ASP.Net DropDownList OnSelectedIndexChange not firing

Question

I have the following DropDownList control:

<asp:label runat="server" text="Filter by state: "></asp:label>
<asp:dropdownlist runat="server" id="filterbystate" 
    OnSelectedIndexChanged="FilterByState">
    <asp:ListItem value="all" selected="True">All</asp:ListItem>
    <asp:ListItem value="ca" selected="False">California</asp:ListItem>
    <asp:ListItem value="co" selected="False">Colorado</asp:ListItem>
    <asp:ListItem value="id" selected="False">Idaho</asp:ListItem>
    <asp:ListItem value="ut" selected="False">Utah</asp:ListItem>
</asp:dropdownlist>

Here is the method:

protected void FilterByState(object sender, EventArgs e)
{
    var value = e;
}

The method will not fire for some reason. I select a different value and nothing happens. What I am trying to do is reload the page passing in the state value so I can filter the results by it.

What am I doing wrong?

score 25 · Accepted Answer · answered Apr 23 '13 at 15:20

25

Set AutoPostBack=True as an attribute of your DDL and it will automatically post back the selected index change event

answered Apr 23 '13 at 15:20

Josh E

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Knew it was something simple. Thank you. – James Wilson Apr 23 '13 at 15:26

score 2 · Answer 2 · answered Apr 23 '13 at 15:21

2

Add this to dropdown list aspx it will cause a request to be send to the server and your event will be fired.

AutoPostBack="true"

answered Apr 23 '13 at 15:21

DotNetUser

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Knew it was something simple. Thank you. – James Wilson Apr 23 '13 at 15:27
No problems, please mark useful answers as an accepted so that others would benefit as well. – DotNetUser Apr 23 '13 at 15:32

score 2 · Answer 3 · answered Apr 23 '13 at 15:22

2

You just need to set AutoPostBack = True

From ListControl.AutoPostBack property;

Gets or sets a value indicating whether a postback to the server automatically occurs when the user changes the list selection.

answered Apr 23 '13 at 15:22

Soner Gönül

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score 1 · Answer 4 · edited Jul 04 '16 at 06:39

1

AutoPostBack="true" and

write page load event

if (!IsPostBack)
{
   DDL_Designation_Bind();   
}

// Because autopostback properties fire load event then our dropdownlist rebind and always selected index 0 so Not Rebinding dropDownlist

edited Jul 04 '16 at 06:39

Manish Jesani

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answered Jul 04 '16 at 05:45

sunil sahu

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ASP.Net DropDownList OnSelectedIndexChange not firing

4 Answers4

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