主题：[求助]代码出错，到类型"double"的转换无效（已解决）

一段代码，提取上个月月底的累计兑现列的值，代码运行出错，请各位老师指教如何修改代码，谢谢！！

代码如下：

'绩效奖_累计已兑_DataColChanged
Select Case e.DataCol.Name
    Case "日期","单位","绩效奖_累计兑现","核算标准"
        Dim dr As DataRow = e.DataRow
        Dim mydate As Date = dr("日期")
        Dim y As Integer = mydate.Year
        Dim m As Integer = mydate.Month
        If m <> 1 Then
            Dim m1 As Integer = m - 1
            Dim Days As Integer = Date.DaysInMonth(y,m1)
            Dim syd As Date = New Date(y,m1,Days) '上月月底日期
            If dr.IsNull("日期") OrElse dr.IsNull("单位") OrElse dr("绩效奖_累计兑现") = 0 Then
                dr("绩效奖_累计已兑") = 0
            Else
                dr("绩效奖_累计已兑") = " '" & dr("绩效奖_累计兑现") & "' And 单位 = '" & dr("单位") & "'And 日期 =# '" & syd & "'#"
            End If
            dr("绩效奖_累计已兑") = 0
    End If
End Select