Javascript 按下按钮的次数应与变量（往复）值相乘

我正在开发Angular 8应用程序。我想将按下按钮的次数乘以现有值（往复）。但它没有给我正确的结果

结果应该是=>8*3=24 但是我得到的结果是=>48

谁能帮我一下吗

我的TS代码

  quantityControl(flag) {

    if (flag == '+') {
      this.quantity = this.quantity + 1;
      if (this.filteredRecipe.RecipePrice === 0) {
        this.recipeTotal = this.recipeTotal * this.quantity;
        console.log('The price is:'+ this.recipeTotal);
      }
    } else {
      if (this.quantity != 1) {
        this.quantity = this.quantity - 1;
        if (this.filteredRecipe.RecipePrice === 0) {
          this.recipeTotal = this.recipeTotal * this.quantity;
        }
      }
    }
  }

 <div class="u-line">
      <div class="product-quantity padding-10"><span class="text-light-black fw-700 fs-16">Quantity</span>
        <div class="input-group quantity">
          <div class="input-group-append">
            <button (click)="quantityControl('-')" class="minus-btn" type="button" name="button">
              <i class="fas fa-minus"></i>
            </button>
          </div>
          <input type="text" class="text-center" [(ngModel)]="quantity" name="quantity" value="1" style="font-size: 18px; font-weight: bold;">
          <div class="input-group-prepend">
            <button (click)="quantityControl('+')" class="plus-btn" type="button" name="button"><i
              class="fas fa-plus"></i>
            </button>
          </div>
        </div>
      </div>
    </div>

我的HTML代码

  quantityControl(flag) {

    if (flag == '+') {
      this.quantity = this.quantity + 1;
      if (this.filteredRecipe.RecipePrice === 0) {
        this.recipeTotal = this.recipeTotal * this.quantity;
        console.log('The price is:'+ this.recipeTotal);
      }
    } else {
      if (this.quantity != 1) {
        this.quantity = this.quantity - 1;
        if (this.filteredRecipe.RecipePrice === 0) {
          this.recipeTotal = this.recipeTotal * this.quantity;
        }
      }
    }
  }

 <div class="u-line">
      <div class="product-quantity padding-10"><span class="text-light-black fw-700 fs-16">Quantity</span>
        <div class="input-group quantity">
          <div class="input-group-append">
            <button (click)="quantityControl('-')" class="minus-btn" type="button" name="button">
              <i class="fas fa-minus"></i>
            </button>
          </div>
          <input type="text" class="text-center" [(ngModel)]="quantity" name="quantity" value="1" style="font-size: 18px; font-weight: bold;">
          <div class="input-group-prepend">
            <button (click)="quantityControl('+')" class="plus-btn" type="button" name="button"><i
              class="fas fa-plus"></i>
            </button>
          </div>
        </div>
      </div>
    </div>

量

可能是这个函数的错误

if (this.filteredRecipe.RecipePrice === 0)

---

过去的代码或自己检查。

问题在于“recipetotal”变量。当按钮单击一次时，其值将与它相乘。但当按下按钮两次或三次时。以前存储的“recipetotal”值已乘以。如果第一次按下此条件“this.filteredRecipe.RecipePrice==0”，则单击按钮后，“RecipeTotal”值会自动增加。请尝试使用控制台日志进行调试。最好检查else条件中的“this.quantity”是否不等于0，因为变量“recipetotal”在if条件中。它在控制台内给了我相同的答案，也可能是事件传播问题，请尝试使用jquery代码来防止它只捕获一次事件-->$（“按钮”）.click（function（）{$（“p”）.off（“click”）；}；