How to change the style elements of a listview? (the simple way)

With the ASP.NET listview control, you can set an AlternatingItemTemplate in order to change the display or what you want.

If you just want to change the backcolor or things like that, you can spare some time by using only the ItemTemplate and applying a diffenrent style depending of the index (use of the Container.DataItemIndex property).

example : let’s say that your listview generate a <table> and each ItemTemplate generate a row of this table, just do :

  <tr class='<%# Container.DataItemIndex % 2 == 0 ? “normal” : “alternating” %>'>
    <td>blah blah</td>

that’s all you need !

How to use a ValidationSummary to display server errors?

Imagine you want to use your ValidationSummary to display server errors as client error, there is a simple way to do that.

First, declare your ValidationSummary, and a CustomValidator with Display property set to “None”

<asp:CustomValidator ID="ServerErrorCustomValidator"
Display="None" runat="server" ValidationGroup="MyValidationGroup" />

<asp:ValidationSummary ID="AdministrationTaskValidationSummary" runat="server" ValidationGroup="MyValidationGroup"/>

Next, in your application code, when an error occurs : set the CustomValidator’s ErrorMessage and IsValid properties :

ServerErrorCustomValidator.ErrorMessage = "Server error :  error description";
ServerErrorCustomValidator.IsValid = false;