Angular 8 ngFor - 如何获取行 ID

Question

My code:

    <div class="row" *ngFor="let evidence of evidences, index as i">
            <div class="col">
              {{i}}
              <input type='file' id="file" style="display:none" (change)="uploadFile(i, $event)">
              <button (click)="browseFile()" style="float: left; border: none">Choose file</button>
            </div>
            <div class="col">
            </div>
<div class="col">
          <button pButton type="button" icon="pi pi-times"
                  class="ui-button-danger action remove" (click)="onDeleteEvidence(i)"></button>
        </div>
    </div>

I want to upload a file and display file name in a specific row but every time I'm uploading a file, regardless of the div row, I get index = 0 in my method:

uploadFile(index: number, event) {
    console.log(index); // always 0 !!!
    this.fileToUpload = event.target.files.item(0);
    this.evidences[index] = {file: this.fileToUpload, publishedDate: new Date(), docTagId: 234} as IEvidence;
  }


onDeleteEvidence(index: number) {
console.log(index); //works correctly!
    this.evidences.splice(index, 1);
  }

  browseFile() {
    document.getElementById('file').click();
  }

fileExists(evidence: IEvidence): boolean {
    return !(evidence.file === undefined || evidence.file === null);
  }

What is wrong with my code?

Answer 1

Please, modify you template as follows:

<div class="row" *ngFor="let evidence of evidences; let i = index">

For your update and comments, pay attention also to your browseFile function, the problem is there: you are getting your files by id, but all of your files have the same id. Try something like:

<input type='file' id="file{{i}}" style="display:none" (change)="uploadFile(i, $event)">
<button (click)="browseFile(i)" style="float: left; border: none">Choose file</button>

And:

browseFile(i) {
    document.getElementById('file'+i).click();
  }

In fact, with these changes you can get rid of the index argument in your uploadFile function.

Answer 2

Your *ngFor is wrong. You have to adapt your index at the end:

<div class="row" *ngFor="let evidence of evidences; let i = index">