Using Methods in Serverside ControlIDs

Question

i got the following code on my ASP-Site

<asp:Repeater runat="server" ID="repFoo">
<ItemTemplate>
    <asp:Button runat="server" ID="btnfoo" Visible='<%#!String.IsNullOrEmpty("FOOValue")%>' />
</ItemTemplate>
</asp:Repeater>

how is the correct syntax for the String.IsNullOrEmpty method?

Answer 1

there are 2 ways :

declare function in your cs file that get the value and make your checks on it:

<asp:Button runat="server" ID="btnfoo" Visible='<%# CheckNull(Eval("FOOValue")) %>' />

public bool CheckNull(object value)
{
    return string.IsNullOrEmpty(value) ? fale : true;
}

OR use the function IsNullOrEmpty inline :

<asp:Button runat="server" ID="btnfoo" Visible='<%# String.IsNullOrEmpty(Eval("FOOValue").ToString()) ? false : true %>' />