DropDownList in ListView selectedValue always the first one - asp.net

Question

I have a ListView with DropDownList inside. I tried both: fill DropDownList on OnItemDataBound and in Page_Load. I also tried checking PostBack, but nothing helps.
When I try to get value, I always get the first one. I understand that it is because lists get refilled, but how to avoid it? If I fill them only when IsPostBack = false, they became empty.
This is my code:
<asp:ListView runat="server" ID="MyListView">
<LayoutTemplate>
<table border="0" cellpadding="2" cellspacing="0">
<tr>
<th><asp:Literal runat="server" Text='<%$ Resources: Resource, LabelWhole %>' /></th>
<th><asp:Literal runat="server" Text='<%$ Resources: Resource, LabelImport %>' /></th>
<th><asp:Literal runat="server" Text='<%$ Resources: Resource, LabelPeriod %>' /></th>
<th><asp:Literal runat="server" Text='<%$ Resources: Resource, LabelDate %>' /></th>
<th><asp:Literal runat="server" Text='<%$ Resources: Resource, LabelUpload %>' /></th>
</tr>
<asp:PlaceHolder ID="itemPlaceholder" runat="server" />
</table>
</LayoutTemplate>
<ItemTemplate>
<tr>
<td><%# DataBinder.Eval(Container.DataItem, "Whole") %></td>
<td><%# DataBinder.Eval(Container.DataItem, "Upload")%></td>
<td><%# DataBinder.Eval(Container.DataItem, "Period")%></td>
<td><asp:DropDownList runat="server" ID="DaysDropDownList"></asp:DropDownList></td>
<td><asp:FileUpload ID="FileUpload" runat="server" /></td>
</tr>
</ItemTemplate>
</asp:ListView>
foreach (var lvItem in MyListView.Items)
{
if (lvItem.ItemType == ListViewItemType.DataItem)
{
DropDownList dr = lvItem.FindControl("DaysDropDownList") as DropDownList;
for (int i = -1; i >= -12; i--)
{
dr.Items.Add(new ListItem(
DateTime.Now.AddMonths(i).ToString("yyyy MM"),
DateTime.Now.AddMonths(i).ToString("yyyy MM")));
}
}
}
Codebehind:
protected void Page_Load(object sender, EventArgs e)
{
this.Application.DataLayer.LoadData(UserID);
this.MyListView.DataSource = this.Application.DataLayer.Data;
this.MyListView.DataBind();
LoadDropDownLists();
}
private void LoadDropDownLists()
{
foreach (var lvItem in MyListView.Items)
{
if (lvItem.ItemType == ListViewItemType.DataItem)
{
DropDownList dr = lvItem.FindControl("DaysDropDownList") as DropDownList;
dr.Items.Clear();
for (int i = -1; i >= -12; i--)
{
dr.Items.Add(new ListItem(
DateTime.Now.AddMonths(i).ToString("yyyy MM"),
DateTime.Now.AddMonths(i).ToString("yyyy MM")));
}
}
}
}
public void SubmitButtonClick(object sender, EventArgs e)
{
foreach (var lvItem in MyListView.Items)
{
if (lvItem.ItemType == ListViewItemType.DataItem)
{
DropDownList dr = lvItem.FindControl("DaysDropDownList") as DropDownList;
FileUpload fl = lvItem.FindControl("FileUpload") as FileUpload;
if (fl.HasFile)
{
string filename = UploadFile(fl, dr.SelectedValue);
this.Application.DataLayer.SaveUploadRecord(UserID, 0, (int)UploadType.Upload, dr.SelectedValue, filename);
}
}
}
}

Answer 1

When you populate your DropdownList with ListItem, you can set the ListItem's Selected property accordingly.

Answer 2

Create a function in which you bind the dropdownlist, Call this function everytime when the page loads(in the page_load event), but before calling it first clear the existing dropdownlist datasource.