以编程方式在ASPX页面中设置'visible'属性的值

Question

I am trying to set the visible property for a label to either true or false depending on a condition. This is in ASPX page. I am doing something wrong and getting error when this is executed.

<td><asp:Label ID="Label23" runat="server" Text='CERTIFIED'
   Visible='<%# DataBinder.Eval(Container.DataItem, "IsAuthorized") > 0%>'>
</asp:Label></td>

Error I am getting is below.

Compiler Error Message: CS0019: Operator '>' cannot be applied to operands of type 'object' and 'int'

What changes need to be done?

All I need to do set the visible property of the LABEL to true when 'IsAuthorized' is greater than zero.

Answer 1

That's because you have a syntax error, you silly bunny.

Here you are, it should be like this:

 <td><asp:Label ID="Label23" runat="server" Text='CERTIFIED' Visible='<%# DataBinder.Eval(Container.DataItem, "IsAuthorized") %>'  /></td>

You had an extra > and a 0 in there somewhere. Also, since you aren't doing anything between the <asp:Label and </asp:Label> , you can close it with an end slash and skip a separate ending tag. Like this <asp:Label ... />

ALSO, sometimes trying to set a visible property like that causes problems, the program can complain that the value wasn't a Boolean. You might want to also ad an explicit conversion like this:

 Visible='<%# Convert.ToBoolean(DataBinder.Eval(Container.DataItem, "IsAuthorized")) %>' 

Answer 2

假设IsAuthorized是一个位类型，只需将其IsAuthorized转换为布尔值：

 Visible='<%#Convert.ToBoolean(Eval("IsAuthorized"))%>'  

Answer 3

Note on a server side control you can do this:

<someControl id="myId" runat="server" Visible='<%# this.SomeField > 5 %>'>

But it won't work unless you call DataBind in the code behind, such as in Page_Load:

myId.DataBind():

Answer 4

Assuming IsAuthorized is an integer, you should use this:

Visible='<%# ((int)DataBinder.Eval(Container.DataItem, "IsAuthorized")) > 0 %>'

Eval returns an object , so you have to cast it to an integer first.

Answer 5

<td><asp:Label ID="Label23" runat="server" Text='CERTIFIED' Visible='<%# (int)(DataBinder.Eval(Container.DataItem, "IsAuthorized")) > 0 %>' ></asp:Label></td>