Sushila Patel's Weblog

Sample Code: Using Dropdownlist in Editable DataGrid

This article demonstrates how to use Dropdownlist in Editable DataGrid 

Html Source

<asp:DataGrid id="DataGrid1" AutoGenerateColumns="False" ItemStyle-CssClass="cdb-AltRow" 
AlternatingItemStyle-CssClass="cdb-AltRow2"
 DataKeyField="ProductID" OnUpdateCommand="DataGrid1_Update" OnEditCommand="DataGrid1_Edit"
 OnCancelCommand="DataGrid1_Cancel" runat="server">
<Columns>
 <asp:TemplateColumn HeaderText="Discontinued">
 <ItemTemplate>
  <asp:Label ID="lblDiscontinued" 
   Text='<%#ShowVal(Convert.ToBoolean( 
DataBinder.Eval(Container.DataItem, "Discontinued").ToString()) )%>' 
   Runat="server" />
 </ItemTemplate>
 
 <EditItemTemplate>
  <asp:Label runat="server" id="lblProductID" Visible="False" 
  Text='<%# 
DataBinder.Eval(Container.DataItem, "ProductId") %>'/>
  <asp:Label ID="lblEditDiscontinued" 
  Text='<%#ShowVal(Convert.ToBoolean( 
DataBinder.Eval(Container.DataItem, "Discontinued").ToString() ))%>' 
  Runat="server" />
  <asp:DropDownList id="ddlDiscontinued" 
  DataSource="<%# BindTheDiscontinued() %>"  
  OnPreRender="SetDropDownIndex" 
  DataTextField="Discontinued" 
  DataValueField="Discontinued" 
  runat="server" />
 </EditItemTemplate>
     
 </asp:TemplateColumn>
 
 <asp:EditCommandColumn 
 EditText="Edit" CancelText="Cancel"  UpdateText="Update"
        ItemStyle-Width="100px"
        HeaderText="Commands" />
</Columns>
</asp:DataGrid>

Code Behind

string strDiscontinued;
GetData obj;
string strSql;
string strConn;
DataSet ds;
SqlDataReader dr;
private void Page_Load(object sender, System.EventArgs e)
{
 // Put user code to initialize the page here
 strConn ="server=localhost;uid=sa;pwd=;database=northwind";
 if (!Page.IsPostBack )
 {
    BindGrid();
 }
}

//*******
//To Bind the DataGrid
//******* 
void BindGrid()
{
    obj=new GetData ();
    strSql = "Select productid, discontinued from Products";
    ds=obj.GetDataFromTable (strSql ,strConn);
    DataGrid1.DataSource =ds;
    DataGrid1.DataBind (); 
}

//*******
//To display Yes/No for True/False
//*******
protected string ShowVal(bool blnval)
{
    if (blnval==true)
    {
      return "Yes";
    } 
    else
    {
      return "No";
    }
}

//*******
//Bind the Data to the dropdownlist in the EditTemplate
//*******
protected SqlDataReader BindTheDiscontinued()
{
    obj=new GetData ();
    strSql ="SELECT distinct 'Discontinued' =" ;
    strSql+=" CASE ";
    strSql+=" WHEN Discontinued = 1 Then 'Yes'" ;
    strSql+=" ELSE 'No'" ;
    strSql+=" END " ;
    strSql+=" From Products ";
    dr=obj.GetSingleDataUsingReader (strSql ,strConn);
    return dr;
}

//*******
//Set the Text of the Dropdownlist to the field value in Database
//*******
protected void SetDropDownIndex(Object sender ,System.EventArgs e   )
{
    DropDownList ed ; 
    ed = (DropDownList) sender;
    ed.SelectedIndex = ed.Items.IndexOf(ed.Items.FindByText(strDiscontinued));
}

//*******
//For Edit Update Cancel
//*******
public void DataGrid1_Edit(Object sender, DataGridCommandEventArgs e)
{
    strDiscontinued = ((Label )e.Item.FindControl("lblDiscontinued")).Text;
    DataGrid1.EditItemIndex = (int)e.Item.ItemIndex;    
    BindGrid(); 
}

public void DataGrid1_Update(Object sender, DataGridCommandEventArgs e)
{
    DropDownList TempList ; 
    String TempValue ; 
    TempList = (DropDownList) e.Item.FindControl("ddlDiscontinued");
    TempValue = TempList.SelectedItem.Value;
    //Place update code here
    Response.Write (TempValue);
    DataGrid1.EditItemIndex = -1;
    BindGrid();
}
public void DataGrid1_Cancel(Object sender, DataGridCommandEventArgs e)
{
   DataGrid1.EditItemIndex = -1;
   BindGrid();
}

//
//*******
//Functions used in Class GetData.cs
//*******
SqlConnection mycn;
SqlDataAdapter myda;
SqlCommand mycmd;
DataSet ds;
String strConn;
SqlDataReader myReader;
public DataSet GetDataFromTable(string strSQL ,string strConnString)
{
 try
 {
    strConn=strConnString;
    mycn = new SqlConnection(strConn);
    myda = new SqlDataAdapter (strSQL, mycn);
    ds= new DataSet ();
    myda.Fill (ds,"Table");
    return ds;
 }
 catch(Exception ex)
 {
    throw new Exception (ex.Message.ToString ());
 }
 finally
 {
    mycn.Close ();
 }
}
public SqlDataReader GetSingleDataUsingReader(string strSQL ,string strConnString)
{
 try
 {
    strConn=strConnString;
    mycn = new SqlConnection(strConn);
    mycmd = new SqlCommand  (strSQL, mycn);
    mycn.Open ();
    myReader=mycmd.ExecuteReader(CommandBehavior.CloseConnection ); 
    return myReader;
 }
 catch(Exception ex)
 {
    throw new Exception (ex.Message.ToString ());
 }
 finally
 {
    //mycn.Close ();
 }
}