How to make this DropDownList works inside the GridView?

Question

I have two tables in my database as following:

Suggestions Table: ID, Title, Description, StatusID... etc

SuggestionsStatus Table: ID, Status

I am using GridView to show the Suggestions and in the last column I put a DropDownList that for selecting the status for each Suggestion. Now, when I tried to show the Status in the DropDownList, I got the following error and I don't know why:

An object reference is required for the non-static field, method, or property 'System.Web.UI.WebControls.ListControl.Items.get'

My ASP.NET code:

<asp:GridView ID="GridView1" runat="server" AllowPaging="True" 
                        AllowSorting="True" AutoGenerateColumns="False" DataKeyNames="ID" 
                        width="950px" CssClass="mGrid"
                        AlternatingRowStyle-CssClass="alt" 
                        RowStyle-HorizontalAlign="Center" 
                        DataSourceID="SqlDataSource1" 
                        OnRowDataBound="GridView1_RowDataBound" >
            <AlternatingRowStyle BackColor="White" ForeColor="#284775" />
            <HeaderStyle Font-Bold = "true" ForeColor="Black" Height="20px"/> 
            <Columns>
                <asp:BoundField DataField="ID" HeaderText="ID" InsertVisible="False" 
                    ReadOnly="True" SortExpression="ID" />
                <asp:BoundField DataField="Title" HeaderText="Title" SortExpression="Title" />
                <asp:BoundField DataField="Description" HeaderText="Description" 
                    SortExpression="Description" />
                <asp:BoundField DataField="Name" HeaderText="Name" SortExpression="Name" />
                <asp:BoundField DataField="Username" HeaderText="Username" 
                    SortExpression="Username" />
                <asp:BoundField DataField="DivisionShortcut" HeaderText="Division" 
                    SortExpression="DivisionShortcut" />
                <asp:TemplateField HeaderText="Status">
                    <ItemTemplate>
                        <asp:DropDownList ID="DropDownList" runat="server" DataSourceID="SqlDataSource2"
                                          Font-Bold="True" ForeColor="#006666" AppendDataBoundItems="false" 
                                          DataTextField="Status" DataValueField="ID" AutoPostBack="true" 
                                          OnDataBound="DropDownList_DataBound">
                        </asp:DropDownList>
                    </ItemTemplate>
                </asp:TemplateField>
            </Columns>
        </asp:GridView>
        <asp:SqlDataSource ID="SqlDataSource1" runat="server" 
            ConnectionString="<%$ ConnectionStrings:testConnectionString %>" 
            SelectCommand="SELECT     dbo.SafetySuggestionsLog.ID, dbo.SafetySuggestionsLog.Title, dbo.SafetySuggestionsLog.Description, dbo.employee.Name, dbo.SafetySuggestionsLog.Username, 
                      dbo.Divisions.DivisionShortcut
FROM         dbo.employee INNER JOIN
                      dbo.SafetySuggestionsLog ON dbo.employee.Username = dbo.SafetySuggestionsLog.Username INNER JOIN
                      dbo.Divisions ON dbo.employee.DivisionCode = dbo.Divisions.SapCode"
                      FilterExpression="[DivisionShortcut] like '{0}%'">

                      <FilterParameters>
                        <asp:ControlParameter ControlID="ddlDivision" Name="DivisionShortcut" 
                                                 PropertyName="SelectedValue" Type="String" />
                    </FilterParameters>
        </asp:SqlDataSource>

        <%--For the DropDownList--%>
        <asp:SqlDataSource ID="SqlDataSource2" runat="server"
        ConnectionString="<%$ ConnectionStrings:testConnectionString %>" 
        SelectCommand="SELECT * FROM [SafetySuggestionsStatus]"></asp:SqlDataSource>

My Code-Behind:

protected void Page_Load(object sender, EventArgs e)
    {

    }

    int i = 1;
    protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        if (e.Row.RowType == DataControlRowType.DataRow)
        {
            e.Row.Cells[0].Text = i.ToString();
            i++;
        }

    }

    protected void DropDownList_DataBound(object sender, EventArgs e)
    {

        if (!IsPostBack)
        {
            DropDownList.Items.Insert(0, new ListItem("--Select--", ""));
        }
    }

So how I can fix this problem?

Answer 1

This is all off the top of my head, so the code might not be perfect, but here's what you need to do:

1. In your RowDataBound, cast an instance of the DropDownList from the row.

   DropDownList drp = (DropDownList)e.Row.Cells[7].FindControl("DropDownList");
   

Then call a databinding function like the one below

1. Bind your datalist

   protected void bindDrop(DropDownList drp)
   {
     if (!IsPostBack)
     {
       drp.Items.Insert(0, new ListItem("--Select--", ""));
       drp.DataBind()
     }
    }
   

That should do it

Answer 2

Based on the exception you seem to be getting you may have to cast the sender in your DropDownList_DataBound event to a DropDownList in order to access its Items collection:

protected void DropDownList_DataBound(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        ((DropDownList)sender).Items.Insert(0, new ListItem("--Select--", ""));
    }
}