EasyNVR通道关闭水印报错Cannot read properties of undefined

onSubmit() {
  var _this = this;
  var formdata = new FormData();
  if (Number(this.watermarkData.enable) === 0){
    formdata.append("channelId", this.channelData.Channel);
    formdata.append("enable", Number(this.watermarkData.enable));
  }else{
    let { w, mw, h, mh, id } = this.orientation;
    let width = 0;
    let height = 0;
    let mwl = (w / mw)>=701?mw+1:mw;
    let mhl = (h / mh)>=701?mw+1:mw;
    width = w / mwl - this.transform.width;
    height = h / mhl - this.transform.height;
    this.transform = {
      X: this.transform.x * mwl,
      Y: this.transform.y * mhl,
      Width: this.transform.width * mwl,
      Height: this.transform.height * mhl,
    }
  }