CODEWITHSUNDEEP
c#asp.net.net
user1266515
user1266515

Reputation: 796

Dropdown box chained filters not working?

I am trying to implement a simple filter from one dropdown box to another.

The second dropdown box deos not populate (with any item) when I select an item from the first dropdown. I am not sure what I am missing. Please advise.

Here is the ascx code:

  <div id="SubmitSection" style="width:auto; height:auto;" class="SubmitSectionStyle">
        <div id="DropdownSection" style="text-align:center;">
        <asp:DropDownList ID="DropDown1" runat="server" AppendDataBoundItems="true"
               onselectedindexchanged="Type_SelectedIndexChanged" ToolTip="Select Category">
              <asp:ListItem Text="--Select Category--" Value="" />
              <asp:ListItem Value="1">Department</asp:ListItem>
              <asp:ListItem Value="2">Safety</asp:ListItem>
        </asp:DropDownList>&nbsp;

        <asp:DropDownList ID="DropDown2" runat="server">
        <asp:ListItem Text="--Select One--" Value="" />
        </asp:DropDownList>

      </div>

And here is my code behind:

protected void Type_SelectedIndexChanged(object sender, EventArgs e)
    {
        if (DropDown1.SelectedValue == "1")
        {
            DropDown2.Items.Clear();
            DropDown2.Items.Add("DeptTest");
            DropDown2.DataBind();
        }
        else if (DropDown1.SelectedValue == "2")
        {
            DropDown2.Items.Clear();
            DropDown2.Items.Add("SafetyTest");
            DropDown2.DataBind();
        }
    }

Upvotes: 0

Views: 319

Answers (3)

nunespascal
nunespascal

Reputation: 17724

You need to set auto postback to true if you want it to update the page on item change.

<asp:DropDownList ID="DropDown1" AutoPostBack="True" runat="server" AppendDataBoundItems="true" onselectedindexchanged="Type_SelectedIndexChanged" ToolTip="Select Category" >
              <asp:ListItem Text="--Select Category--" Value="" />
              <asp:ListItem Value="1">Department</asp:ListItem>
              <asp:ListItem Value="2">Safety</asp:ListItem>
        </asp:DropDownList>

You might also want to consider wrapping both these DropDownList controls in an update panel, so that you don't refresh the whole page every time a user changes a selection.

Upvotes: 1

Waqar Janjua
Waqar Janjua

Reputation: 6123

AutoPostBack = "true" // AutoPostBack attribute is missing in DropDown1 due to which the event does not fire

// change your dropdown1 code as
<asp:DropDownList ID="DropDown1" AutoPostBack = "true" runat="server" AppendDataBoundItems="true"
           onselectedindexchanged="Type_SelectedIndexChanged" ToolTip="Select Category">
          <asp:ListItem Text="--Select Category--" Value="" />
          <asp:ListItem Value="1">Department</asp:ListItem>
          <asp:ListItem Value="2">Safety</asp:ListItem>
    </asp:DropDownList>

Upvotes: 1

CodingSlayer
CodingSlayer

Reputation: 915

In your first dropdownlist, set AutoPostBack="True"

Upvotes: 1

Related Questions