vue methods方法互相调用，this.data数据赋值问

写一个px,vw互相转换小工具碰到的问题。记录一下
html 代码

<div id="app">
      <div>图片宽度<input type="number" v-model.number="imgWidth">px  
        <span class="left">图片高度<input type="number" v-model.number="imgHeight"> px</span> 
      </div><br>
      <div>宽度  <input type="number" v-model="pxWidth">px   
        <span class="left">宽度<input type="number" v-model.number="vwResult"> vw</span></div><br>
      <div>高度  <input type="number" v-model="pxHeight">px   
        <span class="left">高度<input type="number" v-model.number="vhResult"> vh</span></div><br>
  </div>

关键javascrip

methods: {
        //生成vw和vh通用方法
        computeV(img,px,key){
          console.log("各种this",img,px,key);
          percent = img / 100;
          key = px / percent;
          console.log("结果key",key);
          return key;
        },
        //生成px通用方法
        computeP(img,v){
          temp = img / 100;
          cache = temp * v;
          console.log("缓存",cache);
          return cache;
        }
    },
watch: {
        pxWidth(val,oldVal){
          //刚开始计算vw的写法
          // vw = this.imgWidth / 100
          // vwResult = this.pxWidth / vw;
          // this.vwResult = vwResult;
          //传过去的参数其实只是把数值传了过去，
          //并没有把this.vwResult传过去,导致没有成功修改数据(小小问题困扰好久)
          this.vwResult = app.computeV(this.imgWidth,this.pxWidth,this.vwResult);
          //也可以用下面的方法写
          // this.$options.methods.computeV(this.imgWidth,this.pxWidth,this.vwResult);
        },
        pxHeight(val,oldVal){
          this.vhResult = app.computeV(this.imgHeight,this.pxHeight,this.vhResult);
        },
        vwResult(val,lodVal){
          //刚开始计算px的写法
          // vw = this.imgWidth / 100;
          // pxWidth = vw * this.vwResult;
          // if(this.pxWidth == pxWidth){
          //    console.log("相等的");
          // }else{
          //   this.pxWidth = pxWidth;
          // }

          // this.pxWidth = app.computeP(this.imgWidth,this.vwResult,this.pxWidth);
          //进行判断是为了解决重复赋值的问题
          let temp = app.computeP(this.imgWidth,this.vwResult);
          if(this.pxWidth == temp){
            console.log("执行这里");
          }else{
            this.pxWidth = temp;
          }
        },
        vhResult(val,lodVal){
          let temp = app.computeP(this.imgHeight,this.vhResult);
          if(this.pxHeight == temp){
            console.log("执行这里");
          }else{
            this.pxHeight = temp;
          }
        }
      }