使用TypeScript开发React Native应用示例教程

创建一个示例RN应用程序，从Expo的create-react-native-app（CRNA）开始，并将其配置为使用Typescript开发我们的RN代码。

1.使用CRNA创建React Native项目 $ yarn global add create-react-native-app

打开终端，并cd选择您的工作文件夹。运行以下命令以创建新的React Native项目：

create-react-native-app CRNAExpoTSExample

在此命令中，CRNA将为您构建一个非常基本但可立即运行的React Native应用程序。一旦应用程序创建，cd以创建应用程序的项目文件夹，并确保通过CRNA脚手架基本初始应用程序正在工作。

2.添加Typescript

安装依赖项

yarn add typescript tslint -D yarn add @types/react @types/react-native @types/react-dom -D

我们还需要rimraf和concurrently清理ts-transpiled-to-js文件的输出文件夹并同时运行npm脚本

yarn add concurrently rimraf -D 配置 tsc --init

tsconfig.json

在代码编辑器中打开项目并更新tsconfig.json为以下内容：

{ "compilerOptions": { "module":"es2015", "target": "es2015", "jsx": "react", "rootDir": "src", "outDir": "build", "allowSyntheticDefaultImports": true, "noImplicitAny": true, "sourceMap": true, "experimentalDecorators": true, "preserveConstEnums": true, "allowJs": true, "noUnusedLocals": true, "noUnusedParameters": true, "noImplicitReturns": true, "skipLibCheck": true, "moduleResolution":"Node" }, "filesGlob": [ "typings/index.d.ts", "src/**/*.ts", "src/**/*.tsx", "node_modules/typescript/lib/lib.es6.d.ts" ], "types": [ "react", "react-dom", "react-native" ], "exclude":[ "build", "node_modules", "jest.config.js", "App.js" ], "compileOnSave": false }

我们想将所有的Typescript应用程序代码文件存储在该src文件夹下的文件夹/子文件夹中。使用“rootDir”: “src ，Typescript编译器将查找文件夹及其子文件夹中的所有  文件.ts或  .tsx文件src。

“outDir”: “build”表示Typescript将在build文件夹下输出已转换的Javascript文件。

添加tslint.json

tslint.json在项目文件夹下添加文件，其内容如下：

{ "rules": { "member-access": false, "member-ordering": [ true, "public-before-private", "static-before-instance", "variables-before-functions" ], "no-any": false, "no-inferrable-types": [false], "no-internal-module": true, "no-var-requires": true, "typedef": [false], "typedef-whitespace": [ true, { "call-signature": "nospace", "index-signature": "nospace", "parameter": "nospace", "property-declaration": "nospace", "variable-declaration": "nospace" }, { "call-signature": "space", "index-signature": "space", "parameter": "space", "property-declaration": "space", "variable-declaration": "space" } ], "ban": false, "curly": false, "forin": true, "label-position": true, "no-arg": true, "no-bitwise": true, "no-conditional-assignment": true, "no-console": [ true, "debug", "info", "time", "timeEnd", "trace" ], "no-construct": true, "no-debugger": true, "no-duplicate-variable": true, "no-empty": true, "no-eval": true, "no-null-keyword": true, "no-shadowed-variable": true, "no-string-literal": true, "no-switch-case-fall-through": true, "no-unused-expression": true, "no-use-before-declare": true, "no-var-keyword": true, "radix": true, "switch-default": true, "triple-equals": [ true, "allow-undefined-check" ], "eofline": false, "indent": [ true, "spaces" ], "max-line-length": [ true, 150 ], "no-require-imports": false, "no-trailing-whitespace": true, "object-literal-sort-keys": false, "trailing-comma": [ true, { "multiline": "never", "singleline": "never" } ], "align": [true], "class-name": true, "comment-format": [ true, "check-space" ], "interface-name": [false], "jsdoc-format": true, "no-consecutive-blank-lines": [true], "no-parameter-properties": false, "one-line": [ true, "check-open-brace", "check-catch", "check-else", "check-finally", "check-whitespace" ], "quotemark": [ true, "single", "avoid-escape" ], "semicolon": [ true, "always", "ignore-interfaces" ], "variable-name": [ true, "allow-leading-underscore", "ban-keywords" ], "whitespace": [ true, "check-branch", "check-decl", "check-operator", "check-separator", "check-type" ] } } 创建src和build 文件夹

由于我们配置src和build为rootDir和outputDir中tsconfig.json，创建我们项目的根文件夹下这些文件夹。

当我们create-react-native-app CRNAExpoTSExample使用CRNA命令（）创建项目时，它在我们的项目文件夹下添加了一个App.js和App.test.js。这些文件移动到SRC我们创建的文件夹，然后重命名App.js，并App.test.js以App.tsx和App.test.tsx分别。

此时，您的项目文件夹和文件应如下所示：