如何使用angular 2中的typescript从文本框中获取值

Question

我是angular2/typescript的初学者我正在尝试从两个文本框中获取数字并添加两个数字并使用插值显示结果

@Component({
selector: 'my-app',
template: 
`<h1>Hello {{name}}</h1>
<h1>{{D}}</h1>
 <form>
  <p>first number:<input type="text" id="num1"></p>
  <p>second number:<input type ="text1" id="num2"></p>
  <h1> {{result}}</h1>
  </form>
   <test-app></test-app>`
  })

  export class AppComponent 
  { 
 name = 'Angular'; 
 value : number;value1 : number;result:number;
  constructor(value : number,value1 : number,result:number)
  {

  this.value = parseFloat
  ((document.getElementById("text") as HTMLInputElement).value);
  this.value1 = parseFloat((document.getElementById("text1") 
  as HTMLInputElement).value);
  this.result=this.value+this.value1;
  }}

Answer 1

最简单的方法是使用模板引用变量：

@Component({
  selector: 'app-little-tour',
  template: `
    <input #newHero > 
    <button (click)="addHero(newHero.value)">Add</button>
})

export class LittleTourComponent {
  addHero(newHero: string) {
    console.log(newHero)
  }
}

可以在这里找到有关Angular用户输入的完整指南：https : //angular.io/guide/user-input

Answer 2

如果你没有使用ngModel:

var   num1= ((document.getElementById("num1") as HTMLInputElement).value);
var   num2= ((document.getElementById("num2") as HTMLInputElement).value);
var result=parseInt(num1)+parseInt(num2);
console.log(result);

Answer 3

HTML

<p>first number:<input type="text" id="num1" [(ngModel)] = "value" ></p>
<p>second number:<input type ="text1" id="num2" [(ngModel)] = "value1"></p>
<h1> {{value + value1}}</h1>

组件类

 export class AppComponent {}

Answer 4

的HTML

<p>first number:<input type="number" [(ngModel)]='a'></p>
<p>second number:<input type ="number" [(ngModel)]='b'></p>
<h1>{{a + b}}</h1>

零件

export class AppComponent 
  { 
 a: number = 0; //set default value as 0
 b: number = 0;

}