问题：.ts文件识别不了.vue 文件？
main.ts
```
import Vue from "vue";
import Component from "vue-class-component";
import App from "./App.vue";
```
报这个错误
Cannot find module './App.vue' or its corresponding type declarations.
tsconfig.json
```
{ // 编译选项
  "compilerOptions": {
    // 编译输出目标 ES 版本
    "target": "esnext",
    // 采用的模块系统
    "module": "esnext",
    // 以严格模式解析
    "strict": false,
    "jsx": "preserve",
    // 从 tslib 导入外部帮助库: 比如__extends，__rest等
    "importHelpers": true,
    // 如何处理模块
    "moduleResolution": "node",
    // 启用装饰器
    "experimentalDecorators": true,
    "esModuleInterop": true,
    // 允许从没有设置默认导出的模块中默认导入
    "allowSyntheticDefaultImports": true,
    // 定义一个变量就必须给它一个初始值
    "strictPropertyInitialization" : false,
    // 允许编译javascript文件
    "allowJs": true,
    // 是否包含可以用于 debug 的 sourceMap
    "sourceMap": true,
    // 忽略 this 的类型检查, Raise error on this expressions with an implied any type.
    "noImplicitThis": false,
    // 解析非相对模块名的基准目录 
    "baseUrl": ".",
    // 给错误和消息设置样式，使用颜色和上下文。
    "pretty": true,
    // 设置引入的定义文件
    "types": ["webpack-env", "mocha", "chai"],
    // 指定特殊模块的路径
    "paths": {
      "@/*": ["src/*"]
    },
    // 编译过程中需要引入的库文件的列表
    "lib": ["esnext", "dom", "dom.iterable", "scripthost"],
    "typeRoots": [
      "./types",
      "./node_modules/vue/types",
      "./src"
    ],
  },
  // ts 管理的文件
  "include": [
    "src/**/*.ts",
    "src/**/*.tsx",
    "src/**/*.vue",
    "tests/**/*.ts",
    "tests/**/*.tsx"
  ],
  // ts 排除的文件
  "exclude": ["node_modules"]
}
```
shims-vue.d.ts
```
import Vue from "vue";
import VueRouter, { Route } from "vue-router";

declare module '*.vue' {
  export default Vue
}


declare module "vue/types/vue" {
  interface Vue {
    $router: VueRouter; // 这表示this下有这个东西
    $route: Route;
    $http: any;
    $Message: any;
    $Modal: any;
  }
}
```
第一次用ts写vue，不知道为什么报这个错误，
.vue文件里能识别.vue文件,.ts文件里就识别不了，但是页面能正常打开
package.json
```
{
  "name": "scgx",
  "version": "0.1.0",
  "private": true,
  "scripts": {
    "start": "vue-cli-service serve",
    "serve": "vue-cli-service serve",
    "build": "vue-cli-service build",
    "lint": "vue-cli-service lint",
    "test:unit": "vue-cli-service test:unit"
  },
  "dependencies": {
    "axios": "^0.18.0",
    "element-ui": "^2.13.2",
    "vue": "^2.6.6",
    "vue-class-component": "^6.0.0",
    "vue-property-decorator": "^7.0.0",
    "vue-router": "^3.0.1",
    "vuex": "^3.0.1"
  },
  "devDependencies": {
    "@types/chai": "^4.1.0",
    "@types/mocha": "^5.2.4",
    "@vue/cli-plugin-babel": "^3.5.0",
    "@vue/cli-plugin-eslint": "^3.5.0",
    "@vue/cli-plugin-typescript": "^3.5.0",
    "@vue/cli-plugin-unit-mocha": "^3.5.0",
    "@vue/cli-service": "^3.5.0",
    "@vue/eslint-config-prettier": "^4.0.1",
    "@vue/eslint-config-typescript": "^4.0.0",
    "@vue/test-utils": "1.0.0-beta.29",
    "babel-eslint": "^10.0.1",
    "babel-plugin-component": "^1.1.1",
    "chai": "^4.1.2",
    "eslint": "^5.8.0",
    "eslint-plugin-vue": "^5.0.0",
    "less": "^3.0.4",
    "less-loader": "^4.1.0",
    "typescript": "^3.2.1",
    "vue-template-compiler": "^2.5.21",
    "vuex-class": "^0.3.2"
  }
}
```
vue.config.js
```
const path = require("path");
const sourceMap = process.env.NODE_ENV === "development";

module.exports = {
  // 基本路径
  publicPath: "./",
  // 输出文件目录
  outputDir: "dist",
  // eslint-loader 是否在保存的时候检查
  lintOnSave: false,
  // webpack配置
  // see https://github.com/vuejs/vue-cli/blob/dev/docs/webpack.md
  chainWebpack: () => {},
  configureWebpack: config => {
    if (process.env.NODE_ENV === "production") {
      // 为生产环境修改配置...
      config.mode = "production";
    } else {
      // 为开发环境修改配置...
      config.mode = "development";
    }

    Object.assign(config, {
      // 开发生产共同配置
      resolve: {
        extensions: [".js", ".vue", ".json", ".ts", ".tsx"],
        alias: {
          vue$: "vue/dist/vue.js",
          "@": path.resolve(__dirname, "./src"),
          "@c": path.resolve(__dirname, "./src/components"),
          utils: path.resolve(__dirname, "./src/utils"),
          views: path.resolve(__dirname, "./src/views"),
          assets: path.resolve(__dirname, "./src/assets"),
          com: path.resolve(__dirname, "./src/components")
        }
      }
    });
  },
  // 生产环境是否生成 sourceMap 文件
  productionSourceMap: sourceMap,
  // css相关配置
  css: {
    // 是否使用css分离插件 ExtractTextPlugin
    extract: true,
    // 开启 CSS source maps?
    sourceMap: false,
    // css预设器配置项
    loaderOptions: {},
    // 启用 CSS modules for all css / pre-processor files.
    modules: false
  },
  // use thread-loader for babel & TS in production build
  // enabled by default if the machine has more than 1 cores
  parallel: require("os").cpus().length > 1,
  // PWA 插件相关配置
  // see https://github.com/vuejs/vue-cli/tree/dev/packages/%40vue/cli-plugin-pwa
  pwa: {},
  // webpack-dev-server 相关配置
  devServer: {
    open: process.platform === "darwin",
    host: "localhost",
    port: 3001, //8080,
    https: false,
    hotOnly: false,
    proxy: {
      // 设置代理
      // proxy all requests starting with /api to jsonplaceholder
      "/api": {
        target: "http://localhost:8989/",
        changeOrigin: true,
        ws: true,
        pathRewrite: {
          "^/api": ""
        }
      }
    },
    before: app => {}
  },
  // 第三方插件配置
  pluginOptions: {
    // ...
  }
};

```

回答：不要再shims-vue.d.ts中最外层使用import，使用这种写法
```
declare module '*.vue' {
  import Vue from 'vue';
  export default Vue;
}

declare module "vue/types/vue" {
  import VueRouter, { Route } from 'vue-router';
  interface Vue {
    $router: VueRouter; // 这表示this下有这个东西
    $route: Route;
    $http: any;
    $Message: any;
    $Modal: any;
  }
}
```

标签: typescript, vue.js