Question

I have two listboxes with several data, ListBox1 have this format:

C:\Users\Charlie\Desktop\Trials\Trial0004COP.txt

and in my ListBox2:

Trial0004COP

How can I check if Trial0004COP exists in my listbox1? I used Contain() but it doesn’t work.

Answer 1

What about:

bool found = listBox1.Items.Cast<string>()
                           .Where(x => x.Contains("Trial0004COP"))
                           .Any();

Or to make it more accurate use String.EndsWith() method but you also have to add ".txt" if you want to make it works:

bool found = listBox1.Items.Cast<string>()
                           .Where(x => x.EndsWith("Trial0004COP.txt"))
                           .Any();

Edit :

Hi Fuex, I’m using OpenFileDialog to select a file, then this file is
added to my listbox1 with all the Directory name. In my listbox2 I
read another file that contains several Trials000″”” and add them to
it, I want to know if the file that I selected from the open dialog
exist in my listboz2

Yes can do it in this way:

bool found = false;
if(openFileDialog.ShowDialog() == DialogResult.OK){
   found = listBox.Items.Cast<string>()
                        .Where(x => x.EndsWith(openFileDialog.FileName))
                        .Any();

   if(!found)
      MessageBox.Show(openFileDialog.FileName + " doesn't exist in listBox1"); //show a message
}