DevExpress Xtra报告:当明细栏没有任何数据时,如何在组页脚中显示标签?

此事件附加到报表本身(在我的示例中,它名为xtrareport1)。 GetCurrentRow() 是一种方法 XtraReportBase 从主报表绑定源返回当前数据。如果数据不存在,则返回空值。

private void XtraReport1_BeforePrint(object sender, PrintEventArgs e)
{
    bool noDataFound = GetCurrentRow() == null;

    lblWarning.Visible = noDataFound;
}

VB中的同一个处理程序:

Private Sub XtraReport1_BeforePrint(ByVal sender As System.Object, ByVal e As PrintEventArgs) Handles MyBase.BeforePrint
    Dim noDataFound As Boolean = GetCurrentRow() Is Nothing

    lblWarning.Visible = noDataFound
End Sub

目前还没有出现在我的开发人员机器前,不过这样的事情可能会奏效。

Dim HadRecords As Boolean = False

Private Sub GroupFooter1_BeforePrint(ByVal sender As Object, ByVal e As System.Drawing.Printing.PrintEventArgs) Handles GroupFooter1.BeforePrint
    If HadRecords = False Then
        lblWarning.visible = True
    Else
        lblWarning.visible = False
        HadRecords = False ' reset the flag '
    End If
End Sub

Private Sub Detail_BeforePrint(ByVal sender As Object, ByVal e As System.Drawing.Printing.PrintEventArgs) Handles Detail.BeforePrint
    HadRecords = True ' set the flag '
End Sub