upload img angular ngzorro zorro image

ex.ts

//HTML
<div>
  <nz-upload nzType="drag" [nzBeforeUpload]="beforeUpload" [nzLimit]="1" nzAccept="image/*" nzFIleType="image/*" [nzData]="img"
    [nzShowUploadList]="false" [hidden]="disableUpload">
    <h2>Subir Flyer</h2>
    <p class="ant-upload-drag-icon" *ngIf="!disableUpload">
      <i nz-icon type="upload" theme="outline"></i>
    </p>
    <p class="ant-upload-text" *ngIf="!disableUpload">Click o arrastre la foto a esta zona para subir</p>
  </nz-upload>
  <div *ngIf="disableUpload">
    <div nz-row>
      <div nz-col [nzSpan]="22">
        <img style="width: 100%;" [src]="flyer" alt="">
      </div>
      <div nz-col [nzSpan]="2">
        <button nz-button nzType="default" nzShape="circle" (click)="deleteFile()" class="delete"><i class="anticon anticon-delete"></i></button>
      </div>
    </div>
  </div>
</div>

// TS

 //vars:
 flyer: any;
  disableUpload: boolean
  //function
beforeUpload = (file): boolean => {
    var reader = new FileReader();
    reader.onloadend = () => {
      this.flyer = reader.result;
      if(this.flyer) this.disableUpload = true;
			console.log('TCL: EventoNuevoComponent -> reader.onloadend -> this.flyer', this.flyer)
    }
    reader.readAsDataURL(file);
    return false;
  }

  deleteFile() {
    this.disableUpload = false;
  }