVM.LLVM` - MacOS - 安装 Xcode - 安装 LLVM： `brew install llvm` - 引入ffigen - pub：https://pub.dev/packages/ffigen ```dart dependencies: ffigen: ^7.2.0 ffigen: # 输出生成的文件路径 output: 'lib/src/ffigen/two_num_add.dart' # 输出的类名 name: NativeLibrary headers: # 配置需要生成的文件 entry-points: - 'ios/Classes/native/ffigen/add.cpp' # 保证只转换two_num_add.cpp文件，不转换其包含的库文件，建议加上 include-directives: - 'ios/Classes/native/ffigen/add.cpp' ``` ## 生成文件 - 需要注意：生成的文件位置，需要和指定文件的编译位置保持一致，这样才能编译这些c文件 ![image-20221030230708385](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092314548.jpg) - ffigen生成命令 ```shell dart run ffigen ``` - add.cpp - 使用命令生成对应dart文件的时候，方法名前不能加我们定义的`DART_API`，不然无法生成对应dart文件 - 编译的时候必须要加上`DART_API`，不然无法编译该方法 - 有点无语，有知道能统一处理cpp文件方法的，还请在评论区告知呀 ```cpp #include #ifdef WIN32 #define DART_API extern "C" __declspec(dllexport) #else #define DART_API extern "C" __attribute__((visibility("default"))) __attribute__((used)) #endif // DART_API int32_t twoNumAddGen(int32_t x, int32_t y){ // return x + y; // } int32_t twoNumAddGen(int32_t x, int32_t y){ return x + y; } ``` - 生成的dart文件 ```dart // AUTO GENERATED FILE, DO NOT EDIT. // // Generated by `package:ffigen`. import 'dart:ffi' as ffi; class NativeLibrary { /// Holds the symbol lookup function. final ffi.Pointer Function(String symbolName) _lookup; /// The symbols are looked up in [dynamicLibrary]. NativeLibrary(ffi.DynamicLibrary dynamicLibrary) : _lookup = dynamicLibrary.lookup; /// The symbols are looked up with [lookup]. NativeLibrary.fromLookup( ffi.Pointer Function(String symbolName) lookup) : _lookup = lookup; int twoNumAddGen( int x, int y, ) { return _twoNumAddGen( x, y, ); } late final _twoNumAddGenPtr = _lookup>( 'twoNumAddGen'); late final _twoNumAddGen = _twoNumAddGenPtr.asFunction(); } ``` ![image-20221030230047893](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092315488.png) ## 使用 - 通用加载：NativeFFI.dynamicLibrary ```dart class NativeFFI { NativeFFI._(); static DynamicLibrary? _dyLib; static DynamicLibrary get dynamicLibrary { if (_dyLib != null) return _dyLib!; if (Platform.isMacOS || Platform.isIOS) { _dyLib = DynamicLibrary.process(); } else if (Platform.isAndroid) { _dyLib = DynamicLibrary.open('libnative_fun.so'); } else if (Platform.isWindows) { _dyLib = DynamicLibrary.open('libnative_fun.dll'); } else { throw Exception('DynamicLibrary初始化失败'); } return _dyLib!; } } ``` - 使用 ```dart NativeLibrary(NativeFFI.dynamicLibrary).twoNumAddGen(a, b); ``` - 效果 ![windows](https://p3-juejin.byteimg.com/tos-cn-i-k3u1fbpfcp/fc68b4e1ee094160b841076507d46955~tplv-k3u1fbpfcp-zoom-1.image) # rust 交互使用flutter_rust_bridge：[flutter_rust_bridge](https://github.com/fzyzcjy/flutter_rust_bridge) 下面全平台的配置，我成功编译运行后写的一份详细指南（踩了一堆坑），大家务必认真按照步骤配置~ 大家也可以参考官方文档，不过我觉得写的更加人性化，hhhhhh... - 原版：https://cjycode.com/flutter_rust_bridge/ - 中文版：https://trdthg.github.io/flutter_rust_bindgen_book_zh ## 准备 ### 创建Rust项目 - Rust安装：https://rustup.rs/ - 创建项目，请选择library ![image-20221127191621699](https://p3-juejin.byteimg.com/tos-cn-i-k3u1fbpfcp/0c9a85b6d0c241059b7a8126fb93d794~tplv-k3u1fbpfcp-zoom-1.image) - Cargo.toml 需要引入三个库：[package]和[lib]中的`name`参数，请保持一致，此处示例是`name = "rust_ffi"` - [lib]：crate-type =["lib", "staticlib", "cdylib"] - [build-dependencies]：flutter_rust_bridge_codegen - [dependencies]：flutter_rust_bridge - 最新版本查看：https://crates.io/ ```rust [package] name = "rust_ffi" version = "0.1.0" edition = "2021" [lib] name = "rust_ffi" crate-type = ["staticlib", "cdylib"] [build-dependencies] flutter_rust_bridge_codegen = "=1.51.0" [dependencies] flutter_rust_bridge = "=1.51.0" flutter_rust_bridge_macros = "=1.51.0" ``` - 写rust代码需要注意下，不要在lib.rs中写代码，不然生成文件无法获取导包 ![image-20221127194036971](https://p3-juejin.byteimg.com/tos-cn-i-k3u1fbpfcp/94f9489a4336466eafd79cdce1f5af70~tplv-k3u1fbpfcp-zoom-1.image) ### Flutter项目 - flutter项目正常创建就行了 ![image-20221127191323745](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092315282.png) - flutter的pubspec.yaml中需要添加这些库 ```dart dependencies: # https://pub.dev/packages/flutter_rust_bridge flutter_rust_bridge: 1.51.0 ffi: ^2.0.1 dev_dependencies: ffigen: ^7.0.0 ``` ### 命令 - 需要先安装下代码生成工具 ```bash # 必须 cargo install flutter_rust_bridge_codegen # iOS和macOS 必须需要 cargo install cargo-xcode ``` - 安装LLVM - ubuntu/linux - 安装 libclangdev： `sudo apt-get install libclang-dev` - Windows - 安装 Visual Studio with C++ development support - 安装 [LLVM](https://releases.llvm.org/download.html)： `winget install -e --id LLVM.LLVM` - MacOS - 安装 Xcode - 安装 LLVM： `brew install llvm` - 生成命令 ```bash flutter_rust_bridge_codegen -r rust/src/api.rs -d lib/ffi/rust_ffi/rust_ffi.dart ``` - 如果需要iOS和macOS，用下面的命令，说明请参照：配置 ---> iOS / macOS ```bash flutter_rust_bridge_codegen -r rust/src/api.rs -d lib/ffi/rust_ffi/rust_ffi.dart -c ios/Runner/bridge_generated.h -c macos/Runner/bridge_generated.h ``` - 请注意 - 如果你在flutter侧升级了`flutter_rust_bridge`版本 - rust的Cargo.toml也应该对`flutter_rust_bridge_codegen`和`flutter_rust_bridge`升级对应版本 - 升级完版本后需要重新跑下该命令 ```bash # 自动安装最新版本 cargo install flutter_rust_bridge_codegen # 指定版本 cargo install flutter_rust_bridge_codegen --version 1.51.0 --force ``` ## 配置 ### Android - 必须要安装`cargo-ndk` ：它能够将代码编译到适合的 JNI 而不需要额外的配置 ```bash cargo install cargo-ndk ``` - 添加cargo的android编译工具，在命令行执行下下述命令 ```bash rustup target add aarch64-linux-android rustup target add armv7-linux-androideabi rustup target add x86_64-linux-android rustup target add i686-linux-android ``` - NDK：请使用NDK 22或更早的版本，NDK下载请参考下图 ![image-20220912112118631](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092316181.png) - 需要在gradle.properties配置下 ```bash # mac ANDROID_NDK=/Users/***/Develop/SDK/android_sdk/ndk/21.3.6528147 # windows ANDROID_NDK=F:\\SDK\\AndroidSDK\\ndk\\21.3.6528147 ``` ![image-20221207221223355](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092316452.png) - 在 `android/app/build.gradle` 的最后添加下面几行 - ANDROID_NDK 就是在上面配置的变量 - "../../rust"：此处请配置自己rust项目文件夹命名 ```groovy [ new Tuple2('Debug', ''), new Tuple2('Profile', '--release'), new Tuple2('Release', '--release') ].each { def taskPostfix = it.first def profileMode = it.second tasks.whenTaskAdded { task -> if (task.name == "javaPreCompile$taskPostfix") { task.dependsOn "cargoBuild$taskPostfix" } } tasks.register("cargoBuild$taskPostfix", Exec) { // Until https://github.com/bbqsrc/cargo-ndk/pull/13 is merged, // this workaround is necessary. def ndk_command = """cargo ndk \ -t armeabi-v7a -t arm64-v8a -t x86_64 -t x86 \ -o ../android/app/src/main/jniLibs build $profileMode""" workingDir "../../rust" environment "ANDROID_NDK_HOME", "$ANDROID_NDK" if (org.gradle.nativeplatform.platform.internal.DefaultNativePlatform.currentOperatingSystem.isWindows()) { commandLine 'cmd', '/C', ndk_command } else { commandLine 'sh', '-c', ndk_command } } } ``` ### iOS - iOS 需要一些额外的交叉编译目标： ```bash # 64 bit targets (真机 & 模拟器): rustup target add aarch64-apple-ios x86_64-apple-ios # New simulator target for Xcode 12 and later rustup target add aarch64-apple-ios-sim ``` - 需要先生成子项目 ```bash # 在rust项目下执行该命令 cargo xcode ``` > **添加一些绑定文件** - 在 Xcode 中打开 `ios/Runner.xcodeproj`, 接着把 `$crate/$crate.xcodeproj` 添加为子项目：File ---> Add Files to "Runner" ![image-20221128213457207](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092316950.png) - 选择生成子项目，然后点击`add` ![image-20221128213836779](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092316563.png) - 选中那个文件夹，就会生成在哪个文件下 ![image-20221128214042835](https://p3-juejin.byteimg.com/tos-cn-i-k3u1fbpfcp/a0dadc51785e485aa41511192dce003e~tplv-k3u1fbpfcp-zoom-1.image) - 点击 `Runner` 根项目，TARGETS ---> Build Phases ---> Target Dependencies ：请添加 `$crate-staticlib` ![image-20221128221947641](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092316915.png) - 展开 Link Binary With Libraries：添加 `lib$crate_static.a` ![image-20221128222232489](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092316885.png) - 添加完毕后 ![image-20221128223107411](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092317944.png) > **绑定头文件** `flutter_rust_bridge_codegen` 会创建一个 C 头文件，里面列出了 Rust 库导出的所有符号，需要使用它，确保 Xcode 不会将符号去除。在项目中需要添加 `ios/Runner/bridge_generated.h` (或者 `macos/Runner/bridge_generated.h`) - 执行下述生成命令，会生成对应头文件，自动放到ios和macos目录下；可以封装成脚本，每次跑脚本就行了 ```bash flutter_rust_bridge_codegen -r rust/src/api.rs -d lib/ffi/rust_ffi/rust_ffi.dart -c ios/Runner/bridge_generated.h -c macos/Runner/bridge_generated.h ``` ![image-20221128224807766](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092317549.png) - 在 `ios/Runner/Runner-Bridging-Header.h` 中添加 ```diff #import "GeneratedPluginRegistrant.h" +#import "bridge_generated.h" ``` - `ios/Runner/AppDelegate.swift` 中添加 ```diff override func application( _ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]? ) -> Bool { + let dummy = dummy_method_to_enforce_bundling() + print(dummy) GeneratedPluginRegistrant.register(with: self) return super.application(application, didFinishLaunchingWithOptions: launchOptions) } ``` ### macOS > **说明** macos上面指向有个很奇怪的情况，官方文档说明的是需要链接`$crate-cdylib`，`$crate.dylib` ；但是链接这个库，用xcode编译可以执行，但是使用android studio直接编译执行的时候会报错 - 通过参考该库：https://github.com/Desdaemon/flutter_rust_bridge_template 与iOS保持一致，链接 `$crate-staticlib` ，`lib$crate_static.a` ，可以顺利执行下面配置，大家按需配置，我这边使用静态库能成功，链接动态库会失败 > **开始配置** - 需要先生成子项目，如果在配置iOS的时候已经执行了该命令，就不需要再次执行了（当然，再次执行也没问题） ```bash # 在rust项目下执行该命令 cargo xcode ``` - 在 Xcode 中打开 `macos/Runner.xcodeproj`, 接着把 `$crate/$crate.xcodeproj` 添加为子项目：File ---> Add Files to "Runner" ![image-20221128213457207](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092317787.png) - 点击 `Runner` 根项目，TARGETS ---> Build Phases ---> Target Dependencies ：请添加 `$crate-staticlib` (或者 $crate-staticlib ) ![image-20221204215117599](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092317814.png) - 展开 Link Binary With Libraries：添加 `lib$crate_static.a` (或者 `$crate.dylib` ) ![image-20221204215304940](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092317177.png) - 需要注意的是，如果使用了动态库，编译报找不到 `$crate.dylib`的时候 - 可以在`Link Binary With Libraries`的时候，macOS添加的**.dylib要选择`Optional` - 这个问题可能并不是必现 ![image-20221204183323089](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092317833.png) - Flutter 在 MacOS 上默认不使用符号，我们需要添加我们自己的 - 在 **Build Settings** 标签页中 - 把 **Objective-C Bridging Header** 设置为： `Runner/bridge_generated.h` ![image-20221204220901933](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092318473.png) - 还需要把`bridge_generated.h`文件加入macos项目 ![image-20221204215640724](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092318893.png) ![image-20221204215815410](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092319168.jpg) ![image-20221204215951922](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092319320.png) - `macos/Runner/AppDelegate.swift` 中添加 ```diff import Cocoa import FlutterMacOS @NSApplicationMain class AppDelegate: FlutterAppDelegate { override func applicationShouldTerminateAfterLastWindowClosed(_ sender: NSApplication) -> Bool { + dummy_method_to_enforce_bundling() return true } } ``` ### Windows / Linux > **说明** 目前使用`flutter_rust_bridge`等库保持在`1.51.0`版本 - 亲测在windows，android，ios，macos可以编译运行，linux（暂时没精力折腾）将`flutter_rust_bridge`更新到`1.54.0`版本 - 该版本有个比较大的改动，生成代码改动也比较大，需要安装最新版`flutter_rust_bridge_codegen`去生成代码 - 该版本在android，ios，macos可以编译运行，在windows上会报错 ```bash failed to run custom build command for `dart-sys v2.0.1` Microsoft.CppCommon.targets(247,5): error MSB8066 ``` 猜测是作者新版本`dart-sys v2.0.1`这个库有问题，导致编译产物路径出了问题，报错了上面的错目前本demo的版本号限制死在`1.51.0`版本；后面作者可能会解决该问题，需要使用新版本可自行尝试 - 在windows上安装编译生成库，需要安装指定版本 ```bash # 指定版本 cargo install flutter_rust_bridge_codegen --version 1.51.0 --force ``` > **重要说明** 因为windows上编译需要下载Corrosion，需要开启全局xx上网，不然可能在编译的时候，会存在无法下载Corrosion的报错推荐工具使用sstap 1.0.9.7版本，这个版本内置全局规则（可戴笠软件，不仅限浏览器），后面的版本该规则被删了 > **rust.make** - 需要先安装[Corrosion](https://github.com/corrosion-rs/corrosion) ，可参考：https://github.com/corrosion-rs/corrosion#installation - 需要安装cmake（选择安装到环境变量的方式）：https://cmake.org/download/ - 然后执行下述命令 ```bash git clone https://github.com/corrosion-rs/corrosion.git # Optionally, specify -DCMAKE_INSTALL_PREFIX=. You can install Corrosion anyway cmake -Scorrosion -Bbuild -DCMAKE_BUILD_TYPE=Release cmake --build build --config Release # This next step may require sudo or admin privileges if you're installing to a system location, # which is the default. cmake --install build --config Release ``` windows和linux需要添加个rust.make文件： - rust.make里面标注的内容需要和Cargo.toml里name保持一致 ![image-20221128220006292](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092319979.png) - rust.make ```cmake # We include Corrosion inline here, but ideally in a project with # many dependencies we would need to install Corrosion on the system. # See instructions on https://github.com/AndrewGaspar/corrosion#cmake-install # Once done, uncomment this line: # find_package(Corrosion REQUIRED) include(FetchContent) FetchContent_Declare( Corrosion GIT_REPOSITORY https://github.com/AndrewGaspar/corrosion.git GIT_TAG origin/master # Optionally specify a version tag or branch here ) FetchContent_MakeAvailable(Corrosion) corrosion_import_crate(MANIFEST_PATH ../rust/Cargo.toml CRATES rust_ffi) # Flutter-specific set(CRATE_NAME "rust_ffi") target_link_libraries(${BINARY_NAME} PRIVATE ${CRATE_NAME}) list(APPEND PLUGIN_BUNDLED_LIBRARIES $) ``` > **调整** - Windows：在`windows/CMakeLists.txt`添加rust.cmake文件 ```diff # Generated plugin build rules, which manage building the plugins and adding # them to the application. include(flutter/generated_plugins.cmake) +include(./rust.cmake) # === Installation === # Support files are copied into place next to the executable, so that it can ``` - Linux：在 Linux 上，你需要将 CMake 的最低版本升到 3.12，这是 [Corrosion](https://github.com/corrosion-rs/corrosion) 的要求，`rust.cmake` 依赖 Corrosion。需求修改 `linux/CMakeLists.txt` 的这一行 ```diff -cmake_minimum_required(VERSION 3.10) +cmake_minimum_required(VERSION 3.12) ... # Generated plugin build rules, which manage building the plugins and adding # them to the application. include(flutter/generated_plugins.cmake) +include(./rust.cmake) # === Installation === # By default, "installing" just makes a relocatable bundle in the build ``` ## 使用 - 调用 ```dart class NativeFFI { NativeFFI._(); static DynamicLibrary? _dyLib; static DynamicLibrary get dyLib { if (_dyLib != null) return _dyLib!; const base = 'rust_ffi'; if (Platform.isIOS) { _dyLib = DynamicLibrary.process(); } else if (Platform.isMacOS) { _dyLib = DynamicLibrary.executable(); } else if (Platform.isAndroid) { _dyLib = DynamicLibrary.open('lib$base.so'); } else if (Platform.isWindows) { _dyLib = DynamicLibrary.open('$base.dll'); } else { throw Exception('DynamicLibrary初始化失败'); } return _dyLib!; } } class NativeFun { static final _ffi = RustFfiImpl(NativeFFI.dyLib); static Future add(int left, int right) async { int sum = await _ffi.add(left: left, right: right); return sum; } } ``` - 自动生成的类就不写了，就是上面使用的RustFfiImpl ![image-20221204220434524](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212092320548.png) - 使用 ```dart void main() { runApp(const MyApp()); } class MyApp extends StatelessWidget { const MyApp({super.key}); @override Widget build(BuildContext context) { return const MaterialApp(title: 'Flutter Demo', home: MyHomePage()); } } class MyHomePage extends StatefulWidget { const MyHomePage({super.key}); @override State createState() => _MyHomePageState(); } class _MyHomePageState extends State { int _counter = 0; void _incrementCounter() async { _counter = await NativeFun.add(_counter, 2); setState(() {}); } @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar(title: const Text('Rust_Bridge Demo')), body: Center( child: Text( 'Count: $_counter', style: Theme.of(context).textTheme.headline4, ), ), floatingActionButton: FloatingActionButton( onPressed: _incrementCounter, tooltip: 'Increment', child: const Icon(Icons.add), ), ); } } ``` - 效果 ![rust_windows](https://raw.githubusercontent.com/xdd666t/MyData/master/pic/flutter/blog/202212111904861.gif) # 结语对于rust这块，这些配置确实有点麻烦，但是配置完，后面就不用管了痛苦一次就行了~.~ - 项目地址：https://github.com/xdd666t/flutter_ffi