在vue项目中写Typescript

两种方式:

• extends写法(不使用装饰器) ---- 更贴近于vue语法

import Vue from 'vue'
import MainHeader from './header.vue'
import MainContent from './content.vue'

interface User {
  name: string,
  age: number
}

export default Vue.extend({
  components: {
    MainHeader,
    MainContent
  },
  props: {
    testProps: {
      type: Object as () => User
    }
  },
  data () {
    return {
      show: false
    }
  },
  methods: {
    setShow (state: boolean): void {
      this.show = state
    }
  },
  computed: {
    num(): number {
      return this.count
    },
    name: {
      // 需要标注有 `this` 参与运算的返回值类型
      get(): string {
        return this.item.n
      },
      set(val: string) {
        this.item.n = val
      }
    }
  }
})

• vue-property-decorator(装饰器语法) ---- 贴近类的写法

import { Vue, Component, Watch } from 'vue-property-decorator'
interface KeyValue {
  c: string
  n: string
}

@Component({
  components: {
    MainHeader,
    MainContent
  }
})
export default class Test extends Vue {
  // data
  count: number = 1
  item: KeyValue = {
    c: '',
    n: ''
  }

  // computed
  get num(): number {
    return this.count
  }
  get name(): string {
    return this.item.n
  }
  // 注意，这里不能标返回值类型，就算写void也不行
  set name(val: string) {
    this.item.n = val
  }

  // watch
  @Watch('count')
  watchCount(newVal: number, oldVal: number): void {
    console.log(newVal)
  }
  @Watch('item.n')
  watchName(newVal: string, oldVal: string): void {
    console.log(newVal)
  }
  @Watch('item', { deep: true })
  watchItem(newVal: KeyValue, oldVal: KeyValue): void {
    console.log(newVal)
  }
  // methods
  reset(): void {
    this.$emit('reset')
  },
  getKey(): string {
    return this.item.c
  }
}