在VB.Net Gridview中添加总计

时间:2013-09-16 12:51:56

标签: asp.net vb.net gridview footer

我无法让网格视图显示页脚中的总数

我尝试了以下内容:

<asp:GridView ID="GV" runat="server" 
    DataSourceID="SqlQuery" EmptyDataText="No data">
    <Columns>
        <asp:BoundField DataField="Weekday" FooterText=" " HeaderText="Weekday" />
        <asp:BoundField DataField="Volume" DataFormatString="{0:N0}" 
            FooterText="." HeaderText="Volume" />            
    </Columns>
 </asp:GridView>


Protected Sub GV_rowdatabound(sender As Object, e As GridViewRowEventArgs) Handles GV.RowDataBound
    Dim Volume as integer = 0
    For Each r As GridViewRow In GV.Rows
        If r.RowType = DataControlRowType.DataRow Then
            Volume = Volume + CDec(r.Cells(1).Text)
        End If
    Next
    GV.FooterRow.Cells(1).Text = Math.Round(Volume , 0)
End Sub

这给了我一条错误消息:

对象引用未设置为对象的实例

我按照以下页面中的建议修改了代码: trying to total gridview in asp

Sub GV_WeekSumary_rowcreated(ByVal sender As Object, ByVal e As GridViewRowEventArgs)
    Dim Volume as integer = 0
    For Each r As GridViewRow In GV.Rows
        If r.RowType = DataControlRowType.DataRow Then
            Volume = Volume + CDec(r.Cells(1).Text)
        End If
    Next

    If e.Row.RowType = DataControlRowType.Footer Then
        e.Row.Cells(1).Text = Math.Round(Volume , 0)
    End If
End Sub

这不会出错,但页脚没有显示任何值。

我也尝试了以下内容:

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
    Dim Volume as integer = 0
    For Each r As GridViewRow In GV.Rows
        If r.RowType = DataControlRowType.DataRow Then
            Volume = Volume + CDec(r.Cells(1).Text)
        End If
    Next
    GV.FooterRow.Cells(1).Text = Math.Round(Volume, 0)
    GV.DataBind()
End Sub

页脚中仍然没有任何价值,但是当我对它进行调查时,我可以看到该页脚被分配了我需要的价值。为什么它没有显示在网站上?

知道如何才能让它发挥作用吗?

1 个答案:

答案 0 :(得分:2)

您必须使用 DataBound 事件。

试试这个:

Protected Sub GV_DataBound(ByVal sender As Object, ByVal e As System.EventArgs) Handles GV.DataBound
    Dim Volume As Decimal = 0
    For Each r As GridViewRow In GV.Rows
        If r.RowType = DataControlRowType.DataRow Then
            Volume += Convert.ToDecimal(r.Cells(1).Text)
        End If
    Next
    GV.FooterRow.Cells(1).Text = Math.Round(Volume, 0).ToString()
End Sub