CODEWITHSUNDEEP
c#winformsevents
Emil Condrea
Emil Condrea

Reputation: 9963

C# global event accesed from multiple forms

I have a function that deselect all selected items in the listbox when the user right clicks on listbox. Is there a way to apply this function to all listboxes in my project?

I want to know if there's another way , not making a class and put the function in the class etc:

public class selectedListbox{
   private void setSelected(ListBox details){
   details.MouseDown += new System.Windows.Forms.MouseEventHandler(this.listBoxDeselectAll);
   }

   private void listBoxDeselectAll(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Right)
            {
                ((ListBox)sender).ClearSelected();
            }
        }

}

and then for each listbox to do this:

selectedListBox h = new selectedListBox();
h.setSelected(listboxNameHere);

Upvotes: 1

Views: 1356

Answers (3)

shelleybutterfly
shelleybutterfly

Reputation: 3247

maybe with an extension + lambda?

public static class ListBoxSelectExtension
{
  public static void SetSelected(this ListBox Me)
  {
      Me.MouseDown +=
          (sender, e) =>
          {
              if (e.Button == MouseButtons.Right)
                  ((ListBox)sender).ClearSelected();
          };
  }
}

this way you can do the following without having to instantiate a new class or having to have all your listboxes be a derived class:

MyListBox1.SetSelected();
MyListBox2.SetSelected();

etc.

Upvotes: 2

CharithJ
CharithJ

Reputation: 47490

   public class MyListBox : ListBox
    {
        public sListBox() : base()
        {
             MouseDown += new System.Windows.Forms.MouseEventHandler( this.MouseDownFired ); 
        }

        private void MouseDownFired(object sender, MouseEventArgs args)
        {
          if ( args.Button == MouseButtons.Right ) 
          { 
             SelectedItems.Clear();
          }
        }

Upvotes: 1

Andy Wilson
Andy Wilson

Reputation: 1383

The most straightforward method would be to create a class that inherits from ListBox: 

public class CustomListBox : ListBox
{
    public void SetSelected()
    {
        this.MouseDown += new MouseEventHandler(this.DeselectAll);
    }

    public void UnsetSelected()
    {
        this.MouseDown -= new MouseEventHandler(this.DeselectAll);
    }

    private void DeselectAll(object sender, MouseEventArgs e)
    {
        // ...
    }
}

You would use your custom list box in the same way that you would use a standard list box.

Upvotes: 1

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