Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people, just like you, are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
Solved

Databind ListView not Updating after Postback

Posted on 2009-03-30
10
1,246 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();
  }
}

Open in new window

0
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
Space-Age Communications Transitions to DevOps

ViaSat, a global provider of satellite and wireless communications, securely connects businesses, governments, and organizations to the Internet. Learn how ViaSat’s Network Solutions Engineer, drove the transition from a traditional network support to a DevOps-centric model.

 

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();
}

Open in new window

0
 
LVL 16

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();
  }
}

Open in new window

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();
  }
}

Open in new window

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();
}
 
  }
}

Open in new window

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

Featured Post

MIM Survival Guide for Service Desk Managers

Major incidents can send mastered service desk processes into disorder. Systems and tools produce the data needed to resolve these incidents, but your challenge is getting that information to the right people fast. Check out the Survival Guide and begin bringing order to chaos.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

International Data Corporation (IDC) prognosticates that before the current the year gets over disbursing on IT framework products to be sent in cloud environs will be $37.1B.
Real-time is more about the business, not the technology. In day-to-day life, to make real-time decisions like buying or investing, business needs the latest information(e.g. Gold Rate/Stock Rate). Unlike traditional days, you need not wait for a fe…
With Secure Portal Encryption, the recipient is sent a link to their email address directing them to the email laundry delivery page. From there, the recipient will be required to enter a user name and password to enter the page. Once the recipient …

840 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question