Solved

C#: Listview column sorter, numerical Decending???

Posted on 2004-09-09
7
1,982 Views
Last Modified: 2008-01-09
  I found a very nice MicroSoft KB Article on ListView Column Sorting thats allows clicking column headers to sort accending or decending much like native Windows Operating system Listviews do.  HOW TO: Sort a ListView Control by a Column in Visual C# .NET   http://support.microsoft.com/?kbid=319401

   However, one of my five listview columns has numbers and does not sort the way I would like. I realize when the listview is first loaded via an SQL table sort query.

Q. How can I enable a ListView to sort the text columns one way and the numreical columns another way???


Upon loading it looks like this:
150
110
100
90
8
5
2
1


After a column click: (Accending)

1
10
110
12
13
153
16
2
23
24
3

After a column click: (Decending)

3
23
24
185
17

0
Comment
Question by:kvnsdr
  • 4
  • 2
7 Comments
 
LVL 10

Accepted Solution

by:
eternal_21 earned 125 total points
ID: 12019660
Put this class in your project:

  public class MyCompare: System.Collections.IComparer
  {
    private System.Collections.CaseInsensitiveComparer ciComparer = new System.Collections.CaseInsensitiveComparer();
    private System.Text.RegularExpressions.Regex regex = new System.Text.RegularExpressions.Regex(@"\d*");

    public int Compare(object x, object y) // Assuming x, y are Strings (from ListView.Text)
    {
      if(regex.Match((string)x).Success&&regex.Match((string)y).Success)
        return Convert.ToInt32(x).CompareTo(Convert.ToInt32(y));
      else
        return ciComparer.Compare(x, y);
    }
  }

And then change the code:

  private CaseInsensitiveComparer ObjectCompare;

to:

  private MyCompare ObjectCompare;


And change:

  ObjectCompare = new CaseInsensitiveComparer();

to:

  ObjectCompare = new MyCompare();
0
 
LVL 1

Author Comment

by:kvnsdr
ID: 12020458
So far so good, except I get the following error on the new class:

 'MyCompare': member names cannot be the same as their enclosing type
0
 
LVL 1

Author Comment

by:kvnsdr
ID: 12020676
Sorry, my mistake..

Another error though: Input string was not in a correct format:

MyCompare (Line 17):
return Convert.ToInt32(x).CompareTo(Convert.ToInt32(y));

ListViewColumnSorter (Line 58):
compareResult = ObjectCompare.Compare(listviewX.SubItems[ColumnToSort].Text,listviewY.SubItems[ColumnToSort].Text);
0
Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

 
LVL 10

Assisted Solution

by:eternal_21
eternal_21 earned 125 total points
ID: 12020846
Sorry, kvnsdr

Change Regex(@"\d*"), to Regex(@"^\d*$")... I made a little mistake there!
0
 
LVL 1

Author Comment

by:kvnsdr
ID: 12029834
Works like a charm, thank you.........  The completed code is below:


Put this class in your project:

  public class MyCompare: System.Collections.IComparer
  {
    private System.Collections.CaseInsensitiveComparer ciComparer = new System.Collections.CaseInsensitiveComparer();
    private System.Text.RegularExpressions.Regex regex = new System.Text.RegularExpressions.Regex(@"^\d*$");    // Regex(@"\d*");

    public int Compare(object x, object y) // Assuming x, y are Strings (from ListView.Text)
    {
      if(regex.Match((string)x).Success&&regex.Match((string)y).Success)
        return Convert.ToInt32(x).CompareTo(Convert.ToInt32(y));
      else
        return ciComparer.Compare(x, y);
    }
  }

And then change the code:

  private CaseInsensitiveComparer ObjectCompare;

to:

  private MyCompare ObjectCompare;


And change:

  ObjectCompare = new CaseInsensitiveComparer();

to:

  ObjectCompare = new MyCompare();
0
 

Expert Comment

by:cjsteynberg
ID: 12378531
How would you use this code in the a project.  I'm trying to sort a listview.
0
 
LVL 1

Author Comment

by:kvnsdr
ID: 12380689
I initially submitted this question regarding an article and code found at Microsoft. Go to the link below to start with, then back here to fill in a few blanks.......

  http://support.microsoft.com/?kbid=319401
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

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

Entity Framework is a powerful tool to help you interact with the DataBase but still doesn't help much when we have a Stored Procedure that returns more than one resultset. The solution takes some of out-of-the-box thinking; read on!
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…
This Micro Tutorial will give you a basic overview how to record your screen with Microsoft Expression Encoder. This program is still free and open for the public to download. This will be demonstrated using Microsoft Expression Encoder 4.
As a trusted technology advisor to your customers you are likely getting the daily question of, ‘should I put this in the cloud?’ As customer demands for cloud services increases, companies will see a shift from traditional buying patterns to new…

896 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

Need Help in Real-Time?

Connect with top rated Experts

19 Experts available now in Live!

Get 1:1 Help Now