how to bind a dropdownlist in gridview?

Question

I have a gridview in which every row contains a dropdownlist. I want to bind every dropdownlist dynamically. Can someone tell me how can i do it. Thanks in Advance

VinayC · Accepted Answer · 2011-09-07T05:40:56.980

If you are using template column then you can bind your drop-down from mark-up using data-binding expressions. For example,

<asp:TemplateField HeaderText="XYZ">
  <ItemTemplate>
    <asp:DropDownList runat="server" ID="MyDD" DataSourceId="MyDataSource" />
  </ItemTemplate> 
</asp:TemplateField>

Above is assuming that your drop-down data in constant across rows. If it is changing then you can use data-binding expression such as

<asp:DropDownList runat="server" DataSource='<%# GetDropDownData(Container) %>' DataTextField="Text" DataValueField="Value"  />

GetDropDownData will be a protected method in code-behind that will return the data (data-table, list, array) for the given row.

You can use GridView.RowDataBound event (or RowCreated event) in code-behind to fill drop-downs. For example,

  protected void GridView_RowDataBound(Object sender, GridViewRowEventArgs e)
  {

    if(e.Row.RowType == DataControlRowType.DataRow)
    {
      // Find the drop-down (say in 3rd column)
      var dd = e.Row.Cells[2].Controls[0] as DropDownList;
      if (null != dd) {
         // bind it
      }

      /*
      // In case of template fields, use FindControl
      dd = e.Row.Cells[2].FindControl("MyDD") as DropDownList;
      */
    }

  }

What about the RowCreated event? Would there be a reason to prefer one over the other? — Tim, Sep 07 '11 at 05:31
@Tim, RowCreated will also work. However, I believe that if you are binding the grid only first time (and not on post-back), `RowCreated` will certainly fire on every post-back but not `RowDataBound` (I am not 100% sure here). So in such case, we can rely on view-state to get drop-down to filled up. Personally, I prefer markup route. — VinayC, Sep 07 '11 at 05:47
This is assumed that you have your SQL instance declared in your code. If you already bound your grid view in your code behind then there needs to be a different solution, because you would not be able to use DataSourceId="MyDataSource" — Coded Container, Sep 19 '17 at 15:46

score 16 · Answer 2 · answered Sep 07 '11 at 05:34

In addition to the proposed methods, you may also bind your controls within your markup, in this way:

<asp:GridView ID="MyGrid" runat="server" DataSourceID="MyDataSource1">
    <Columns>
        <asp:TemplateField>
            <EditItemTemplate>
                <asp:DropDownList ID="DropDownList1" runat="server" SelectedValue='<%# Bind ("CustomerId") %>' DataSourceID="CustomersDataSource" DataTextField="CustomerName" DataValueField="CustomerId" >
                </asp:DropDownList>
            </EditItemTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>

Can you show how this would update and display in the label of the ItemTemplate? — htm11h, Nov 17 '14 at 19:42

Chandan Kumar · Answer 3 · 2014-01-21T01:14:23.580

Here is your gridview

<asp:GridView ID="grvExcelData" runat="server" onrowdatabound="GridView2_RowDataBound">
    <HeaderStyle BackColor="#df5015" Font-Bold="true" ForeColor="White" />
      <Columns>
          <asp:TemplateField>
              <ItemTemplate>
                 <asp:DropDownList ID="DrdDatabase" Width="100px" runat="server">
                 </asp:DropDownList>
              </ItemTemplate>
          </asp:TemplateField>
      </Columns>
  </asp:GridView>

and your RowDataBound event for the gridview would be

    protected void GridView2_RowDataBound(object sender, GridViewRowEventArgs e)
    {
       string cities = "maxico,chennai,newdelhi,hongkong";
       string [] arr = cities.Split(',');
    // Instead of string array it could be your data retrieved from database.
        if (e.Row.RowType == DataControlRowType.DataRow)
        {
            DropDownList ddl = (DropDownList)e.Row.FindControl("DrdDatabase");
            foreach (string colName in arr )
                ddl.Items.Add(new ListItem(colName));
        }
    }

This does not look like this is bound to a database but instead attached to an array of cities. If a user makes a change to the drop-down how will this update the database? — Coded Container, Sep 19 '17 at 15:44

score -1 · Answer 4 · edited Aug 29 '13 at 09:13

protected void gvSalesAppData_RowDataBound(Object sender, GridViewRowEventArgs e)

    {

        if (e.Row.RowType == DataControlRowType.DataRow)
        {

            DropDownList ddlCurrentPhase = (DropDownList)e.Row.FindControl("ddlCurrentPhase");
            DropDownList ddlProductFamily = (DropDownList)e.Row.FindControl("ddlProductFamily");
            DropDownList ddlProductGroup = (DropDownList)e.Row.FindControl("ddlProductGroup");
            DropDownList ddlETProgramManager = (DropDownList)e.Row.FindControl("ddlETProgramManager");
            DropDownList ddlPLMForTheProduct = (DropDownList)e.Row.FindControl("ddlPLMForTheProduct");

            TrackingToolObj.BindCurrentPhases(ddlCurrentPhase);
            TrackingToolObj.BindCurrentPhases(ddlProductFamily);
            TrackingToolObj.BindProductGroups(ddlProductGroup);
            TrackingToolObj.GetEmployeesBasedOnRoleTypeId(ddlETProgramManager, (int)OSAEnums.RoleTypes.ProgramManager, false);
            TrackingToolObj.GetEmployeesBasedOnRoleTypeId(ddlPLMForTheProduct, (int)OSAEnums.RoleTypes.PLM, false);


        }

    }

score -2 · Answer 5 · edited Jul 25 '14 at 12:48

Binding the GridView

Below is the code to Bind the GridView control with data.

C#

protected void Page_Load(object sender, EventArgs e)
{
   if (!IsPostBack) 
   {
     this.BindData();   
   }
} 

private void BindData()
{
   string query = "SELECT top 10 * FROM Customers";    
   SqlCommand cmd = new SqlCommand(query);    
   gvCustomers.DataSource = GetData(cmd);    
   gvCustomers.DataBind(); 
}

private DataTable GetData(SqlCommand cmd)
{    
    string strConnString = ConfigurationManager.ConnectionStrings["conString"].ConnectionString;    
    using (SqlConnection con = new SqlConnection(strConnString))   
    {        
       using (SqlDataAdapter sda = new SqlDataAdapter())     
       {            
          cmd.Connection = con;            
          sda.SelectCommand = cmd;            
          using (DataTable dt = new DataTable())  
          {                
              sda.Fill(dt);                
              return dt;
          }     
       }   
    }
}

please edit your answer and format the code to make it readable — kleopatra, Oct 14 '13 at 09:24
To be honest, that's a daft way of doing it. If you have 500 rows in a gridview, you are going to query a database 500 times? When I have to do this, I fill a dataset with the data for the items in the drop down list and, as shown above, in the RowDataBound event, bind the DataSet to the dropdownlist(s). — Martin Smellworse, Oct 14 '13 at 09:50

how to bind a dropdownlist in gridview?

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