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| Ray Houston |
(If there is a better list to post this problem, please let me know.) I'm
building a control that contains a DataGrid control which has a Template
column which contains a DropDownList. The DropDownList renders fine with
it's DataSource, but I would like to add a blank row to the items and select
a default item.
He is a stripped down code of my control:
protected override void OnInit(EventArgs E)
{
myTemplateColumn = new TemplateColumn();
myTemplateColumn.HeaderText = "Role";
myTemplateColumn.ItemTemplate = new RoleColumn();
SourceDataGrid.Columns.Add(myTemplateColumn);
base.OnInit(E);
}
protected override void CreateChildControls()
{
SourceDataGrid.SortCommand += new
DataGridSortCommandEventHandler(this.Sort);
SourceDataGrid.ItemDataBound += new
DataGridItemEventHandler(this.ItemDataBound);
this.Controls.Add(SourceDataGrid);
}
Here is my ITemplate class that builds the DropDown in the DataGrid:
public class RoleColumn : ITemplate
{
public void InstantiateIn(Control container)
{
DropDownList myDropDownList = new DropDownList();
myDropDownList.ID = "RoleID";
myDropDownList.DataSource = BaseDB.GetList(0,"Role");
myDropDownList.DataTextField = "Text";
myDropDownList.DataValueField = "Value";
myDropDownList.CssClass = "formTB";
myDropDownList.DataBinding += new EventHandler(this.BindRoleColumn);
container.Controls.Add(new LiteralControl("<center>"));
container.Controls.Add(myDropDownList);
container.Controls.Add(new LiteralControl("</center>"));
}
public void BindRoleColumn(object sender, EventArgs e)
{
int SelectedRoleID;
DropDownList dropdownlist = (DropDownList)sender;
dropdownlist.Items.Insert(0, " ");
dropdownlist.Items[0].Value = "0";
DataGridItem container = (DataGridItem)dropdownlist.NamingContainer;
SelectedRoleID =
Convert.ToInt32(((DataRowView)container.DataItem)["RoleID"]);
if (dropdownlist.Items.FindByValue(SelectedRoleID.ToString()) != null)
dropdownlist.Items.FindByValue(SelectedRoleID.ToString()).Selected =
true;
}
}
It doesn't even add the new Item to the DropDownList. I had though that my
'BindRoleColumn' wasing even being executed, but I force an exception there
and it throws it. Thanks for the help.
-Ray
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| Andrea Williams |
I'm having the same issue, however I've discovered that the Item is being added, but not showing up in the list. The reason I think it's added is that if my DataSet value that is to be bound with the control is equal to "", then I don't get an error. Howver, if I take out the line:
cboSender.Items.Insert(0, new ListItem("[Select One]", ""));
then the page errors b/c there's not a value with which to match an item in the DropDownList.
I don't see a date on this post so I'm not sure when it was posted, but I really need this to work!
My ITemplate code is as follows:
/// <summary> Instantiation of the Item Template</summary>
public override void InstantiateIn(Control container)
{
// Bind a string to the event
DropDownList cboResult = new DropDownList();
if (this.ControlID != null)
cboResult.ID = this.ControlID;
cboResult.DataSource = this.mobjDataSource;
cboResult.DataTextField = this.mstrDataTextField;
cboResult.DataValueField = this.mstrDataValueField;
cboResult.DataBinding += new EventHandler(this.BindData);
container.Controls.Add(cboResult);
}
/// <summary> Binds the DataField to the specified Label</summary>
protected void BindData(object sender, System.EventArgs e)
{
if (!Common.Global.isNothing(this.DataField))
{
DropDownList cboSender = (DropDownList) sender;
DataGridItem container = (DataGridItem) cboSender.NamingContainer;
string strDataFieldValue = ((System.Data.DataRowView)container.DataItem)[this.DataField].ToString();
cboSender.Items.Insert(0, new ListItem("[Select One]", ""));//This is the line that isn't working
// BTW, if I leave this line out and the value of strDataFieldValue = "", I get an error b/c the value "" doesn't exist in the DataSet.
cboSender.SelectedValue = strDataFieldValue;
cboSender = null;
}
}
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From: Andrea Williams
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