DropDownList 事件不会触发

Question

I'm having trouble with my DropDownList. The events don't fire! I've tested it on a separate project, with a DropDownList and a literal. Every time the selected value would change, I would add a little star “*” to the literal. No problems what so ever. But every time I try it on my webpage in the project, it fails.

Here is an image.

protected void ddlConsole_SelectedIndexChanged(object sender, EventArgs e)
{
    ltlTesting.Text += "*";
}

UPDATE:

I've tried some things but still with no succes. I hope someone can tell me what i'm doing wrong. I'm wiring the events in the code behind now, but i've added a linkbutton next to the dropdownlist to see if it works.

protected override void OnInit(EventArgs e)
    {
        base.OnInit(e);
        ddlConsole.SelectedIndexChanged += new EventHandler(ddlConsole_SelectedIndexChanged);
        lnkGet.Click += new EventHandler(ddlConsole_SelectedIndexChanged);
    }

Here is an image to see what's going on. The stripe in the literal at the beginning is added in pageload with the same code the star is added. Just to be sure it doesn't load twice. The "GET" linkbutton works fine. The dropdownlist doesn't...

Answer 1

Have you Set

AutoPostBack="true"

in control properties??

EDIT:

Remove

OnSelectedIndexChanged="ddlConsole_SelectedIndexChanged"

from the markup in the ASPX page and try again only with AutoPostback true and the event defined in codebehind. The aspx page should look like this:

 <asp:DropDownList runat="server" ID="ddlConsole" AutoPostBack="True"></asp:DropDownList>

Answer 2

下拉列表的AutoPostBack是true吗？

Answer 3

检查 Dropdownlist 的 AutopostBack 属性将其设置为 true ：

Answer 4

如果图片正确并且AutoPostBack="True" ，是否有任何代码在页面加载时设置ltlTesting的值？

Answer 5

Add the AutoPostback="True" and OnSelectedIndexChanged="ddlConsole_SelectedIndexChanged" to the ddlConsole attributes. You can delete the OnInit method, since you bound the SeletedIndexChanged event at design time.