AlbreK01

I am writing a C# Windows app that will contain more than one ListView control. Because one form will contain more than one ListView control, I want to try to use the Singleton pattern on the implementation of my "iComparer" interface class.

The code compiles nicely, but at run time, I get the error of "Object Is Not Set To Instance Of An Object".

Is there anything different I need to be doing to assign the singleton instance of my "iComparer" class to the ListViewItemSorter?

Or, Is there some reason why I cannot make this a singleton and if so, how else can I define the "iComparer" class so that there is only one instance alive throughout the life of the application.

I am attaching code files for reference, but here is some code snippets, too .......

From "Form1.CS"

ListViewColumnSorter.GetInstance() ;
this.listBox1.ListViewItemSorter = (IComparer)(ListViewColumnSorter.GetInstance()) ;

From "ListViewColumnSorter.cs"

public sealed class ListViewColumnSorter : IComparer
{
/// <summary>
/// ALBREK01 :: Define static singleton instance of class
/// </summary>
private static readonly ListViewColumnSorter instance = new ListViewColumnSorter() ;

// Explicit static constructor to tell C# compiler
// not to mark type as beforefieldinit
// ALBREK01 :: Class constructor
static ListViewColumnSorter()
{
InitColumnSorter () ;
}

// ALBREK01 :: Public access to singleton class instance
public static ListViewColumnSorter GetInstance()
{
return (instance) ;
}
}


Please help ....... I'm desperate.

Attached Files

	Form1.txt (8.3 KB, 0 views)
	ListViewColumnSorter.txt (6.8 KB, 0 views)