Vue+ElementUI项目笔记（四、表单+计算）

模板

<template>
 <div id='volume'>
    <el-table :data="tableData" style="width: 100%" align='center' show-summary>
        <el-table-column type="index">
        </el-table-column>
        <el-table-column label="长(cm)" property="length" align='center'>
            <template slot-scope="scope">
                <div slot="reference" >
                    <el-input size="medium" v-model="scope.row.length" ref='length'></el-input>
                </div>
            </template>
        </el-table-column>
        <el-table-column label="宽(cm)" property="width" align='center'>
            <template slot-scope="scope">
                <div slot="reference" >
                    <el-input size="medium" v-model="scope.row.width" ref='width'></el-input>
                </div>
            </template>
        </el-table-column>
        <el-table-column label="高(cm)" property="height" align='center'>
            <template slot-scope="scope">
                <div slot="reference" >
                    <el-input size="medium" v-model="scope.row.height" ref='height'></el-input>
                </div>
            </template>
        </el-table-column>
        <el-table-column label="件数" property="quantity" align='center'>
            <template slot-scope="scope">
                <div slot="reference" >
                    <el-input size="medium" v-model="scope.row.quantity" ref='quantity' @keyup.enter.native="volumeAdd(scope.$index,scope.row)">
                        
                    </el-input>
                </div>
            </template>
        </el-table-column>
        <el-table-column label="计算体积(m3)" align='center' property="volume">
            <template slot-scope="scope">
                <div slot="reference" ref='volume'>
                    <p>{{ scope.row.volume }}</p>
                </div>
            </template>
        </el-table-column>
        <el-table-column label="计算重量(kg)" align='center' property="volume_weight">
            <template slot-scope="scope">
                <div slot="reference" >
                    <p>{{ scope.row.volume_weight }}</p>
                </div>
            </template>
        </el-table-column>
        <el-table-column label="操作" align='center'>
          <template slot-scope="scope">
            <el-button
              size="mini"
              type="danger"
              @click="handleDelete(scope.$index, scope.row)">删除</el-button>
          </template>
        </el-table-column>
    </el-table>
</div>
</template>

交互

<script>
    引入计算插件
   const {Decimal} = require("../../utils/count.js")
   export default {
name: 'volume',
data() {
    return {
        tableData: [{
            
        }],
        getLength:null,
    }
},
methods: {
    handleDelete(index, row) {
        console.log(index, row);
        if(this.tableData.length > 1){
            this.tableData.splice(index, 1);
        }
        
    },
    回车事件
    volumeAdd:function(index,row){
        获取长、宽、高、件数、体积、重量的value值
        this.dataList = {
            length:this.$refs.length.value,
            width:this.$refs.width.value,
            height:this.$refs.height.value,
            quantity:this.$refs.quantity.value,
            volume:'',
            volume_weight:''
        };
                   
        let {length:l, width:w, height:h, quantity:n} = this.dataList;
         if(l && w && h && n){
            计算体积
            this.dataList.volume = Decimal.add(1).mul(l).mul(w).mul(h).mul(n).div(1000000).toNumber()
            计算重量        
            this.dataList.volume_weight = Math.round(Decimal.add(1).mul(l).mul(w).mul(h).mul(n).div(6000).toNumber())
            输入体积        
            row.volume = this.dataList.volume
            输入重量
            row.volume_weight = this.dataList.volume_weight
            
        }
        最后一条数据回车时添加一条数据
        if(index == this.tableData.length-1){
            this.tableData.push(
                {
                    length: '',
                    width: '',
                    height: '',
                    piece: '',
                    volume:'',
                    volume_weight:''
                }
            )
        }
     }
  }
}
</script>

count.js计算插件

  /** 小数计算 
  * @example: 
  * 0.1+0.2     //0.30000000000000004 
  * var a=Decimal('0.1');var b=Decimal('0.2'); 
  * a.add(b).toNumber()    //0.3 
  * 四舍五入，保留一位小数 
  * a.add(b).add(0.14).toNumber(1)  //0.4 
  * Decimal.add(0.1,0.2,0.3).toNumber()  //0.6 
  * Decimal.add([0.1,0.2,0.3]).toNumber()  //0.6 
  * (0.1+0.2+0.3)*2/0.5      //2.4000000000000004 
   * Decimal.add([0.1,0.2,0.3]).mul(2).div(0.5).toNumber() //2.4 
    * */

(function (ROOT, factory) {
if (typeof exports === 'object') {
// Node.  
module.exports = factory();
} else if (typeof define === 'function' && define.amd) {
// AMD. Register as an anonymous module.  
define(factory);
} else {
// Browser globals (root is window)  
ROOT.Decimal = factory();
}
 }((0, eval)(this), function () {
  var DECIMAL_SEPARATOR = '.';

  // Decimal  
    var Decimal = function (num) {
if (!this || this.constructor != Decimal) {
  return new Decimal(num);
}

if (num instanceof Decimal) {
  return num;
}

this.internal = String(num);
this.as_int = as_integer(this.internal);

this.add = function (target) {
  var operands = [this, new Decimal(target)];
  operands.sort(function (x, y) {
    return x.as_int.exp - y.as_int.exp
  });

  var smallest = operands[0].as_int.exp;
  var biggest = operands[1].as_int.exp;

  var x = Number(format(operands[1].as_int.value, biggest - smallest));
  var y = Number(operands[0].as_int.value);

  var result = String(x + y);

  return Decimal(format(result, smallest));
};

this.sub = function (target) {
  return Decimal(this.add(target * -1));
};

this.mul = function (target) {
  target = new Decimal(target);
  var result = String(this.as_int.value * target.as_int.value);
  var exp = this.as_int.exp + target.as_int.exp;

  return Decimal(format(result, exp));
};

this.div = function (target) {
  target = new Decimal(target);

  var smallest = Math.min(this.as_int.exp, target.as_int.exp);

  var x = Decimal.mul(Math.pow(10, Math.abs(smallest)), this);
  var y = Decimal.mul(Math.pow(10, Math.abs(smallest)), target);
  return Decimal(x / y);
};

this.toString = function (precision) {
  if (isNumber(precision)) {
    return '' + toFixed(Number(this.internal), precision);
  }
  return this.internal;
};

this.toNumber = function (precision) {
  if (isNumber(precision)) {
    return toFixed(Number(this.internal), precision);
  }
  return Number(this.internal);
}
};

var as_integer = function (number) {
number = String(number);

var value,
  exp,
  tokens = number.split(DECIMAL_SEPARATOR),
  integer = tokens[0],
  fractional = tokens[1];

if (!fractional) {
  var trailing_zeros = integer.match(/0+$/);

  if (trailing_zeros) {
    var length = trailing_zeros[0].length;
    value = integer.substr(0, integer.length - length);
    exp = length;
  } else {
    value = integer;
    exp = 0;
  }
} else {
  value = parseInt(number.split(DECIMAL_SEPARATOR).join(''), 10);
  exp = fractional.length * -1;
}

return {
  'value': value,
  'exp': exp
};
};


 // Helpers  
var neg_exp = function (str, position) {
position = Math.abs(position);

var offset = position - str.length;
var sep = DECIMAL_SEPARATOR;

if (offset >= 0) {
  str = zero(offset) + str;
  sep = '0.';
}

var length = str.length;
var head = str.substr(0, length - position);
var tail = str.substring(length - position, length);
return head + sep + tail;
};

 var pos_exp = function (str, exp) {
var zeros = zero(exp);
return String(str + zeros);
};

 var format = function (num, exp) {
num = String(num);
var func = exp >= 0 ? pos_exp : neg_exp;
return func(num, exp);
 };

 var zero = function (exp) {
return new Array(exp + 1).join('0');
 };

  var methods = ['add', 'mul', 'sub', 'div'];
 for (var i = 0; i < methods.length; i++) {
(function (method) {
  Decimal[method] = function () {
    var args = [].slice.call(arguments);
    if (isArray(args[0])) {
      args = args[0];
    }
    if (args.length == 1) {
      return new Decimal(args[0]);
    }
    var option = args[args.length - 1];

    var sum = new Decimal(args[0]),
      index = 1;
    while (index < args.length) {
      sum = sum[method](args[index]);
      index++;
    }
    return sum;
  };
})(methods[i]);
 }

 var toFixed = function (number, precision) {
var multiplier = Math.pow(10, precision + 1),
  wholeNumber = Math.floor(number * multiplier);
return Math.round(wholeNumber / 10) * 10 / multiplier;
  };
 var isNumber = function (o) {
return Object.prototype.toString.call(o).slice(8, -1) === 'Number';
 };
  var isArray = function (o) {
return Object.prototype.toString.call(o).slice(8, -1) === 'Array';
  };
var isObject = function (o) {
return Object.prototype.toString.call(o).slice(8, -1) === 'Object';
 };
return Decimal;
 }));