响应式

声明状态

Angular Renaissance 标志 Angular Renaissance

import { Component, signal } from "@angular/core";

@Component({
  selector: "app-name",
  template: `<h1>你好 {{ name() }}</h1>`,
})
export class NameComponent {
  name = signal("张三");
}

Vue 2 标志 Vue 2

<script>
export default {
  data() {
    return {
      name: "张三",
    };
  },
};
</script>

<template>
  <h1>你好 {{ name }}</h1>
</template>

更新状态

Angular Renaissance 标志 Angular Renaissance

import { Component, signal } from "@angular/core";

@Component({
  selector: "app-name",
  template: `<h1>你好 {{ name() }}</h1>`,
})
export class NameComponent {
  name = signal("张三");

  constructor() {
    this.name.set("李四");
  }
}

Vue 2 标志 Vue 2

<script>
export default {
  data() {
    return {
      name: "张三",
    };
  },
  created() {
    this.name = "李四";
  },
};
</script>

<template>
  <h1>你好 {{ name }}</h1>
</template>

计算属性

Angular Renaissance 标志 Angular Renaissance

import { Component, computed, signal } from "@angular/core";

@Component({
  selector: "app-double-count",
  template: `<div>{{ doubleCount() }}</div>`,
})
export class DoubleCountComponent {
  count = signal(10);

  doubleCount = computed(() => this.count() * 2);
}

Vue 2 标志 Vue 2

<script>
export default {
  data() {
    return {
      count: 10,
    };
  },
  computed: {
    doubleCount() {
      return this.count * 2;
    },
  },
};
</script>

<template>
  <div>{{ doubleCount }}</div>
</template>

模板语法

最简模板

Angular Renaissance 标志 Angular Renaissance

import { Component } from "@angular/core";

@Component({
  selector: "app-hello-world",
  template: `<h1>你好,世界</h1>`,
})
export class HelloWorldComponent {}

Vue 2 标志 Vue 2

<template>
  <h1>你好,世界</h1>
</template>

样式

Angular Renaissance 标志 Angular Renaissance

import { Component } from "@angular/core";

@Component({
  selector: "app-css-style",
  template: `
    <h1 class="title">我是红色的</h1>
    <button style="font-size: 10rem">我是一个按钮</button>
  `,
  styles: `
    .title {
      color: red;
    }
  `,
})
export class CssStyleComponent {}

Vue 2 标志 Vue 2

<template>
  <div>
    <h1 class="title">我是红色的</h1>
    <button style="font-size: 10rem">我是一个按钮</button>
  </div>
</template>

<style scoped>
.title {
  color: red;
}
</style>

DOM循环

Angular Renaissance 标志 Angular Renaissance

import { Component } from "@angular/core";

@Component({
  selector: "app-colors",
  template: `
    <ul>
      @for (color of colors; track color) {
        <li>{{ color }}</li>
      }
    </ul>
  `,
})
export class ColorsComponent {
  colors = ["红", "绿", "蓝"];
}

Vue 2 标志 Vue 2

<script>
export default {
  data() {
    return {
      colors: ["红", "绿", "蓝"],
    };
  },
};
</script>

<template>
  <ul>
    <li v-for="color in colors" :key="color">
      {{ color }}
    </li>
  </ul>
</template>

点击事件

Angular Renaissance 标志 Angular Renaissance

import { Component, signal } from "@angular/core";

@Component({
  selector: "app-counter",
  template: `
    <p>计数器: {{ count() }}</p>
    <button (click)="incrementCount()">+1</button>
  `,
})
export class CounterComponent {
  count = signal(0);

  incrementCount() {
    this.count.update((count) => count + 1);
  }
}

Vue 2 标志 Vue 2

<script>
export default {
  data() {
    return {
      count: 0,
    };
  },
  methods: {
    incrementCount() {
      this.count++;
    },
  },
};
</script>

<template>
  <div>
    <p>计数器: {{ count }}</p>
    <button @click="incrementCount">+1</button>
  </div>
</template>

DOM引用

Angular Renaissance 标志 Angular Renaissance

import {
  afterNextRender,
  Component,
  ElementRef,
  viewChild,
} from "@angular/core";

@Component({
  selector: "app-input-focused",
  template: `<input type="text" #inputRef />`,
})
export class InputFocusedComponent {
  inputRef = viewChild.required<ElementRef<HTMLInputElement>>("inputRef");

  constructor() {
    afterNextRender({ write: () => this.inputRef().nativeElement.focus() });
  }
}

Vue 2 标志 Vue 2

<script>
export default {
  mounted() {
    this.$refs.inputElement.focus();
  },
};
</script>

<template>
  <input ref="inputElement" />
</template>

条件渲染

Angular Renaissance 标志 Angular Renaissance

import { Component, computed, signal } from "@angular/core";

const TRAFFIC_LIGHTS = ["红灯", "黄灯", "绿灯"];

@Component({
  selector: "app-traffic-light",
  template: `
    <button (click)="nextLight()">下一个灯</button>
    <p>现在亮着的是: {{ light() }}</p>
    <p>
      你应该
      @switch (light()) {
        @case ("红灯") {
          <span>停下</span>
        }
        @case ("黄灯") {
          <span>慢行</span>
        }
        @case ("绿灯") {
          <span>赶紧走</span>
        }
      }
    </p>
  `,
})
export class TrafficLightComponent {
  lightIndex = signal(0);

  light = computed(() => TRAFFIC_LIGHTS[this.lightIndex()]);

  nextLight() {
    this.lightIndex.update((index) => (index + 1) % TRAFFIC_LIGHTS.length);
  }
}

Vue 2 标志 Vue 2

<script>
export default {
  data() {
    return {
      TRAFFIC_LIGHTS: ["红灯", "黄灯", "绿灯"],
      lightIndex: 0,
    };
  },
  computed: {
    light() {
      return this.TRAFFIC_LIGHTS[this.lightIndex];
    },
  },
  methods: {
    nextLight() {
      this.lightIndex = (this.lightIndex + 1) % this.TRAFFIC_LIGHTS.length;
    },
  },
};
</script>

<template>
  <div>
    <button @click="nextLight">下一个灯</button>
    <p>现在亮着的是: {{ light }}</p>
    <p>
      你应该
      <span v-if="light === '红灯'">停下</span>
      <span v-else-if="light === '黄灯'">慢行</span>
      <span v-else-if="light === '绿灯'">赶紧走</span>
    </p>
  </div>
</template>

生命周期

组件加载时

Angular Renaissance 标志 Angular Renaissance

import { Component, OnInit, signal } from "@angular/core";

@Component({
  selector: "app-page-title",
  template: `<p>页面标题: {{ pageTitle() }}</p>`,
})
export class PageTitleComponent implements OnInit {
  pageTitle = signal("");

  ngOnInit() {
    this.pageTitle.set(document.title);
  }
}

Vue 2 标志 Vue 2

<script>
export default {
  data() {
    return {
      pageTitle: "",
    };
  },
  mounted() {
    this.pageTitle = document.title;
  },
};
</script>

<template>
  <p>页面标题: {{ pageTitle }}</p>
</template>

组件卸载时

Angular Renaissance 标志 Angular Renaissance

import { Component, OnDestroy, signal } from "@angular/core";

@Component({
  selector: "app-time",
  template: `<p>当前时间: {{ time() }}</p>`,
})
export class TimeComponent implements OnDestroy {
  time = signal(new Date().toLocaleTimeString());

  timer = setInterval(
    () => this.time.set(new Date().toLocaleTimeString()),
    1000,
  );

  ngOnDestroy() {
    clearInterval(this.timer);
  }
}

Vue 2 标志 Vue 2

<script>
export default {
  data() {
    return {
      time: new Date().toLocaleTimeString(),
      timer: null,
    };
  },
  mounted() {
    this.timer = setInterval(() => {
      this.time = new Date().toLocaleTimeString();
    }, 1000);
  },
  beforeDestroy() {
    clearInterval(this.timer);
  },
};
</script>

<template>
  <p>当前时间: {{ time }}</p>
</template>

组件组合

组件Props传参

Angular Renaissance 标志 Angular Renaissance

import { Component } from "@angular/core";
import { UserprofileComponent } from "./userprofile.component";

@Component({
  selector: "app-root",
  imports: [UserprofileComponent],
  template: `
    <app-userprofile
      name="张三"
      [age]="20"
      [favouriteColors]="['green', 'blue', 'red']"
      [isAvailable]="true"
    />
  `,
})
export class AppComponent {}

Vue 2 标志 Vue 2

<script>
import UserProfile from "./UserProfile.vue";

export default {
  components: {
    UserProfile,
  },
};
</script>

<template>
  <UserProfile
    name="张三"
    :age="20"
    :favorite-colors="['green', 'blue', 'red']"
    is-available
  />
</template>

向父组件emit事件

Angular Renaissance 标志 Angular Renaissance

import { Component, signal } from "@angular/core";
import { AnswerButtonComponent } from "./answer-button.component";

@Component({
  selector: "app-root",
  imports: [AnswerButtonComponent],
  template: `
    <p>你快乐吗?</p>

    <app-answer-button (yes)="onAnswerYes()" (no)="onAnswerNo()" />

    <p style="font-size: 50px">{{ isHappy() ? "😀" : "😥" }}</p>
  `,
})
export class AppComponent {
  isHappy = signal(true);

  onAnswerYes() {
    this.isHappy.set(true);
  }

  onAnswerNo() {
    this.isHappy.set(false);
  }
}

Vue 2 标志 Vue 2

<script>
import AnswerButton from "./AnswerButton.vue";
export default {
  components: {
    AnswerButton,
  },
  data() {
    return {
      isHappy: true,
    };
  },
  methods: {
    onAnswerNo() {
      this.isHappy = false;
    },
    onAnswerYes() {
      this.isHappy = true;
    },
  },
};
</script>

<template>
  <div>
    <p>你快乐吗?</p>
    <AnswerButton @yes="onAnswerYes" @no="onAnswerNo" />
    <p style="font-size: 50px">
      {{ isHappy ? "😀" : "😥" }}
    </p>
  </div>
</template>

slot插槽

Angular Renaissance 标志 Angular Renaissance

import { Component } from "@angular/core";
import { FunnyButtonComponent } from "./funny-button.component";

@Component({
  selector: "app-root",
  imports: [FunnyButtonComponent],
  template: `<app-funny-button>点我!</app-funny-button>`,
})
export class AppComponent {}

Vue 2 标志 Vue 2

<script>
import FunnyButton from "./FunnyButton.vue";
export default {
  components: {
    FunnyButton,
  },
};
</script>

<template>
  <FunnyButton> 点我! </FunnyButton>
</template>

slot插槽内容

Angular Renaissance 标志 Angular Renaissance

import { Component } from "@angular/core";
import { FunnyButtonComponent } from "./funny-button.component";

@Component({
  selector: "app-root",
  imports: [FunnyButtonComponent],
  template: `
    <app-funny-button />

    <app-funny-button>这是传到slot的内容!</app-funny-button>
  `,
})
export class AppComponent {}

Vue 2 标志 Vue 2

<script>
import FunnyButton from "./FunnyButton.vue";
export default {
  components: {
    FunnyButton,
  },
};
</script>

<template>
  <div>
    <FunnyButton />
    <FunnyButton> 这是传到slot的内容! </FunnyButton>
  </div>
</template>

上下文

Angular Renaissance 标志 Angular Renaissance

import { Component, inject } from "@angular/core";
import { UserService } from "./user.service";
import { UserProfileComponent } from "./user-profile.component";

@Component({
  imports: [UserProfileComponent],
  providers: [UserService],
  selector: "app-root",
  template: `
    <h1>欢迎回来, {{ userService.user().username }}</h1>
    <app-user-profile />
  `,
})
export class AppComponent {
  protected userService = inject(UserService);
}

Vue 2 标志 Vue 2

<script>
import UserProfile from "./UserProfile.vue";

export default {
  components: { UserProfile },
  provide() {
    return {
      user: Object.assign(this.user, {
        updateUsername: this.updateUsername,
      }),
    };
  },
  data() {
    return {
      user: {
        id: 1,
        username: "abcdefg",
        email: "[email protected]",
      },
    };
  },
  methods: {
    updateUsername(newUsername) {
      this.user.username = newUsername;
    },
  },
};
</script>

<template>
  <div>
    <h1>欢迎回来, {{ user.username }}</h1>
    <UserProfile />
  </div>
</template>

表单输入

输入框

Angular Renaissance 标志 Angular Renaissance

import { Component, signal } from "@angular/core";
import { FormsModule } from "@angular/forms";

@Component({
  imports: [FormsModule],
  selector: "app-input-hello",
  template: `
    <p>{{ text() }}</p>
    <input [(ngModel)]="text" />
  `,
})
export class InputHelloComponent {
  text = signal("");
}

Vue 2 标志 Vue 2

<script>
export default {
  data() {
    return {
      text: "你好世界",
    };
  },
};
</script>

<template>
  <div>
    <p>{{ text }}</p>
    <input v-model="text" />
  </div>
</template>

复选框

Angular Renaissance 标志 Angular Renaissance

import { Component, signal } from "@angular/core";
import { FormsModule } from "@angular/forms";

@Component({
  imports: [FormsModule],
  selector: "app-is-available",
  template: `
    <input id="is-available" type="checkbox" [(ngModel)]="isAvailable" />
    <label for="is-available">这是一个checkbox</label>
  `,
})
export class IsAvailableComponent {
  isAvailable = signal(false);
}

Vue 2 标志 Vue 2

<script>
export default {
  data() {
    return {
      isAvailable: true,
    };
  },
};
</script>

<template>
  <div>
    <input id="is-available" v-model="isAvailable" type="checkbox" />
    <label for="is-available">这是一个checkbox</label>
  </div>
</template>

单选框

Angular Renaissance 标志 Angular Renaissance

import { Component, signal } from "@angular/core";
import { FormsModule } from "@angular/forms";

@Component({
  imports: [FormsModule],
  selector: "app-pick-pill",
  template: `
    <div>你选择了: {{ picked() }}</div>

    <input id="blue-pill" type="radio" value="blue" [(ngModel)]="picked" />
    <label for="blue-pill">蓝色</label>

    <input id="red-pill" type="radio" value="red" [(ngModel)]="picked" />
    <label for="red-pill">红色</label>
  `,
})
export class PickPillComponent {
  picked = signal("red");
}

Vue 2 标志 Vue 2

<script>
export default {
  data() {
    return {
      picked: "red",
    };
  },
};
</script>

<template>
  <div>
    <div>你选择了: {{ picked }}</div>

    <input id="blue-pill" v-model="picked" type="radio" value="blue" />
    <label for="blue-pill">蓝色</label>

    <input id="red-pill" v-model="picked" type="radio" value="red" />
    <label for="red-pill">红色</label>
  </div>
</template>

选择器

Angular Renaissance 标志 Angular Renaissance

import { Component, signal } from "@angular/core";
import { FormsModule } from "@angular/forms";

@Component({
  imports: [FormsModule],
  selector: "app-color-select",
  template: `
    <select [(ngModel)]="selectedColorId">
      @for (let color of colors; track color) {
        <option [value]="color.id" [disabled]="color.isDisabled">
          {{ color.text }}
        </option>
      }
    </select>
  `,
})
export class ColorSelectComponent {
  selectedColorId = signal(2);

  colors = [
    { id: 1, text: "红" },
    { id: 2, text: "蓝" },
    { id: 3, text: "绿" },
    { id: 4, text: "灰", isDisabled: true },
  ];
}

Vue 2 标志 Vue 2

<script>
export default {
  data() {
    return {
      selectedColorId: 2,
      colors: [
        { id: 1, text: "红" },
        { id: 2, text: "蓝" },
        { id: 3, text: "绿" },
        { id: 4, text: "灰", isDisabled: true },
      ],
    };
  },
};
</script>

<template>
  <select v-model="selectedColorId">
    <option
      v-for="color in colors"
      :key="color.id"
      :value="color.id"
      :disabled="color.isDisabled"
    >
      {{ color.text }}
    </option>
  </select>
</template>

Web应用特性

渲染应用

Angular Renaissance 标志 Angular Renaissance

<!doctype html>
<html>
  <body>
    <app-root></app-root>
  </body>
</html>

Vue 2 标志 Vue 2

<!doctype html>
<html>
  <body>
    <div id="app"></div>
    <script type="module" src="./main.js"></script>
  </body>
</html>

fetch获取数据

Angular Renaissance 标志 Angular Renaissance

import { Injectable } from "@angular/core";
import { httpResource } from "@angular/common/http";

@Injectable({ providedIn: "root" })
export class UserService {
  readonly usersResource = httpResource<UserResponse>(
    () => "https://randomuser.me/api/?results=3",
  );
}

export interface UserResponse {
  results: User[];
  info: any;
}

export interface User {
  name: {
    title: string;
    first: string;
    last: string;
  };
  picture: {
    large: string;
    medium: string;
    thumbnail: string;
  };
}

Vue 2 标志 Vue 2

<script>
export default {
  data() {
    return {
      isLoading: false,
      error: undefined,
      users: undefined,
    };
  },
  mounted() {
    this.fetchData();
  },
  methods: {
    async fetchData() {
      this.isLoading = true;
      try {
        const response = await fetch("https://randomuser.me/api/?results=3");
        const { results: users } = await response.json();
        this.users = users;
        this.error = undefined;
      } catch (error) {
        this.error = error;
      } finally {
        this.users = undefined;
        this.isLoading = false;
      }
    },
  },
};
</script>

<template>
  <p v-if="isLoading">正在获取用户信息……</p>
  <p v-else-if="error">获取用户信息出错</p>
  <ul v-else-if="users">
    <li v-for="user in users" :key="user.login.uuid">
      <img :src="user.picture.thumbnail" alt="user" />
      <p>
        {{ user.name.first }}
        {{ user.name.last }}
      </p>
    </li>
  </ul>
</template>