I have two dropdowns categories and subcategories on my page. Also I have an htmleditor on the same page. Below is my aspx
<div class="clearfx">
</div>
<div>
<label>
Description :
</label>
<div style="padding-left: 10px; margin-left: 146px;">
<cc:HtmlEditor ID="Editor" runat="server" Height="600px" Width="850px" EnableViewState="true" />
</div>
</div>
<div class="clearfx">
</div>
<div>
<asp:UpdatePanel runat="server" ID="up" UpdateMode="Always" ChildrenAsTriggers="true">
<ContentTemplate>
<label>Category : </label>
<asp:DropDownList runat="server" ID="Categories" Width="200px" AutoPostBack="True"
OnSelectedIndexChanged="CategoriesSelectedIndexChanged">
</asp:DropDownList>
<asp:RequiredFieldValidator ID="rfvCountry" runat="server" ErrorMessage="Choose a category."
ControlToValidate="Categories" Display="None" EnableTheming="False" EnableViewState="False"
InitialValue="-1" SetFocusOnError="True" ValidationGroup="grpReg"></asp:RequiredFieldValidator>
<asp:ValidatorCalloutExtender ID="rfvCountry_ValidatorCalloutExtender" runat="server"
Enabled="True" TargetControlID="rfvCountry">
</asp:ValidatorCalloutExtender>
<asp:ImageButton runat="server" ID="Refresh" ImageAlign="AbsMiddle"
ImageUrl="~/cdn/images/refresh.png" onclick="RefreshClick"/>
<span class="helptext">(click on refresh image, incase subcategories do not load.)</span>
</ContentTemplate>
</asp:UpdatePanel>
</div>
<div class="clearfx">
</div>
<div>
<label>
Sub Category :
</label>
<asp:DropDownList runat="server" ID="SubCategories" Width="200px">
</asp:DropDownList>
<asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" ErrorMessage="Choose a sub category."
ControlToValidate="SubCategories" Display="None" EnableTheming="False" EnableViewState="False"
InitialValue="-1" SetFocusOnError="True" ValidationGroup="grpReg"></asp:RequiredFieldValidator>
<asp:ValidatorCalloutExtender ID="ValidatorCalloutExtender2" runat="server" Enabled="True"
TargetControlID="RequiredFieldValidator2">
</asp:ValidatorCalloutExtender>
</div>
What I am doing is that, On the selected index change of the categories dropdown i am populating subcategories. to suppress post back i am using an Update Panel, But my problem is that,the selected index change is fired but the dropdown subcategories does not gets binded. When I remove the update panel, then its works fine, but my html editor looses its value, even having its own and Page enableviewstate = true. Please help me.
My Codebehind methods are:
Dropdown Selected Index Change Event:
protected void CategoriesSelectedIndexChanged(object sender, EventArgs e)
{
if (Categories.SelectedIndex > 0)
{
BindSubCategory(Common.ParseInt(Categories.SelectedItem.Value));
}
else
{
SubCategories.SelectedIndex = 0;
SubCategories.Items.Clear();
}
}
Page Load Event:
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
BindGrid();
BindCategories();
}
}
private void BindCategories()
{
List<Category> cat = _categoryRepository.GetAll().ToList();
Common.BindDropdown(cat, Categories); // static method
}
public static class Common
{
/// <summary>
///
/// </summary>
/// <param name="list"></param>
/// <param name="ddl"></param>
public static void BindDropdown(IList list, DropDownList ddl)
{
if (list.Count>0)
{
ddl.DataSource = list;
ddl.DataTextField = "Name";
ddl.DataValueField = "Id";
ddl.DataBind();
ddl.Items.Insert(0, new ListItem("---Select---", "-1"));
}
}
}
Try this: