element-ui table合计功能以及改变字段样式

    <el-table :data="tableData" style="width: 100%;margin-bottom: 20px;" row-key="id" border stripe
                      default-expand-all
                      //这是合计功能
                      show-summary
                      :summary-method="getTotal"
                      //这是样式列表
                      :cell-style="needStyle"
                      v-loading="loading">

合计功能和样式列表都需要绑定对应method
合计的方法getTotal

  getTotal(param) {
                const { columns, data } = param;
                const sums = [];
                var arr = ["test1","test2","test3","test4"];
             
                columns.forEach((column, index) => {
                    if (index === 0) {
                        sums[index] = '合计';
                        return;
                    }
                    const values = data.map(item => Number(item[column.property]));
                    if (arr.indexOf(column.property)!==-1) {
                        sums[index] = values.reduce((prev, curr) => {
                            const value = Number(curr);
                            if (!isNaN(value)) {
                                return prev + curr;
                            } else {
                                return prev;
                            }
                        }, 0);
                    } else {
                        sums[index] = '--';
                    }
                });

                return sums;
            },

样式的方法needStyle

 needStyle: function(column){
                let cellStyle;
                switch (column.column.property) {
                    case 'test1':
                        cellStyle = 'color:red';
                        break;
                    case 'test2':
                        cellStyle = 'color:red';
                        break;
                    case 'test3':
                        cellStyle = 'color:blue';
                        break;
                    default:
                        cellStyle = '';
                }
                return cellStyle;
            },