ngFor和ngModel推入数组时重置输入

问题描述

我正在尝试创建一个表单，您可以在发送前添加多行.为此，我将数据存储在Lines数组中，并使用ngFor和ngModel将数据绑定/检索到表单中.

I'm trying to create a form where you can add multiple lines before sending it. For that I'm using storing data in an array of Lines and use ngFor and ngModel to bind / retrieve data into my form.

这是我的代码的样子

export class MyComponent implements OnInit {
  lines : Line[] = [];

  constructor() { }

  ngOnInit() {
    this.lines.push(new Line("XXXXXX1",0,0));
  }

  addLine(){
    let line = (new Line("XXXXXX1",0,0));
    this.lines.push(line);
  }

  save(){
    console.log(this.lines);
  }
}

class Line {
  type: string;
  qteRejet : number;
  qteComm : number;

  constructor(type: string = "XXXX1", qteRej: number = 0, qteComm : number = 0){
    this.type = type;
    this.qteRejet = qteRej;
    this.qteComm = qteComm;
  }
}

和表格:

      <div class="form-group">
          <div class="row" *ngFor="let line of lines; let ind=index;">
            <div class="col-lg-1">
              <i class="fa fa-2x fa-plus-square add-btn" (click)="addLine()" *ngIf="lines[lines.length-1] === line"></i>
            </div>
            <div class="col-lg-3">
              <select class="form-control" name="type" [(ngModel)]="lines[ind].type">
                <option>XXXXXX1</option>
                <option>XXXXXX2</option>
                <option>XXXXXX3</option>
              </select>
            </div>
            <div class="col-lg-4">
              <input class="form-control" type="number" min="0" name="qteCommande" [(ngModel)]="lines[ind].qteComm">
            </div>
            <div class="col-lg-4">
              <input class="form-control" type="number" min="0" name="qteRejet" [(ngModel)]="lines[ind].qteRejet">
            </div>
          </div>
        </div>

当我一次添加所有行时，该表单运行完美.现在，由于某种原因，当我尝试填充一行然后添加另一行时，表单将重置先前输入的行.

When I add all the lines at once, the form works perfectly. Now when I try to fill a line then add another line, for some reason, the form resets the lines previously entered.

但是当我检查数组时，它仍然具有输入的值

But when I check my array, it still has the entered values

有人可以解释这里发生的事情/我在做什么错吗?任何帮助将不胜感激.

Can someone explain what is going on here / what I am doing wrong ? Any help would be greatly appreciated.

如 @Ploppy 所建议，我尝试使用trackBy并将ID添加到我的行中.我还将这一行添加到表单中:

EDIT : I tried, as suggested by @Ploppy to use trackBy and added an id to my lines. I also added this line to the form :

<p>{{line.id}} | {{line.type}} | {{line.qteComm}} | {{line.qteRejet}}</p>

这就是正在发生的事情:

And this is what's happening :

窗体将重置，但值已正确绑定.

The form resets but the values are correctly binded.

推荐答案

所以我终于在代码中找出了问题所在.我的输入位于form内，并添加新行以添加具有相同name的输入(在Agular 2中不允许这样做).用name=attribute-{{id}}替换我的name属性解决了该问题.

So I finally figured out the problem in my code. My inputs were inside a form, and adding a new line added an input with the same name(Which is not allowed in Agular 2). Replacing my name attributes by name=attribute-{{id}}solved the problem.

<div class="form-group">
      <div class="row" *ngFor="let line of lines; let ind=index;">
        <div class="col-lg-1">
          <i class="fa fa-2x fa-plus-square add-btn" (click)="addLine()" *ngIf="lines[lines.length-1] === line"></i>
        </div>
        <div class="col-lg-3">
          <select class="form-control" name="type-{{ind}}" [(ngModel)]="lines[ind].type">
            <option>XXXXXX1</option>
            <option>XXXXXX2</option>
            <option>XXXXXX3</option>
          </select>
        </div>
        <div class="col-lg-4">
          <input class="form-control" type="number" min="0" name="qteCommande-{{ind}}" [(ngModel)]="lines[ind].qteComm">
        </div>
        <div class="col-lg-4">
          <input class="form-control" type="number" min="0" name="qteRejet-{{ind}}" [(ngModel)]="lines[ind].qteRejet">
        </div>
      </div>
    </div>

这是一个汇总所有内容的柱塞: 柱塞

Here is a Plunker that summaries everything : Plunker

这篇关于ngFor和ngModel推入数组时重置输入的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！