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Databind ListView not Updating after Postback

Posted on 2009-03-30
10
1,250 Views
Last Modified: 2013-12-17
Hi All,

This is probably really simple, but I just cannot see what I am doing wrong - or not doing!

I have a list of files (FileInfo array databound to a ListView) and it displays fine, all it does is list the file names and links them. - Simple.

The problem is that when I upload a new file and the page performs it's post-back, the ListView does not update. But if I go to the page with the ListView by browsing to it again, the list has updated.

I have seen this issue before, but I was able to 'fix' it by forcing a Response.Redirect to itself. - I don't like this at all!

I also tried to perform a Databind immediately after uploading (see the code below) but the issue still exists - no update after postback.

Any help on this would be appreciated.

Cheers,
James


protected void btnUpload_Click(object sender, EventArgs e)
{
  if (fileUpload.HasFile)
  {
    fileUpload.SaveAs(dirServerPath + @"\" + fileUpload.FileName);
    fileList.DataBind();
  }
}

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Comment
Question by:JR-Patterson
  • 5
  • 5
10 Comments
 
LVL 16

Expert Comment

by:burakiewicz
ID: 24020700
do you have any update panels on the page?
0
 

Author Comment

by:JR-Patterson
ID: 24020730
Nope. It's all pretty standard stuff.
0
 
LVL 16

Expert Comment

by:burakiewicz
ID: 24020762
when does the new file get added to the array of FileInfo?
0
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Author Comment

by:JR-Patterson
ID: 24020807
Well the directory should be looked up every time the page loads, so the array should update. Here is pretty much what is going on in the page load.

Cheers
if (!dir.Exists)
{
  Directory.CreateDirectory(Server.MapPath(docsDir + "/" + currentCompanyID.ToString()));
}
else
{
  files = dir.GetFiles();
  fileList.DataSource = files;
  fileList.DataBind();
}

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Assisted Solution

by:burakiewicz
burakiewicz earned 300 total points
ID: 24020846
i dont think the way its setup it picks up the new file try this.  
protected void btnUpload_Click(object sender, EventArgs e)
{
  if (fileUpload.HasFile)
  {
    fileUpload.SaveAs(dirServerPath + @"\" + fileUpload.FileName);
    files = dir.GetFiles();
    fileList.DataBind();
  }
}

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0
 

Author Comment

by:JR-Patterson
ID: 24020874
Still no luck I'm afraid. Same result. :(
0
 

Accepted Solution

by:
JR-Patterson earned 0 total points
ID: 24020916
This works though!

Should it really be like this? I guess it could just be made into an 'update' method so I don't have to write it over and over... seems silly though.

Thanks a lot for your help.
protected void btnUpload_Click(object sender, EventArgs e)
{
  if (fileUpload.HasFile)
  {
    fileUpload.SaveAs(dirServerPath + @"\" + fileUpload.FileName);
 
    files = dir.GetFiles();
    fileList.DataSource = files;
    fileList.DataBind();
  }
}

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0
 
LVL 16

Assisted Solution

by:burakiewicz
burakiewicz earned 300 total points
ID: 24020924
ok just as a test try something like this ull need to put in the code where it gets the dir

protected void btnUpload_Click(object sender, EventArgs e)
{
  if (fileUpload.HasFile)
  {
 
    fileUpload.SaveAs(dirServerPath + @"\" + fileUpload.FileName);
    
if (!dir.Exists)
{
  Directory.CreateDirectory(Server.MapPath(docsDir + "/" + currentCompanyID.ToString()));
}
else
{
  files = dir.GetFiles();
  fileList.DataSource = files;
  fileList.DataBind();
}
 
  }
}

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0
 
LVL 16

Expert Comment

by:burakiewicz
ID: 24020943
it has to be that way.  Because this event
protected void btnUpload_Click(object sender, EventArgs e)
is fired after the page load. so that is why it was never showing up  You should put it in an update method so you only have to code it in 1 place
0
 

Author Comment

by:JR-Patterson
ID: 24020973
Makes sense. I will keep this in mind.

Thanks a lot for your help - greatly appreciated.
0

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