typescript 如何生成随机数以在角度 2 上输入表单组索引
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How to generate random number to input form group index on angular 2
提问by John Lesner
I have a Dynamic form input where the user can press a button to add more input fields that will be bound to the template with ngFor like this:
我有一个动态表单输入，用户可以在其中按下按钮添加更多输入字段，这些字段将使用 ngFor 绑定到模板，如下所示：
*ngFor="let data of getTasks(myFormdata); let i=index"
and the ts file
和 ts 文件
getTasks(myFormdata) {
return myFormdata.get('inputs').controls
}
All this works great. The user can add new input fields, but I have a button that will generate a random number and set the random number to the input value. Since I am new to Angular 2, I can't seem to make it happen when there is more than one input field. The method to generate the random number into the field is the following:
所有这些都很好用。用户可以添加新的输入字段，但我有一个按钮可以生成一个随机数并将随机数设置为输入值。由于我是 Angular 2 的新手，当有多个输入字段时，我似乎无法实现它。生成随机数进入字段的方法如下：
getRandomNumber() {
const random = Math.floor(Math.random() * (999999 - 100000)) + 100000;
const control = <FormArray>this.myFormdata.controls['inputs'];
control.setValue([{numbers: random, pari: 25}])
}
What is missing from my getRandomNumber()method to make it generate a random number for each added field?
我的getRandomNumber()方法缺少什么来为每个添加的字段生成一个随机数？
回答by John Lesner
I got the solution... the following is my solution
我得到了解决方案……以下是我的解决方案
getRandomNumber(i: number) {
let random = Math.floor(Math.random() * (999999 - 100000)) + 100000;
const control = <FormArray>this.myFormdata.controls['inputs'];
const random = this._fb.group({numbers: +quickpicked, pari: 25});
control.setControl(i, random)
}
回答by Rupak Thapa Magar
export class AppComponent {
title = 'codegenerator';
date = new Date();
codeGenerated = '';
evtMsg: any;
randomString() {
const chars = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXTZabcdefghiklmnopqrstuvwxyz';
const stringLength = 10;
let randomstring = '';
for (let i = 0; i < stringLength; i++) {
const rnum = Math.floor(Math.random() * chars.length);
randomstring += chars.substring(rnum, rnum + 1);
}
this.codeGenerated = randomstring;
return 0;
}
} <div class="card text-center" style="width: 40rem;">
<div class="card-head">
<button (click)="randomString()" class="d-inline bg-primary btn-lg text-white">Generate code</button>
</div>
<div class="card-body">
<h1 class="display-2 text-dark">{{codeGenerated}}</h1>
</div>
</div>