Question

使用I如果我試圖改變基於條件的圖像控制的圖像URL裏面下面的GridView是我的標記：

<asp:TemplateField HeaderText="Status"> 
    <ItemTemplate> 
     <asp:Image ID="Image1" runat="server" 
      ImageUrl='<%# IIf(CDate(Eval("startdate")) < CDate(Eval("expdate")),"~/iWebmallManager/Images/bullet_red.png", 
       "~/iWebmallManager/Images/bullet_green.png" %>' 
     /> 
    </ItemTemplate>             
    <HeaderStyle HorizontalAlign="Left" /> 
    <ItemStyle HorizontalAlign="Center" VerticalAlign="Middle" /> 
</asp:TemplateField> 

的IIF語句沒有工作。我不知道我在做什麼的權利，請幫助

Answer 1

你應該做的是在codebehind，因爲它增加了可讀性，更容易調試：

Sub GridView1_RowDataBound(ByVal sender As Object, ByVal e As GridViewRowEventArgs) 
    If e.Row.RowType = DataControlRowType.DataRow Then 
     Dim rowView = DirectCast(e.Row.DataItem,DataRowView) 
     Dim Image1 = DirectCast(e.Row.FindControl("Image1"),Image) 
     Dim startdate = DirectCast(rowView("startdate"), Date) 
     Dim expdate = DirectCast(rowView("expdate"), Date) 
     If startDate < expdate 
      Image1.ImageUrl = "~/iWebmallManager/Images/bullet_red.png" 
     Else 
      Image1.ImageUrl = "~/iWebmallManager/Images/bullet_green.png" 
     End If 
    End If 
End Sub