PROSAGA码农传奇-雾计算/网格计算-事件位于网格中ActiveEditor的DataSource更新后

事件位于网格中ActiveEditor的DataSource更新后

作者: Charizard
发布时间: 2024-08-18 03:57:58 (18天前)
转自：

<div class =“post-text”itemprop =“text”>
  <BLOCKQUOTE>
    
      ...我需要做的是根据网格中其他字段的值计算网格中一个字段的值。
    
  </BLOCKQUOTE>
  
    完成此任务的最佳方法是使用
    <a href="http://help.devexpress.com/#WindowsForms/CustomDocument1477" rel="nofollow">
      未绑定的列
    </A>
     特征。
  
  
    以下示例演示如何通过处理实现此功能
    <a href="http://help.devexpress.com/#WindowsForms/DevExpressXtraGridViewsBaseColumnView_CustomUnboundColumnDatatopic" rel="nofollow">
      ColumnView.CustomUnboundColumnData
    </A>
     事件：
  
   <pre>
 <code>
 // Provides data for the Total column.
void gridView1_CustomUnboundColumnData(object sender, CustomColumnDataEventArgs e) {
 if (e.Column.FieldName == "Total" && e.IsGetData) e.Value = 
 getTotalValue(e.ListSourceRowIndex);
}
// Returns the total amount for a specific row.
decimal getTotalValue(int listSourceRowIndex) {
 DataRow row = nwindDataSet.Tables["Order Details"].Rows[listSourceRowIndex];
 decimal unitPrice = Convert.ToDecimal(row["UnitPrice"]);
 decimal quantity = Convert.ToDecimal(row["Quantity"]);
 decimal discount = Convert.ToDecimal(row["Discount"]);
 return unitPrice * quantity * (1 - discount);
}

</code>
 </pre>
  
    原始示例：
    <a href="http://help.devexpress.com/#WindowsForms/CustomDocument3008" rel="nofollow">
      如何：添加存储任意数据的未绑定列
    </A>
  
  
    您还可以使用实现未绑定列的计算值
    <a href="http://help.devexpress.com/#WindowsForms/CustomDocument6211" rel="nofollow">
      表达式
    </A>
    ：
  
   <pre>
 <code>
 GridColumn columnTotal = new GridColumn();
columnTotal.FieldName = "Total";
columnTotal.Caption = "Total";

columnTotal.UnboundType = DevExpress.Data.UnboundColumnType.Decimal;
columnTotal.UnboundExpression = "[Quantity] * [UnitPrice] * (1 - [Discount])";

gridView1.Columns.Add(columnTotal);

</code>
 </pre>
</DIV>