ListView sorting

ListView sorting

• Neha Roy

  The IComparer requires a type, see below:

  internal class ListViewItemComparer:IComparer< >

  
  
  

• bryndabella

  hi Galin,
  
  once again thanks very much for your help, and forgive me for my continued questions, but I have another one:
  
  is there anyway of making the image display to the RIGHT of the column text. At the moment I have an UP and DOWN .bmp in an imagelist and when the user clicks the column it appears. But it appears on the LEFT, I want it to be displayed to the RIGHT of the column text.
  
  e.g.
  
  COLUMN 1 ^ COLUMN 2 COLUMN 3 COLUMN 4
  
  or
  
  COLUMN 1 COLUMN 2 ^
  
  
  

• SkiinBlue

  One more question, the IComparer requires a type, what type must you specify
  
  

• Lauski

  You might want to take a look on those sites :

  http://blog.opennetcf.org/ayakhnin/PermaLink.aspx guid=84e397f0-c273-49b5-ae36-4ee695a644d1

  http://www.codeproject.com/cs/miscctrl/lvsortmanager.asp

  Reinout

  
  
  

• John Childress

  Yes thanks.

  Sorry to keep bothering you, but what happens if its a date column

  
  
  

• Olivier Conq

  I do not understand...

  i post you all code needed for Listview sorting that I use

  Post some code so i could help you with modifications

  
  
  

• asics64

  you must have ImageList and to maintain them. do not forget to clear all images on columns before set new one.

  lvEmployees.Columns[e.Column].ImageList = ilImages; lvEmployees.Columns[e.Column].ImageList = "key";

  
  
  

• cristianin_79

  What if the column is storing DateTime values How would you compare DateTime values in your Switch statement
  
  

• Dragan Jankovic

  there is good article on CodeProject that describes how to do it:

  Based on it I implement it in my project as I have internal class for comparing items

  /// <summary> /// Implements the manual sorting of items by columns. /// </summary> internal class ListViewItemComparer : IComparer { private int _col; public int Column { get { return _col; } set { _col = value; } } private SortOrder _order; public SortOrder Sorting { get { return _order; } set { _order = value; } } public ListViewItemComparer() { _col = 0; _order = SortOrder.None; } public ListViewItemComparer(int column, SortOrder order) { _col = column; _order = order; } #region IComparer Members int IComparer.Compare(object x, object y) { int ret = 0; switch (_col) { case 1: int val1 = 0; int val2 = 0; int.TryParse(((ListViewItem)x).SubItems[_col].Text, out val1); int.TryParse(((ListViewItem)y).SubItems[_col].Text, out val2); ret= val1 - val2; break; case 3: return -1; break; default: ret = String.Compare( ((ListViewItem)x).SubItems[_col].Text, ((ListViewItem)y).SubItems[_col].Text); break; } //modify ret depending on sort order ret = _order == SortOrder.Ascending ret : ret * ret; return ret; } #endregion }

  
  In This class I made changes to compare different columns depeding on their types

  and then I attach to Listview.Columnclick event where I have this code

  private void lvEmployees_ColumnClick(object sender, ColumnClickEventArgs e) { // Set the ListViewItemSorter property to a new ListViewItemComparer // object. Setting this property immediately sorts the // ListView using the ListViewItemComparer object. ListViewItemComparer comparer = this.lvEmployees.ListViewItemSorter as ListViewItemComparer; if ((comparer == null) || ((comparer != null) && (comparer.Column != e.Column)) || ((comparer != null) && (comparer.Column == e.Column) && (comparer.Sorting != SortOrder.Ascending))) this.lvEmployees.ListViewItemSorter = new ListViewItemComparer(e.Column, SortOrder.Ascending); else this.lvEmployees.ListViewItemSorter = new ListViewItemComparer(e.Column, SortOrder.Descending); }

  Hope this helps

  
  
  

• Zaka Khan

  Thanks very much, I marked it as the answer, but the site just crashes each time
  
  

• sshetty

  I see

  Use

  System.Collections.IComparer

  instead of

  System.Collections.Generic.IComparer

  
  
  

• Manos Kelaiditis

  lets assume in method IComparer.Compare case 3 is dateTime column. then we have this

  case 3: DateTime val1 = (DateTime)x; DateTime val2 = (DateTime)y; ret = val1.Ticks - val2.Ticks; break;

  
  
  

• -Eric Bouguen-

  Hi Galin,

  Thanks for the help. Is there no way to show the little down arrow and up arrow

  
  
  
• ListView sorting