动态控件ASP.NET

Question

In web page, created controls dynamically and when select dropdown item ddl do not remember selected item

example

protected void Page_Init(object sender, EventArgs e)
{

    // create

    DropDownList ddl = new DropDownList();
    ddl.SelectedIndexChanged += new EventHandler(ddl_selectedIndexChanged);
    ddl.AutoPostBack = true;

    //....

    Page.Controls.Add(ddl);

    // Fill dropdownlist when page loaded first time

    ddl.DataSource = LoadFormDataBase;
    ddl.DataBind();
}

protected void ddl_selectedIndexChanged(object sender, EventArgs e)
{
    //
}

When selected dropdown item web page recreated and my selected item disappear, ViewState do not work. This dynamic controls often used and I have an doubt to use Session?

Answer 1

Follow the below way:

http://www.codeproject.com/Articles/502251/How-to-create-controls-dynamically-in-ASP-NET-and

You need to handle viewstate carefully.