下拉列表不添加项目

Question

I am working on implementing a DropDownList for a website (not my own website) and I can not get the DropDownList to populate any items. Bit frustrating but that's the life of a coder right? This is what I have for the code so far regarding the DropDownList . I have an understanding of C# but aspx and the bridge between them is new to me so I might of missed something obvious. Could someone steer me in the right direction?

aspx file's DropDown Generation

<asp:DropDownList runat="server" ID="dpdCategory" Width="200px"/>

Init to ID in .cs file

protected DropDownList dpdCategory;

Function to Generate the Items

protected void Page_Load(object sender, EventArgs e)
{
    this.dpdCategory.Items.Clear();
    this.dpdCategory.Items.Add(new ListItem("hello", "0"));
    this.dpdCategory.Items.Add(new ListItem("hello", "1"));
}

Answer 1

You might need to put it when the page is not posting back. Like this:

protected void Page_Load(object sender, EventArgs e)
{
    if(!Page.IsPostBack)
    {
        this.dpdCategory.Items.Clear();
        this.dpdCategory.Items.Add(new ListItem("hello", "0"));
        this.dpdCategory.Items.Add(new ListItem("hello", "1"));
    }
}

Answer 2

  var categories = new List<ListItem>
                {
                    new ListItem("hello", "0"),
                    new ListItem("hello", "1")
                };

dpdCategory.DataTextField = "Text";
dpdCategory.DataValueField = "Value";
dpdCategory.DataSource = categories ;
dpdCategory.DataBind();

Answer 3

You dont have to initialise dropdownlist in .cs file.

Then change your page load like this:

 protected void Page_Load(object sender, EventArgs e)
    {
        dpdCategory.Items.Clear();
        dpdCategory.Items.Add(new ListItem("hello", "0"));
        dpdCategory.Items.Add(new ListItem("hello", "1"));
    }

This should work.