WXML代码如下
<van-tag type="danger" size="large" Position="center">请选取猪的身长（cm）</van-tag>
<input bindchange="getlength" class='input-radius' type="text" placeholder="请在此输入身长数据" placeholder-class="phcolor" />
<van-divider />
<van-tag type="danger" size="large" Position="center">请选取猪的体重（KG）</van-tag>
<input  bindchange="getweight" class='input-radius' type="text" placeholder="请在此输入体重数据" placeholder-class="phcolor" />
<van-divider />
<button bindtap="baogu" bindtap="dadou" bindtap="xiaomai" bindtap="dami" bindtap="xsd" bindtap="yan" >点击进行饲料配比（单位均为克）</button>
<text>苞谷（玉米）需要量：{{baoguweb}}</text>


<van-divider />
<text>小麦需要量：{{xiaomaiweb}}</text>
<van-divider />
<text>大米（稻米）需要量：{{damiweb}}</text>
<van-divider />
<text>小苏打（碳酸氢钠）需要量：{{xsdweb}}</text>
<van-divider />
<text>盐需要量：{{yanweb}}</text>
<van-divider />



JS代码如下：
var length,weight,baogu,dadou,xiaomai,dami,xsd,yan
Page({
  data: {
       baoguweb:"",
       dadouweb:"",
       xiaomaiweb:"",
       damiweb:"",
       xsdweb:"",
       yanweb:""
  },
getlength:function(event){
  length=event.detail.value
  console.log(length)
},
getweight:function(event){
  weight=event.detail.value
  console.log(weight)
},

baogu,dadou,xiaomai,dami,xsd,yan:function(event){
  if (length<70)  {
    baogu=Math.round(weight*1000*(0.5)*(0.2))
    dadou=Math.round(0)
    xiaomai=Math.round(weight*1000*(0.5)*(0.0225))
    dami=Math.round(weight*1000*(0.5)*(0.15))
    xsd=Math.round(weight*1000*(0.5)*(0.005))
    yan=Math.round(weight*1000*(0.5)*(0.0025))
    console.log(baogu)
    console.log(dadou)
    console.log(xiaomai)
    console.log(dami)
    console.log(xsd)
    console.log(yan)
    console.log(length)
  }
  else if (length>70&&length<120) {
    baogu=Math.round(weight*1000*(0.4)*(0.175))
    dadou=Math.round(0)
    xiaomai=Math.round(weight*1000*(0.4)*(0.0525))
    dami=Math.round(weight*1000*(0.4)*(0.125))
    xsd=Math.round(weight*1000*(0.4)*(0.005))
    yan=Math.round(weight*1000*(0.4)*(0.0025))
      console.log(baogu)
      console.log(dadou)
      console.log(xiaomai)
      console.log(dami)
      console.log(xsd)
      console.log(yan)
    }
  else if(length>120){
    baogu=Math.round(weight*1000*(0.35)*(0.15))
    dadou=Math.round(0)
    xiaomai=Math.round(weight*1000*(0.35)*(0.04))
    dami=Math.round(weight*1000*(0.35)*(0.10))
    xsd=Math.round(weight*1000*(0.35)*(0.005))
    yan=Math.round(weight*1000*(0.35)*(0.0025))
    console.log(baogu)
    console.log(dadou)
    console.log(xiaomai)
    console.log(dami)
    console.log(xsd)
    console.log(yan)
    console.log(length)
  }
  this.setData({
    baoguweb:baogu,
    dadouweb:dadou,
    xiaomaiweb:xiaomai,
    damiweb:dami,
    xsdweb:xsd,
    yanweb:yan,
    })
},
})