WinForms ListBox with readonly/disabled items

Question

Is there a way to make some of the items in a ListBox readonly/disabled so they can\'t be selected? Or are there any similar controls to ListBox to provide this functionalit

Answer 1

ListBox doesn't have a ReadOnly (or similar) property, but you can make a custom ListBox control. Here's a solution that worked pretty well for me:

https://ajeethtechnotes.blogspot.com/2009/02/readonly-listbox.html

public class ReadOnlyListBox : ListBox 
{ 
    private bool _readOnly = false; 
    public bool ReadOnly 
    { 
        get { return _readOnly; } 
        set { _readOnly = value; } 
    } 

    protected override void DefWndProc(ref Message m) 
    { 
        // If ReadOnly is set to true, then block any messages 
        // to the selection area from the mouse or keyboard. 
        // Let all other messages pass through to the 
        // Windows default implementation of DefWndProc.
        if (!_readOnly || ((m.Msg <= 0x0200 || m.Msg >= 0x020E) 
            && (m.Msg <= 0x0100 || m.Msg >= 0x0109) 
            && m.Msg != 0x2111 
            && m.Msg != 0x87)) 
        {
            base.DefWndProc(ref m); 
        } 
    } 
}