Angular 5 手动设置反应形式的错误未反映在 dom (IE/IOS)

Question

我正在使用 angular 5 反应形式。因为我有一个浏览字段，在该浏览按钮的更改事件中我正在调用一个函数，在该文件验证中进行检查。如果文件无效，我将手动为该字段设置错误。

现在我期待的是设置文件输入错误。错误消息应显示在 DOM 中。它在 Chrome、Firefox 和 Android 设备上运行良好。但它在 IE 和 IOS.

中不起作用

HTML 代码

<div class="form-group" [ngClass]="{'has-error': hasError('profileimage')}">
   <label class="control-label"> Upload Profile Image...</label>
   <input id="profileimage" 
   (change)="fileUpload($event.target.files,'profileimage')" 
   type="file"
   formControlName="profileimage">
   <span class="is-error" *ngIf="checkValidImageFormat('profileimage')">
   Only file with extensions are allowed: .png, .jpeg, .jpg .</span>
   <span class="is-error" *ngIf="checkValidImageSize('profileimage')">File must be less than 1 MB .
   </span>
 </div>

Component.ts

fileUpload(files: FileList, field) {
  this.profileimage = files[0];
  let extension = this.profileimage.name.match(/(?:\.([^.]+))?$/)[1];
  //checking the extension of the file
  if (extension.toLowerCase() === 'jpg' ||
    extension.toLowerCase() === 'jpeg' ||
    extension.toLowerCase() === 'png') {

    var sizeInMB = (this.profileimage.size / (1024 * 1024)).toFixed(2);
    //checking the file size should be less than 1 mb
    if (!parseFloat(sizeInMB) < 1) {
      this.contactForm.controls[field].setErrors({ 'invalid_size': true });
  }
}

checkValidImageSize(fieldName) {
  return this.contactForm.controls[fieldName].errors.invalid_size;
}

我已经为 angular 尝试了所有变更检测策略（NgZone、ChangeDetectorRef 等），但其中 none 有效。任何帮助将不胜感激。

Answer 1

您可以创建属性指令，例如...

html（必须遵循 html 标签的顺序）

 <div class="form-group">
    <label class="control-label"> Upload Profile Image...</label>
    <input id="profileimage" checkinvalid (change)="fileUpload($event.target.files,'profileimage')" type="file"
      formControlName="profileimage">
    <span class="is-error">File must be less than 1 MB .</span>
    <span class="is-error">Only file with extensions are allowed: .png, .jpeg, .jpg .</span>
  </div>

component.ts（没有必要，因为您已经在表单控件中获得了值）

fileUpload(files: FileList, field) {
    this.profileimage = files[0];
}

directive.ts

parent: any;
spanForFormat: any;
spanForSize: any;

@HostListener('change', ['$event'])
handleChangeEvent(event) {
    const file = event.target.files[0];
    this.checkInvalid(file);
}

constructor(private elementRef: ElementRef, private renderer: Renderer2) { }

ngOnInit() {
    this.parent = this.elementRef.nativeElement['parentElement'];
    this.spanForSize = this.elementRef.nativeElement['parentElement'].children[2];
    this.spanForFormat = this.elementRef.nativeElement['parentElement'].children[3];
    this.renderer.addClass(this.spanForSize, 'hidden');
    this.renderer.addClass(this.spanForFormat, 'hidden');
}

private checkInvalid(file) {

    this.renderer.addClass(this.spanForSize, 'hidden');
    this.renderer.addClass(this.spanForFormat, 'hidden');
    this.renderer.removeClass(this.parent, 'has-error');

    let extension = file.name.match(/(?:\.([^.]+))?$/)[1];
    let sizeInMB = (file.size / (1024 * 1024)).toFixed(2);

    if (!(extension.toLowerCase() === 'jpg' ||
        extension.toLowerCase() === 'jpeg' ||
        extension.toLowerCase() === 'png')) {
        this.renderer.removeClass(this.spanForFormat, 'hidden');
        this.renderer.addClass(this.parent, 'has-error');
    }

    if (!(parseFloat(sizeInMB) < 1)) {
        this.renderer.removeClass(this.spanForSize, 'hidden');
        this.renderer.addClass(this.parent, 'has-error');
    }
}

Angular 5 手动设置反应形式的错误未反映在 dom (IE/IOS)

Angular 5 manually set Error in reactive form is not reflecting on dom (IE/IOS)

javascript

angular

angular-reactive-forms