FindControl in DataList Edit Mode
- by Doug
As a new .net/C# web begginner, I always get tripped up when I try to use FindControl. Blam -flat on my face. Here is my current FindControl problem:
I have an .aspx page and Form, then ajax updatePanel, inside it there is my DataList (DataList1) that has an EditItemTemplate: that has the following:
<EditItemTemplate>
<asp:Label ID="thumbnailUploadLabel" runat="server" text="Upload a new thumbnail image:"/><br />
<asp:FileUpload ID="thumbnailImageUpload" runat="server" />
<asp:Button ID="thunbnailImageUploadButton" runat="server" Text="Upload Now" OnClick="thumbnailUpload"/><br />
</EditItemTemplate>
In my C# code behind I have the OnClick code for the fileUpload object:
protected void thumbnailUpload(object s, EventArgs e)
{
if (thumbnailImageUpload.HasFile)
{
//get name of the file & upload
string imageName = thumbnailImageUpload.FileName;
thumbnailImageUpload.SaveAs(MapPath("../../images/merch_sm/" + imageName));
//let'em know that it worked (or didn't)
thumbnailUploadLabel.Text = "Image " + imageName + "has been uploaded.";
}
else
{
thumbnailUploadLabel.Text = "Please choose a thumbnail image to upload.";
}
So of course I'm getting "Object reference not set to an instance of an object" for the FileUpload and the Label.
What is the correct syntax to find these controls, before dealing with them in the OnClick event?
The only way Ive used FindControl is something like:
label thumbnailUploadLabel = DataList1.FindControl("thumbnailUploadLabel") as Label;
But of course this is throwing the "Object reference not set to an instance of an object" error. Any help is very much appreciated.
(I've also seen the 'recursive' code out there that is supposed to make using FindControl easier. Ha! I'm so green at C# that I don't even know how to incorporate those into my project.)
Thanks to all for taking a look at this.
