现有的项目是采用vue cli4.0脚手架生成的，现在想要引入typescript。
1.执行安装命令
npm install --save-dev typescript
npm install --save-dev @vue/cli-plugin-typescript
npm install --save-dev typescript
npm install --save-dev @vue/cli-plugin-typescript
2.根目录下新建 tsconfig.json
{
"compilerOptions": {
"target": "esnext",
"module": "esnext",
"strict": true,
"importHelpers": true,
"moduleResolution": "node",
"experimentalDecorators": true,
"esModuleInterop": true,
"allowSyntheticDefaultImports": true,
"sourceMap": true,
"baseUrl": ".",
"allowJs": false,
"noEmit": true,
"types": ["webpack-env"],
"paths": {

"@/*": ["src/*"]
},
"lib": ["esnext", "dom", "dom.iterable", "scripthost"]
},
"exclude": ["node_modules"]
}
{
"compilerOptions": {
"target": "esnext",
"module": "esnext",
"strict": true,
"importHelpers": true,
"moduleResolution": "node",
"experimentalDecorators": true,
"esModuleInterop": true,
"allowSyntheticDefaultImports": true,
"sourceMap": true,
"baseUrl": ".",
"allowJs": false,
"noEmit": true,
"types": ["webpack-env"],
"paths": {

"@/*": ["src/*"]
},
"lib": ["esnext", "dom", "dom.iterable", "scripthost"]
},
"exclude": ["node_modules"]
}
3.新增 shims-vue.d.ts
根目录下新建 shims-vue.d.ts，让 ts 识别 *.vue 文件，文件内容如下：
declare module '*.vue' {
import Vue from 'vue';
export default Vue;
}
declare module '*.vue' {
import Vue from 'vue';
export default Vue;
}
4.修改入口文件后缀
src/main.js => src/main.ts
src/main.js => src/main.ts
5.改造 .vue 文件
src/main.js => src/main.ts
src/main.js => src/main.ts
加上 lang=ts 可以让webpack识别此段代码为 typescript
6.使用装饰器插件
vue-class-component：强化 Vue 组件，使用 TypeScript装饰器 增强 Vue 组件，使得组件更加扁平化

vue-property-decorator：在 vue-class-component 上增强的结合 Vue 特性的装饰
Demo：
import { Vue, Component ,Watch} from 'vue-property-decorator';
@Component({
components: { Loading }
})
export default class App extends Vue{
old_back:object=null,
transitionName:string = "slide-right";
get ...mapState("base", ["loadingStatus"]);
@Watch('$route')
onChangeValue(to:object, from:object){

// console.log('$route', to, from)

const noBack = to.meta.noBack; // 监听路由变化时的状态为前进还是后退

// 去终节点左，从终节点过来右

if (to.meta.last) {

this.transitionName = "slide-left";

} else if (from.meta.last) {

this.transitionName = "slide-right";

} else if (from.meta.leaf) {

// 从其它叶子页面过来的，往右

this.transitionName = "slide-right";

} else {

if (noBack) {

// 去到不需要返回的界面往右

this.transitionName = "slide-right";

} else {

this.transitionName = "slide-left";

}

}
}
@Watch('loadingStatus')
onChangeValue(newVal: string){

if (newVal) {

setTimeout(_ => {

this.setLoading(false);

}, 1500);

}
}

// 弹出系统提示对话框
showAlert(msg:string) {

plus.nativeUI.alert(

msg,

function() {

// console.log("User pressed!");

},

"报警详情",

"确定"

);
}
}
import { Vue, Component ,Watch} from 'vue-property-decorator';
@Component({
components: { Loading }
})
export default class App extends Vue{
old_back:object=null,
transitionName:string = "slide-right";
get ...mapState("base", ["loadingStatus"]);
@Watch('$route')
onChangeValue(to:object, from:object){

// console.log('$route', to, from)

const noBack = to.meta.noBack; // 监听路由变化时的状态为前进还是后退

// 去终节点左，从终节点过来右

if (to.meta.last) {

this.transitionName = "slide-left";

} else if (from.meta.last) {

this.transitionName = "slide-right";

} else if (from.meta.leaf) {

// 从其它叶子页面过来的，往右

this.transitionName = "slide-right";

} else {

if (noBack) {

// 去到不需要返回的界面往右

this.transitionName = "slide-right";

} else {

this.transitionName = "slide-left";

}

}
}
@Watch('loadingStatus')
onChangeValue(newVal: string){

if (newVal) {

setTimeout(_ => {

this.setLoading(false);

}, 1500);

}
}

// 弹出系统提示对话框
showAlert(msg:string) {

plus.nativeUI.alert(

msg,

function() {

// console.log("User pressed!");

},

"报警详情",

"确定"

);
}
}