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c# - DropdownList.selectedIndex always 0 (yes, I do have !isPostBack)

(Scroll down to bottom of post to find solution.)

Got a asp.net page which contains a Datalist. Inside this datalist, there is a template containing a dropdownlist and each time the datalist is filled with an item, a ItemCreatedCommand is called. The itemCreatedCommand is responsible for databinding the dropdownlist.

I think the problem lies here, that I'm using ItemCreatedCommand to populate it - but the strange things is that if I choose the color "green", the page will autopostback, and I will see that the dropdown is still on the color green, but when trying to use it's SelectedIndex, I always get 0...

protected void DataListProducts_ItemCreatedCommand(object
    source, DataListItemEventArgs e)

 var itemId = (String)DataListProducts.DataKeys[e.Item.ItemIndex];
 var item = itemBLL.GetFullItem(itemId); 

 var DropDownListColor = (DropDownList)e.Item.FindControl("DropDownListColor");

 //Also tried with :
 //if(!isPostBack) {

 DropDownListColor.DataSource = item.ColorList;
 DropDownList.Color.Databind();

 // } End !isPostBack)

    Label1.test = DropDownListColor.SelectedIndex.toString();
 // <- THIS IS ALWAYS 0! *grr* 

I've narrowed down the code a bit for viewing, but still you can see what I'm trying to do :) The reason for why I'm doing this, and not declaring the datasource for the colors directly i aspx-page, is that I need to run a test if(showColors), but I do not want to clutter up the html-page with code that I feel should be in the code behind-file.

EDIT: After trying to alter SelectedIndexChange - I'm having a "logical" confusion in my head now - how am I to alter elements inside the datalist? Since, as far as I know - I do not have any way to check which of the items in the datalist this particular dropdownlist belongs to... Or? I'm going to try out a few ways and see what I end up with ;) But do please post your thoughts on this question :)

SOLUTION:

Either bubble the event to ItemCommand, or Handle the event, get the senders parent(which is a datalistItem and manipulate elements in there.

 protected void DropDownListColor_SelectedIndexChanged(object sender, EventArgs e)
        {
            DropDownList dropDownListColor = (DropDownList)sender;
            DataListItem dataListItem = (DataListItem)dropDownListColor.Parent;

            var item = items[dataListItem.ItemIndex];
            var color = item.ItemColor[dropDownListColor.SelectedIndex];

            var LabelPrice = (Label)dataListItem.FindControl("LabelPrice");
            LabelPrice.Text = color.Price; 
        }
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1 Answer

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When the DataList is data-bound, the AutoPostBack has not been handled yet, i.e. the values in the ItemCreated event are still the original values.

You need to handle the SelectedIndexChange event of the dropdown control.


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