Hello, 

I have a DataList control that is bound to a DataSet that contains 3 
fields. In the EditItemTemplate, the first and second fields are displayed 
in standard text boxes. The problem is with the third field. Depending on 
the value in this field, I may need to use a RadioButtonList or a TextBox. 

I figured I'd just put a PlaceHolder control in the EditItemTemplate, and 
then in the EditCommand event handler I'd dynamically add the appropriate 
control. As a test, I just tried to add a TextBox control. I'm using the 
following code: 

public void lstQuestions_EditCommand(object source, 
DataListCommandEventArgs e) 
{ 
lstQuestions.EditItemIndex = e.Item.ItemIndex; 
lstQuestions.SelectedIndex = e.Item.ItemIndex; 
PlaceHolder plhOptions = (PlaceHolder)lstQuestions.FindControl
("plhOptions"); 
TextBox t = new TextBox(); 
plhOptions.Controls.Add(t); 
bindData(); 
} 

The line where I add the TextBox to the PlaceHolder raises the following 
error: Exception Details: System.NullReferenceException: Object reference 
not set to an instance of an object. 

Am I adding this code to the wrong section, or is it some sort of syntax 
error? Thanks for any help you can provide! 

Brian 

Use (PlaceHolder)lstQuestions.item(e.Item.ItemIndex).FindControl
("plhOptions"); 

--Regards
Jaya

> Hello, 

> I have a DataList control that is bound to a DataSet that contains 3 
f> ields. In the EditItemTemplate, the first and second fields are 
displayed 
i> n standard text boxes. The problem is with the third field. Depending 
on 
t> he value in this field, I may need to use a RadioButtonList or a 
TextBox. 

> I figured I'd just put a PlaceHolder control in the EditItemTemplate, 
and 
t> hen in the EditCommand event handler I'd dynamically add the 
appropriate 
c> ontrol. As a test, I just tried to add a TextBox control. I'm using 
the 
f> ollowing code: 

> public void lstQuestions_EditCommand(object source, 
D> ataListCommandEventArgs e) 
{>  
l> stQuestions.EditItemIndex = e.Item.ItemIndex; 
l> stQuestions.SelectedIndex = e.Item.ItemIndex; 
P> laceHolder plhOptions = (PlaceHolder)lstQuestions.FindControl
(> "plhOptions"); 
T> extBox t = new TextBox(); 
p> lhOptions.Controls.Add(t); 
b> indData(); 
}>  

> The line where I add the TextBox to the PlaceHolder raises the 
following 
e> rror: Exception Details: System.NullReferenceException: Object 
reference 
n> ot set to an instance of an object. 

> Am I adding this code to the wrong section, or is it some sort of 
syntax 
e> rror? Thanks for any help you can provide! 

> Brian