TypeScript 创建单页天气查询应用程序

【这是我参与8月更文挑战的第 20 天，活动详情查看：8月更文挑战】

关于 TypeScript 是什么，可以在掘金找到很多文章，如想学习一下TypeScript，GitHub是个不错的平台，在文章《收藏GitHub上的7个热门TypeScript项目》介绍几个不错的开源项目。本文将使用TypeScript创建单页应用程序（SPA）示例，天气查询。

准备工作

要完成示例项目，需要在安装 Node.js 和 Angular CLI（一个用于 Angular 的命令行接口）：

安装 Node.js：

[下载](https://nodejs.org/en/)适合的版本，选择默认选项来完成安装。

命令行运行 `node -v` 来验证版本号，当前最新版本为 v10.13.0。

安装 Angular CLI：
1. 运行 npm install -g angular-cli 进行安装
2. 成功完成安装后，命令行运行 ng -v，查看 CLI 版本号

创建基础应用程序和模块

创建一个 Angular 项目

运行下面的命令来生成一个新 Angular 项目（其中 quintion-ng-app 是项目名称）：

ng new quintion-ng-app --skip-git

安装所有需要的包和 Angular 基础应用程序，项目结构如下：

qzcloud-ng-app/src 目录的内容包括：

运行应用程序:

ng serve

默认情况下，进程在端口 4200 上启动。可以运行 ng serve --port 4206 命令来指定运行端口号。

打开浏览器并输入http://localhost:4206/。运行结果如图，这表明应用程序已启动、运行并准备就绪。对项目代码的任何修改都将自动重新启动项目。

将模块组件代码

在片段1中，第 16 行显示了 AppModule 模块的声明。

片段1：src/app/app.module.ts：

此处代码为项目创建时自动生成的。

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';

import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    AppRoutingModule
  ],
  providers: [],
  bootstrap: [AppComponent]   //启动组件
})
export class AppModule { }

此模块仅包含一个组件AppComponent

组件内部结构

片段2为 src/app/app.component.ts 文件中的主要应用程序组件的内容。

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

@Component({ selector: 'app-root', templateUrl: './app.component.html', styleUrls: ['./app.component.scss'] })
export class AppComponent {
  title = 'quintion-ng-app';
}

这是 app.component.html 文件中的主要应用程序组件的内容：

<!-- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * -->
<!-- * * * * * * * * * * * The content below * * * * * * * * * * * -->
<!-- * * * * * * * * * * is only a placeholder * * * * * * * * * * -->
<!-- * * * * * * * * * * and can be replaced. * * * * * * * * * * * -->
<!-- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * -->
<!-- * * * * * * * * * Delete the template below * * * * * * * * * * -->
<!-- * * * * * * * to get started with your project! * * * * * * * * -->
<!-- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * -->

<style> :host { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol"; font-size: 14px; color: #333; box-sizing: border-box; -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; } h1, h2, h3, h4, h5, h6 { margin: 8px 0; } p { margin: 0; } .spacer { flex: 1; } .toolbar { position: absolute; top: 0; left: 0; right: 0; height: 60px; display: flex; align-items: center; background-color: #1976d2; color: white; font-weight: 600; } .toolbar img { margin: 0 16px; } .toolbar #twitter-logo { height: 40px; margin: 0 16px; } .toolbar #twitter-logo:hover { opacity: 0.8; } .content { display: flex; margin: 82px auto 32px; padding: 0 16px; max-width: 960px; flex-direction: column; align-items: center; } svg.material-icons { height: 24px; width: auto; } svg.material-icons:not(:last-child) { margin-right: 8px; } .card svg.material-icons path { fill: #888; } .card-container { display: flex; flex-wrap: wrap; justify-content: center; margin-top: 16px; } .card { border-radius: 4px; border: 1px solid #eee; background-color: #fafafa; height: 40px; width: 200px; margin: 0 8px 16px; padding: 16px; display: flex; flex-direction: row; justify-content: center; align-items: center; transition: all 0.2s ease-in-out; line-height: 24px; } .card-container .card:not(:last-child) { margin-right: 0; } .card.card-small { height: 16px; width: 168px; } .card-container .card:not(.highlight-card) { cursor: pointer; } .card-container .card:not(.highlight-card):hover { transform: translateY(-3px); box-shadow: 0 4px 17px rgba(0, 0, 0, 0.35); } .card-container .card:not(.highlight-card):hover .material-icons path { fill: rgb(105, 103, 103); } .card.highlight-card { background-color: #1976d2; color: white; font-weight: 600; border: none; width: auto; min-width: 30%; position: relative; } .card.card.highlight-card span { margin-left: 60px; } svg#rocket { width: 80px; position: absolute; left: -10px; top: -24px; } svg#rocket-smoke { height: calc(100vh - 95px); position: absolute; top: 10px; right: 180px; z-index: -10; } a, a:visited, a:hover { color: #1976d2; text-decoration: none; } a:hover { color: #125699; } .terminal { position: relative; width: 80%; max-width: 600px; border-radius: 6px; padding-top: 45px; margin-top: 8px; overflow: hidden; background-color: rgb(15, 15, 16); } .terminal::before { content: "\2022 \2022 \2022"; position: absolute; top: 0; left: 0; height: 4px; background: rgb(58, 58, 58); color: #c2c3c4; width: 100%; font-size: 2rem; line-height: 0; padding: 14px 0; text-indent: 4px; } .terminal pre { font-family: SFMono-Regular,Consolas,Liberation Mono,Menlo,monospace; color: white; padding: 0 1rem 1rem; margin: 0; } .circle-link { height: 40px; width: 40px; border-radius: 40px; margin: 8px; background-color: white; border: 1px solid #eeeeee; display: flex; justify-content: center; align-items: center; cursor: pointer; box-shadow: 0 1px 3px rgba(0, 0, 0, 0.12), 0 1px 2px rgba(0, 0, 0, 0.24); transition: 1s ease-out; } .circle-link:hover { transform: translateY(-0.25rem); box-shadow: 0px 3px 15px rgba(0, 0, 0, 0.2); } footer { margin-top: 8px; display: flex; align-items: center; line-height: 20px; } footer a { display: flex; align-items: center; } .github-star-badge { color: #24292e; display: flex; align-items: center; font-size: 12px; padding: 3px 10px; border: 1px solid rgba(27,31,35,.2); border-radius: 3px; background-image: linear-gradient(-180deg,#fafbfc,#eff3f6 90%); margin-left: 4px; font-weight: 600; font-family: -apple-system,BlinkMacSystemFont,Segoe UI,Helvetica,Arial,sans-serif,Apple Color Emoji,Segoe UI Emoji,Segoe UI Symbol; } .github-star-badge:hover { background-image: linear-gradient(-180deg,#f0f3f6,#e6ebf1 90%); border-color: rgba(27,31,35,.35); background-position: -.5em; } .github-star-badge .material-icons { height: 16px; width: 16px; margin-right: 4px; } svg#clouds { position: fixed; bottom: -160px; left: -230px; z-index: -10; width: 1920px; } /* Responsive Styles */ @media screen and (max-width: 767px) { .card-container > *:not(.circle-link) , .terminal { width: 100%; } .card:not(.highlight-card) { height: 16px; margin: 8px 0; } .card.highlight-card span { margin-left: 72px; } svg#rocket-smoke { right: 120px; transform: rotate(-5deg); } } @media screen and (max-width: 575px) { svg#rocket-smoke { display: none; visibility: hidden; } } </style>

<!-- Toolbar -->
<div class="toolbar" role="banner">
  <img width="40" alt="Angular Logo" src="data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHZpZXdCb3g9IjAgMCAyNTAgMjUwIj4KICAgIDxwYXRoIGZpbGw9IiNERDAwMzEiIGQ9Ik0xMjUgMzBMMzEuOSA2My4ybDE0LjIgMTIzLjFMMTI1IDIzMGw3OC45LTQzLjcgMTQuMi0xMjMuMXoiIC8+CiAgICA8cGF0aCBmaWxsPSIjQzMwMDJGIiBkPSJNMTI1IDMwdjIyLjItLjFWMjMwbDc4LjktNDMuNyAxNC4yLTEyMy4xTDEyNSAzMHoiIC8+CiAgICA8cGF0aCAgZmlsbD0iI0ZGRkZGRiIgZD0iTTEyNSA1Mi4xTDY2LjggMTgyLjZoMjEuN2wxMS43LTI5LjJoNDkuNGwxMS43IDI5LjJIMTgzTDEyNSA1Mi4xem0xNyA4My4zaC0zNGwxNy00MC45IDE3IDQwLjl6IiAvPgogIDwvc3ZnPg==" />
  <span>Welcome</span>
    <div class="spacer"></div>
    <a aria-label="Angular on twitter" target="_blank" rel="noopener" href="https://twitter.com/angular" title="Twitter">
      <svg id="twitter-logo" height="24" data-name="Logo" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 400 400">
        <rect width="400" height="400" fill="none"/>
        <path d="M153.62,301.59c94.34,0,145.94-78.16,145.94-145.94,0-2.22,0-4.43-.15-6.63A104.36,104.36,0,0,0,325,122.47a102.38,102.38,0,0,1-29.46,8.07,51.47,51.47,0,0,0,22.55-28.37,102.79,102.79,0,0,1-32.57,12.45,51.34,51.34,0,0,0-87.41,46.78A145.62,145.62,0,0,1,92.4,107.81a51.33,51.33,0,0,0,15.88,68.47A50.91,50.91,0,0,1,85,169.86c0,.21,0,.43,0,.65a51.31,51.31,0,0,0,41.15,50.28,51.21,51.21,0,0,1-23.16.88,51.35,51.35,0,0,0,47.92,35.62,102.92,102.92,0,0,1-63.7,22A104.41,104.41,0,0,1,75,278.55a145.21,145.21,0,0,0,78.62,23" fill="#fff"/>
      </svg>
    </a>
</div>

<div class="content" role="main">

  <!-- Highlight Card -->
  <div class="card highlight-card card-small">

    <svg id="rocket" alt="Rocket Ship" xmlns="http://www.w3.org/2000/svg" width="101.678" height="101.678" viewBox="0 0 101.678 101.678">
      <g id="Group_83" data-name="Group 83" transform="translate(-141 -696)">
        <circle id="Ellipse_8" data-name="Ellipse 8" cx="50.839" cy="50.839" r="50.839" transform="translate(141 696)" fill="#dd0031"/>
        <g id="Group_47" data-name="Group 47" transform="translate(165.185 720.185)">
          <path id="Path_33" data-name="Path 33" d="M3.4,42.615a3.084,3.084,0,0,0,3.553,3.553,21.419,21.419,0,0,0,12.215-6.107L9.511,30.4A21.419,21.419,0,0,0,3.4,42.615Z" transform="translate(0.371 3.363)" fill="#fff"/>
          <path id="Path_34" data-name="Path 34" d="M53.3,3.221A3.09,3.09,0,0,0,50.081,0,48.227,48.227,0,0,0,18.322,13.437c-6-1.666-14.991-1.221-18.322,7.218A33.892,33.892,0,0,1,9.439,25.1l-.333.666a3.013,3.013,0,0,0,.555,3.553L23.985,43.641a2.9,2.9,0,0,0,3.553.555l.666-.333A33.892,33.892,0,0,1,32.647,53.3c8.55-3.664,8.884-12.326,7.218-18.322A48.227,48.227,0,0,0,53.3,3.221ZM34.424,9.772a6.439,6.439,0,1,1,9.106,9.106,6.368,6.368,0,0,1-9.106,0A6.467,6.467,0,0,1,34.424,9.772Z" transform="translate(0 0.005)" fill="#fff"/>
        </g>
      </g>
    </svg>

    <span>{{ title }} app is running!</span>

    <svg id="rocket-smoke" alt="Rocket Ship Smoke" xmlns="http://www.w3.org/2000/svg" width="516.119" height="1083.632" viewBox="0 0 516.119 1083.632">
      <path id="Path_40" data-name="Path 40" d="M644.6,141S143.02,215.537,147.049,870.207s342.774,201.755,342.774,201.755S404.659,847.213,388.815,762.2c-27.116-145.51-11.551-384.124,271.9-609.1C671.15,139.365,644.6,141,644.6,141Z" transform="translate(-147.025 -140.939)" fill="#f5f5f5"/>
    </svg>

  </div>

  <!-- Resources -->
  <h2>Resources</h2>
  <p>Here are some links to help you get started:</p>

  <div class="card-container">
    <a class="card" target="_blank" rel="noopener" href="https://angular.io/tutorial">
      <svg class="material-icons" xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24"><path d="M5 13.18v4L12 21l7-3.82v-4L12 17l-7-3.82zM12 3L1 9l11 6 9-4.91V17h2V9L12 3z"/></svg>

      <span>Learn Angular</span>

      <svg class="material-icons" xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24"><path d="M10 6L8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg>    </a>

    <a class="card" target="_blank" rel="noopener" href="https://angular.io/cli">
      <svg class="material-icons" xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24"><path d="M9.4 16.6L4.8 12l4.6-4.6L8 6l-6 6 6 6 1.4-1.4zm5.2 0l4.6-4.6-4.6-4.6L16 6l6 6-6 6-1.4-1.4z"/></svg>

      <span>CLI Documentation</span>

      <svg class="material-icons" xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24"><path d="M10 6L8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg>
    </a>

    <a class="card" target="_blank" rel="noopener" href="https://blog.angular.io/">
      <svg class="material-icons" xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24"><path d="M13.5.67s.74 2.65.74 4.8c0 2.06-1.35 3.73-3.41 3.73-2.07 0-3.63-1.67-3.63-3.73l.03-.36C5.21 7.51 4 10.62 4 14c0 4.42 3.58 8 8 8s8-3.58 8-8C20 8.61 17.41 3.8 13.5.67zM11.71 19c-1.78 0-3.22-1.4-3.22-3.14 0-1.62 1.05-2.76 2.81-3.12 1.77-.36 3.6-1.21 4.62-2.58.39 1.29.59 2.65.59 4.04 0 2.65-2.15 4.8-4.8 4.8z"/></svg>

      <span>Angular Blog</span>

      <svg class="material-icons" xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24"><path d="M10 6L8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg>
    </a>

  </div>

  <!-- Next Steps -->
  <h2>Next Steps</h2>
  <p>What do you want to do next with your app?</p>

  <input type="hidden" #selection>

  <div class="card-container">
    <div class="card card-small" (click)="selection.value = 'component'" tabindex="0">
        <svg class="material-icons" xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24"><path d="M19 13h-6v6h-2v-6H5v-2h6V5h2v6h6v2z"/></svg>

      <span>New Component</span>
    </div>

    <div class="card card-small" (click)="selection.value = 'material'" tabindex="0">
        <svg class="material-icons" xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24"><path d="M19 13h-6v6h-2v-6H5v-2h6V5h2v6h6v2z"/></svg>

      <span>Angular Material</span>
    </div>

    <div class="card card-small" (click)="selection.value = 'pwa'" tabindex="0">
        <svg class="material-icons" xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24"><path d="M19 13h-6v6h-2v-6H5v-2h6V5h2v6h6v2z"/></svg>

      <span>Add PWA Support</span>
    </div>

    <div class="card card-small" (click)="selection.value = 'dependency'" tabindex="0">
      <svg class="material-icons" xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24"><path d="M19 13h-6v6h-2v-6H5v-2h6V5h2v6h6v2z"/></svg>

      <span>Add Dependency</span>
    </div>

    <div class="card card-small" (click)="selection.value = 'test'" tabindex="0">
      <svg class="material-icons" xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24"><path d="M19 13h-6v6h-2v-6H5v-2h6V5h2v6h6v2z"/></svg>

      <span>Run and Watch Tests</span>
    </div>

    <div class="card card-small" (click)="selection.value = 'build'" tabindex="0">
      <svg class="material-icons" xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24"><path d="M19 13h-6v6h-2v-6H5v-2h6V5h2v6h6v2z"/></svg>

      <span>Build for Production</span>
    </div>
  </div>

  <!-- Terminal -->
  <div class="terminal" [ngSwitch]="selection.value">
      <pre *ngSwitchDefault>ng generate component xyz</pre>
      <pre *ngSwitchCase="'material'">ng add @angular/material</pre>
      <pre *ngSwitchCase="'pwa'">ng add @angular/pwa</pre>
      <pre *ngSwitchCase="'dependency'">ng add _____</pre>
      <pre *ngSwitchCase="'test'">ng test</pre>
      <pre *ngSwitchCase="'build'">ng build --prod</pre>
  </div>

  <!-- Links -->
  <div class="card-container">
    <a class="circle-link" title="Animations" href="https://angular.io/guide/animations" target="_blank" rel="noopener">
      <svg id="Group_20" data-name="Group 20" xmlns="http://www.w3.org/2000/svg" width="21.813" height="23.453" viewBox="0 0 21.813 23.453">
        <path id="Path_15" data-name="Path 15" d="M4099.584,972.736h0l-10.882,3.9,1.637,14.4,9.245,5.153,9.245-5.153,1.686-14.4Z" transform="translate(-4088.702 -972.736)" fill="#ffa726"/>
        <path id="Path_16" data-name="Path 16" d="M4181.516,972.736v23.453l9.245-5.153,1.686-14.4Z" transform="translate(-4170.633 -972.736)" fill="#fb8c00"/>
        <path id="Path_17" data-name="Path 17" d="M4137.529,1076.127l-7.7-3.723,4.417-2.721,7.753,3.723Z" transform="translate(-4125.003 -1058.315)" fill="#ffe0b2"/>
        <path id="Path_18" data-name="Path 18" d="M4137.529,1051.705l-7.7-3.723,4.417-2.721,7.753,3.723Z" transform="translate(-4125.003 -1036.757)" fill="#fff3e0"/>
        <path id="Path_19" data-name="Path 19" d="M4137.529,1027.283l-7.7-3.723,4.417-2.721,7.753,3.723Z" transform="translate(-4125.003 -1015.199)" fill="#fff"/>
      </svg>
    </a>

    <a class="circle-link" title="CLI" href="https://cli.angular.io/" target="_blank" rel="noopener">
      <svg alt="Angular CLI Logo" xmlns="http://www.w3.org/2000/svg" width="21.762" height="23.447" viewBox="0 0 21.762 23.447">
        <g id="Group_21" data-name="Group 21" transform="translate(0)">
          <path id="Path_20" data-name="Path 20" d="M2660.313,313.618h0l-10.833,3.9,1.637,14.4,9.2,5.152,9.244-5.152,1.685-14.4Z" transform="translate(-2649.48 -313.618)" fill="#37474f"/>
          <path id="Path_21" data-name="Path 21" d="M2741.883,313.618v23.447l9.244-5.152,1.685-14.4Z" transform="translate(-2731.05 -313.618)" fill="#263238"/>
          <path id="Path_22" data-name="Path 22" d="M2692.293,379.169h11.724V368.618h-11.724Zm11.159-.6h-10.608v-9.345h10.621v9.345Z" transform="translate(-2687.274 -362.17)" fill="#fff"/>
          <path id="Path_23" data-name="Path 23" d="M2709.331,393.688l.4.416,2.265-2.28-2.294-2.294-.4.4,1.893,1.893Z" transform="translate(-2702.289 -380.631)" fill="#fff"/>
          <rect id="Rectangle_12" data-name="Rectangle 12" width="3.517" height="0.469" transform="translate(9.709 13.744)" fill="#fff"/>
        </g>
      </svg>
    </a>

    <a class="circle-link" title="Augury" href="https://augury.rangle.io/" target="_blank" rel="noopener">
      <svg alt="Angular Augury Logo" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="21.81" height="23.447" viewBox="0 0 21.81 23.447">
        <defs>
          <clipPath id="clip-path">
            <rect id="Rectangle_13" data-name="Rectangle 13" width="10.338" height="10.27" fill="none"/>
          </clipPath>
        </defs>
        <g id="Group_25" data-name="Group 25" transform="translate(0)">
          <path id="Path_24" data-name="Path 24" d="M3780.155,311.417h0l-10.881,3.9,1.637,14.4,9.244,5.152,9.244-5.152,1.685-14.4Z" transform="translate(-3769.274 -311.417)" fill="#4a3493"/>
          <path id="Path_25" data-name="Path 25" d="M3862.088,311.417v23.447l9.244-5.152,1.685-14.4Z" transform="translate(-3851.207 -311.417)" fill="#311b92"/>
          <g id="Group_24" data-name="Group 24" transform="translate(6.194 6.73)" opacity="0.5">
            <g id="Group_23" data-name="Group 23" transform="translate(0 0)">
              <g id="Group_22" data-name="Group 22" clip-path="url(#clip-path)">
                <path id="Path_26" data-name="Path 26" d="M3832.4,373.252a5.168,5.168,0,1,1-5.828-4.383,5.216,5.216,0,0,1,2.574.3,3.017,3.017,0,1,0,3.252,4.086Z" transform="translate(-3822.107 -368.821)" fill="#fff"/>
              </g>
            </g>
          </g>
          <path id="Path_27" data-name="Path 27" d="M3830.582,370.848a5.162,5.162,0,1,1-3.254-4.086,3.017,3.017,0,1,0,3.252,4.086Z" transform="translate(-3814.311 -359.969)" fill="#fff"/>
        </g>
      </svg>
    </a>

    <a class="circle-link" title="Protractor" href="https://www.protractortest.org/" target="_blank" rel="noopener">
      <svg alt="Angular Protractor Logo" xmlns="http://www.w3.org/2000/svg" width="21.81" height="23.447" viewBox="0 0 21.81 23.447">
        <g id="Group_26" data-name="Group 26" transform="translate(0)">
          <path id="Path_28" data-name="Path 28" d="M4620.155,311.417h0l-10.881,3.9,1.637,14.4,9.244,5.152,9.244-5.152,1.685-14.4Z" transform="translate(-4609.274 -311.417)" fill="#e13439"/>
          <path id="Path_29" data-name="Path 29" d="M4702.088,311.417v23.447l9.244-5.152,1.685-14.4Z" transform="translate(-4691.207 -311.417)" fill="#b52f32"/>
          <path id="Path_30" data-name="Path 30" d="M4651.044,369.58v-.421h1.483a7.6,7.6,0,0,0-2.106-5.052l-1.123,1.123-.3-.3,1.122-1.121a7.588,7.588,0,0,0-4.946-2.055v1.482h-.421v-1.485a7.589,7.589,0,0,0-5.051,2.058l1.122,1.121-.3.3-1.123-1.123a7.591,7.591,0,0,0-2.106,5.052h1.482v.421h-1.489v1.734h15.241V369.58Zm-10.966-.263a4.835,4.835,0,0,1,9.67,0Z" transform="translate(-4634.008 -355.852)" fill="#fff"/>
        </g>
      </svg>
    </a>

    <a class="circle-link" title="Find a Local Meetup" href="https://www.meetup.com/find/?keywords=angular" target="_blank" rel="noopener">
      <svg alt="Meetup Logo" xmlns="http://www.w3.org/2000/svg" width="24.607" height="23.447" viewBox="0 0 24.607 23.447">
        <path id="logo--mSwarm" d="M21.221,14.95A4.393,4.393,0,0,1,17.6,19.281a4.452,4.452,0,0,1-.8.069c-.09,0-.125.035-.154.117a2.939,2.939,0,0,1-2.506,2.091,2.868,2.868,0,0,1-2.248-.624.168.168,0,0,0-.245-.005,3.926,3.926,0,0,1-2.589.741,4.015,4.015,0,0,1-3.7-3.347,2.7,2.7,0,0,1-.043-.38c0-.106-.042-.146-.143-.166a3.524,3.524,0,0,1-1.516-.69A3.623,3.623,0,0,1,2.23,14.557a3.66,3.66,0,0,1,1.077-3.085.138.138,0,0,0,.026-.2,3.348,3.348,0,0,1-.451-1.821,3.46,3.46,0,0,1,2.749-3.28.44.44,0,0,0,.355-.281,5.072,5.072,0,0,1,3.863-3,5.028,5.028,0,0,1,3.555.666.31.31,0,0,0,.271.03A4.5,4.5,0,0,1,18.3,4.7a4.4,4.4,0,0,1,1.334,2.751,3.658,3.658,0,0,1,.022.706.131.131,0,0,0,.1.157,2.432,2.432,0,0,1,1.574,1.645,2.464,2.464,0,0,1-.7,2.616c-.065.064-.051.1-.014.166A4.321,4.321,0,0,1,21.221,14.95ZM13.4,14.607a2.09,2.09,0,0,0,1.409,1.982,4.7,4.7,0,0,0,1.275.221,1.807,1.807,0,0,0,.9-.151.542.542,0,0,0,.321-.545.558.558,0,0,0-.359-.534,1.2,1.2,0,0,0-.254-.078c-.262-.047-.526-.086-.787-.138a.674.674,0,0,1-.617-.75,3.394,3.394,0,0,1,.218-1.109c.217-.658.509-1.286.79-1.918a15.609,15.609,0,0,0,.745-1.86,1.95,1.95,0,0,0,.06-1.073,1.286,1.286,0,0,0-1.051-1.033,1.977,1.977,0,0,0-1.521.2.339.339,0,0,1-.446-.042c-.1-.092-.2-.189-.307-.284a1.214,1.214,0,0,0-1.643-.061,7.563,7.563,0,0,1-.614.512A.588.588,0,0,1,10.883,8c-.215-.115-.437-.215-.659-.316a2.153,2.153,0,0,0-.695-.248A2.091,2.091,0,0,0,7.541,8.562a9.915,9.915,0,0,0-.405.986c-.559,1.545-1.015,3.123-1.487,4.7a1.528,1.528,0,0,0,.634,1.777,1.755,1.755,0,0,0,1.5.211,1.35,1.35,0,0,0,.824-.858c.543-1.281,1.032-2.584,1.55-3.875.142-.355.28-.712.432-1.064a.548.548,0,0,1,.851-.24.622.622,0,0,1,.185.539,2.161,2.161,0,0,1-.181.621c-.337.852-.68,1.7-1.018,2.552a2.564,2.564,0,0,0-.173.528.624.624,0,0,0,.333.71,1.073,1.073,0,0,0,.814.034,1.22,1.22,0,0,0,.657-.655q.758-1.488,1.511-2.978.35-.687.709-1.37a1.073,1.073,0,0,1,.357-.434.43.43,0,0,1,.463-.016.373.373,0,0,1,.153.387.7.7,0,0,1-.057.236c-.065.157-.127.316-.2.469-.42.883-.846,1.763-1.262,2.648A2.463,2.463,0,0,0,13.4,14.607Zm5.888,6.508a1.09,1.09,0,0,0-2.179.006,1.09,1.09,0,0,0,2.179-.006ZM1.028,12.139a1.038,1.038,0,1,0,.01-2.075,1.038,1.038,0,0,0-.01,2.075ZM13.782.528a1.027,1.027,0,1,0-.011,2.055A1.027,1.027,0,0,0,13.782.528ZM22.21,6.95a.882.882,0,0,0-1.763.011A.882.882,0,0,0,22.21,6.95ZM4.153,4.439a.785.785,0,1,0,.787-.78A.766.766,0,0,0,4.153,4.439Zm8.221,18.22a.676.676,0,1,0-.677.666A.671.671,0,0,0,12.374,22.658ZM22.872,12.2a.674.674,0,0,0-.665.665.656.656,0,0,0,.655.643.634.634,0,0,0,.655-.644A.654.654,0,0,0,22.872,12.2ZM7.171-.123A.546.546,0,0,0,6.613.43a.553.553,0,1,0,1.106,0A.539.539,0,0,0,7.171-.123ZM24.119,9.234a.507.507,0,0,0-.493.488.494.494,0,0,0,.494.494.48.48,0,0,0,.487-.483A.491.491,0,0,0,24.119,9.234Zm-19.454,9.7a.5.5,0,0,0-.488-.488.491.491,0,0,0-.487.5.483.483,0,0,0,.491.479A.49.49,0,0,0,4.665,18.936Z" transform="translate(0 0.123)" fill="#f64060"/>
      </svg>
    </a>

    <a class="circle-link" title="Join the Conversation on Gitter" href="https://gitter.im/angular/angular" target="_blank" rel="noopener">
      <svg alt="Gitter Logo" xmlns="http://www.w3.org/2000/svg" width="19.447" height="19.447" viewBox="0 0 19.447 19.447">
        <g id="Group_40" data-name="Group 40" transform="translate(-1612 -405)">
          <rect id="Rectangle_19" data-name="Rectangle 19" width="19.447" height="19.447" transform="translate(1612 405)" fill="#e60257"/>
          <g id="gitter" transform="translate(1617.795 408.636)">
            <g id="Group_33" data-name="Group 33" transform="translate(0 0)">
              <rect id="Rectangle_15" data-name="Rectangle 15" width="1.04" height="9.601" transform="translate(2.304 2.324)" fill="#fff"/>
              <rect id="Rectangle_16" data-name="Rectangle 16" width="1.04" height="9.601" transform="translate(4.607 2.324)" fill="#fff"/>
              <rect id="Rectangle_17" data-name="Rectangle 17" width="1.04" height="4.648" transform="translate(6.91 2.324)" fill="#fff"/>
              <rect id="Rectangle_18" data-name="Rectangle 18" width="1.04" height="6.971" transform="translate(0 0)" fill="#fff"/>
            </g>
          </g>
        </g>
      </svg>
    </a>
  </div>

  <!-- Footer -->
  <footer>
      Love Angular?&nbsp;
      <a href="https://github.com/angular/angular" target="_blank" rel="noopener"> Give our repo a star.
        <div class="github-star-badge">
            <svg class="material-icons" xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24"><path d="M0 0h24v24H0z" fill="none"/><path d="M12 17.27L18.18 21l-1.64-7.03L22 9.24l-7.19-.61L12 2 9.19 8.63 2 9.24l5.46 4.73L5.82 21z"/></svg>
          Star
        </div>
      </a>
      <a href="https://github.com/angular/angular" target="_blank" rel="noopener">
        <svg class="material-icons" xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24"><path d="M10 6L8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z" fill="#1976d2"/><path d="M0 0h24v24H0z" fill="none"/></svg>
      </a>
  </footer>

  <svg id="clouds" alt="Gray Clouds Background" xmlns="http://www.w3.org/2000/svg" width="2611.084" height="485.677" viewBox="0 0 2611.084 485.677">
    <path id="Path_39" data-name="Path 39" d="M2379.709,863.793c10-93-77-171-168-149-52-114-225-105-264,15-75,3-140,59-152,133-30,2.83-66.725,9.829-93.5,26.25-26.771-16.421-63.5-23.42-93.5-26.25-12-74-77-130-152-133-39-120-212-129-264-15-54.084-13.075-106.753,9.173-138.488,48.9-31.734-39.726-84.4-61.974-138.487-48.9-52-114-225-105-264,15a162.027,162.027,0,0,0-103.147,43.044c-30.633-45.365-87.1-72.091-145.206-58.044-52-114-225-105-264,15-75,3-140,59-152,133-53,5-127,23-130,83-2,42,35,72,70,86,49,20,106,18,157,5a165.625,165.625,0,0,0,120,0c47,94,178,113,251,33,61.112,8.015,113.854-5.72,150.492-29.764a165.62,165.62,0,0,0,110.861-3.236c47,94,178,113,251,33,31.385,4.116,60.563,2.495,86.487-3.311,25.924,5.806,55.1,7.427,86.488,3.311,73,80,204,61,251-33a165.625,165.625,0,0,0,120,0c51,13,108,15,157-5a147.188,147.188,0,0,0,33.5-18.694,147.217,147.217,0,0,0,33.5,18.694c49,20,106,18,157,5a165.625,165.625,0,0,0,120,0c47,94,178,113,251,33C2446.709,1093.793,2554.709,922.793,2379.709,863.793Z" transform="translate(142.69 -634.312)" fill="#eee"/>
  </svg>

</div>

<!-- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * -->
<!-- * * * * * * * * * * * The content above * * * * * * * * * * * -->
<!-- * * * * * * * * * * is only a placeholder * * * * * * * * * * -->
<!-- * * * * * * * * * * and can be replaced. * * * * * * * * * * * -->
<!-- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * -->
<!-- * * * * * * * * * * End of Placeholder * * * * * * * * * * * -->
<!-- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * -->



<router-outlet></router-outlet>

元数据

使用 @Component 修饰器附加元数据，接受一个必需的配置对象，该对象包含 Angular 创建和呈现该组件和它的视图所需的信息。

片段2中的代码使用 @Component 配置了 3 个选项：

selector：一个 CSS 选择器，告诉 Angular 在父 HTML 文件中找到 selector 标记的地方创建和插入此组件的一个实例
templateUrl：组件的 HTML 文件
styleUrls：组件的样式表，比如 .scss 文件

组件模板位置

模板是一个 HTML 文件，用于告诉 Angular 如何呈现组件。在 片段2 的templateUrl属性，指向一个名为 app.component.html 的视图。

组件内的数据绑定

数据绑定用于告诉 Angular 如何呈现组件。在 app.component.ts 文件中，title 的值在类内设置，在 app.component.html 文件中使用。数据绑定可以是单向或双向的。在本例中，如果在双花括号 {{ }} 内提及该变量，则该映射是单向的。值从类传递到 HTML 文件。

自定义组件和路由

基础应用程序有一个模块、一个组件、一个类、一个模板、元数据和数据绑定 — 但它仍缺少 4 个其他的重要部分：

多个组件
路由
服务
微服务的使用

接下来，将创建这些自定义组件。运行以下命令：

ng generate component Menu：在 AppModule 根模块（同一个文件夹中）内创建 Menu 组件。
ng generate component Weather：在 AppModule 根模块内名为 weather 的子文件夹中创建 Weather 组件。

执行完后将在app.module.ts中添加4个组件的内容：

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';

//新添加的4个组件
import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';
import { MenuComponent } from './menu.component';
import { WeatherComponent } from './weather/weather.component';

@NgModule({
  declarations: [
    AppComponent,
    MenuComponent,
    WeatherComponent
  ],
  imports: [
    BrowserModule,
    AppRoutingModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

创建路由

要让 Angular 能在组件之间导航，需要创建路由。使用片段3的内容覆盖 menu.component.html 文件，以便 HTML 包含所有组件的正确菜单。

片段3：src/app/menu.component.html

<div class="row">
    <div class="col-xs-12">
        <ul class="nav nav-pills">
            <li routerLinkActive="active"> <a [routerLink]="['/weather']">天气预报</a></li>
        </ul>
    </div>
</div>

接下来，将 URL 路径映射到组件。在根模块的文件夹中，创建 src/app/app-routing.module.ts 的配置文件，配置如下。

import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';
import { WeatherComponent } from "./weather/weather.component";

const routes: Routes = [
  { path: "", redirectTo: "/weather", pathMatch: "full" },
  { path: "weather", component: WeatherComponent }
];

@NgModule({ imports: [RouterModule.forRoot(routes)], exports: [RouterModule] })
export class AppRoutingModule { }

修改 app.component.html内容，代码如下：

<div class="container">
  <app-menu></app-menu>
  <hr>
  <router-outlet></router-outlet>
</div>

在 app.module.ts 文件中添加路由信息，如下：

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';

import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';
import { MenuComponent } from './menu.component';
import { WeatherComponent } from './weather/weather.component';

@NgModule({ declarations: [ AppComponent, MenuComponent, WeatherComponent ], imports: [ BrowserModule, AppRoutingModule ], providers: [], bootstrap: [AppComponent] })
export class AppModule { }

再次运行应用程序：ng serve，运行结果如下：

创建服务

运行以下命令创建服务

ng generate service Shared

添加接口查询服务，需要申请appid的话，可以去天气API网站申请。代码如下：

import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { throwError as observableThrowError } from 'rxjs';
import { catchError, tap } from 'rxjs/operators';

@Injectable({
  providedIn: 'root'
})
export class SharedService {

  weatherURL1 = "https://www.tianqiapi.com/api/?version=v61&appid=45999158&appsecret=WL6GeLkx&cityid=";
  weatherURL2 = "&city=";
  totReqsMade: number = 0;
  constructor(private _http: HttpClient) {

  }
  findWeather(cityid, city) {
    this.totReqsMade = this.totReqsMade + 1;
    return this._http
      .get(this.weatherURL1 + cityid + this.weatherURL2 + city)
      .pipe(
        tap((response:any) => response),
        catchError(this.handleError)
      )
  }
  private handleError(error: any) {
    return observableThrowError(error.error || 'Server error');
  }
}

@Injectable() ：表明此 service 可注入到其他组件中
totReqsMade ：变量在这里声明，用于在 3 个组件之间传递它的值。将跟踪为获得微服务结果而发出的服务请求总数。
定义了方法：findWeather()

将 weather.component.ts 替换如下代码：

import { Component, OnInit } from '@angular/core';
import { SharedService } from "./../shared.service";

@Component({
  selector: 'app-weather',
  templateUrl: './weather.component.html',
  styleUrls: ['./weather.component.scss']
})
export class WeatherComponent implements OnInit {
  cityid: string = "101280601";
  city: string = "深圳";
  op_city: string = "";
  op_region: string = "";
  op_country: string = "";
  op_data: string = "";
  op_today: string = "";
  constructor(public _sharedService: SharedService) {}

  ngOnInit() {}

  callWeatherService() {
    this._sharedService.findWeather(this.cityid, this.city).subscribe(
      lstresult => {
        this.op_city = lstresult["city"];
        this.op_country = lstresult["country"];
        this.op_data = lstresult;
        this.op_today = [lstresult["wea"],[lstresult["tem2"],"-",lstresult["tem1"],"℃"].join("")].join(" ");
      },
      error => {
        console.log("Error. The findWeather result JSON value is as follows:");
        console.log(error);
      }
    );
  }
}

更新 app.module.ts 文件，加入这些服务：

import { BrowserModule } from "@angular/platform-browser";
import { NgModule } from "@angular/core";
import { FormsModule } from "@angular/forms";
import { HttpModule } from "@angular/http";

import { AppComponent } from "./app.component";
import { MenuComponent } from "./menu.component";
import { WeatherComponent } from "./weather/weather.component";
import { CONST_ROUTING } from "./app.routing";
import { SharedService } from "./shared.service";

@NgModule({ declarations: [AppComponent, MenuComponent, WeatherComponent, CurrencyComponent, MovieComponent], imports: [BrowserModule, FormsModule, HttpModule, CONST_ROUTING], providers: [SharedService], bootstrap: [AppComponent] })
export class AppModule {}

组件视图

现在外面需要修改 HTML 文件，加入这些服务的调用。

weather.component.html

<h2>天气预报</h2>
<div class="col-md-8 col-md-offset-2">
    <div class="form-group">
        <input type="text" value="{{this.cityid}}" class="form-control" placeholder="请输入城市ID..."><br>
        <input type="text" value="{{this.city}}" class="form-control" placeholder="请输入城市..."><br>
        <button type="button" class="btn btn-primary" (click)="callWeatherService()">立即查询</button>
        <br><br><br>
        <br>
        <p class="well lead">
            <i>城市：</i> {{ this.op_city }} {{ this.op_country }} <br>
            <i>天气：</i> {{ this.op_today }} <br>
        </p>
        <p class="text-info">天气服务请求次数：
            <span class="badge">{{this._sharedService.totReqsMade}}</span>
        </p>
    </div>
</div>

运行应用程序

运行应用程序，按照默认值执行查询深圳天气

功能实现了，接下来就优化ui，这里我们引入bootstrap，在根目录的index.html文件添加样式文件：

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">

瞬间就变得美观了！

完

今天的文章TypeScript 创建单页天气查询应用程序分享到此就结束了，感谢您的阅读。

版权声明：本文内容由互联网用户自发贡献，该文观点仅代表作者本人。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容，请发送邮件至举报，一经查实，本站将立刻删除。
如需转载请保留出处：https://bianchenghao.cn/22878.html