Extjs afteredit 怎么修改数量另一列的多单位数量也跟着改变

BID_MaterialInvitation_DetailColum.push({header: '数量',width: 120,dataIndex: 'Num',sortable:true,editor: {xtype: 'numberfield',maxLength:19,allowBlank:false,decimalPrecision:4},align: 'right'});

    BID_MaterialInvitation_DetailColum.push({header: '多单位数量',width: 120,dataIndex: 'Mult_num',align: 'left',sortable:true,editor: {xtype: 'numberfield',maxLength:19,allowBlank:false,decimalPrecision:4}});

这是两列的代码

起id，然后Ext.getCmp('id').setValue('xxxxxx')