C＃列表框，ownerdrawfixed，获取选定的项目

Question

my program runs a search in files and when the string is found it, it filters them in between another string and then shows them in the listbox with corresponding colors(red for bad line's determined by the second filter) and green for the good one's, the listbox shows location\\file, and on a different line the line itself.

now i want to open the file by dubbelclicking on the location\\filebut my code does not work in ownerdrawfixed (wich i need/want for the colors) i tried

string filename = listBox1.GetItemText(listBox1.selectedItem);
if (file.exists(filename))//to check if i click on a filename or on a line
  {
  try
    {
      System.diagnostics.process.start("scite.exe",filename); //open file with scite
    }
   catch
   {
     system.Diagnostics.Process.start(filename);//open file with windows default
   }

I learned that the string "filename" now contains "Datscan.Form1+MyListboxItem"

Found alot of answers on how to do it with drawmode set to normal but i need it in ownerdrawfixed.

Answer 1

Here's a minimal example I just put together that, hopefully, will help you narrow down your issues. It does not EXEcute the selection, rather it displays the selection in a label beside the ListBox. But that's just to show you that the proper value gets pulled out. Then it's only trivial to route the value to something that would EXEcute it, rather than display it.

using System.Drawing;
using System.Windows.Forms;


namespace ListBox_15948283
{
    public partial class Form1 : Form
    {
        private int ItemMargin = 5;
        private int labelCount = 0;

        public Form1()
        {
            InitializeComponent();
            ListBox lb = new ListBox();//initialize a new ListBox
            lb.DrawMode = DrawMode.OwnerDrawFixed;//lets meet YOUR requirement of OwnerDrawFixed
            lb.Location = new Point(25, 25);//position the ListBox
            lb.DrawItem += Lb_DrawItem;//give it a Draw event handler
            lb.MeasureItem += Lb_MeasureItem;//give it a MeasureItem event handler
            lb.Name = "lstbx_Yep";//give the listbox a name so we can call it later
            lb.Items.Add("Option 1");//add an option
            lb.Items.Add("Option 2");//add an option
            lb.Items.Add("Option 3");//add an option
            lb.Items.Add("Option 4");//add an option
            lb.MouseDoubleClick += Lb_MouseDoubleClick;//add a doubleClick event handler on the ListBox
            this.Controls.Add(lb);//add the listbox to the form
        }

        private void Lb_MouseDoubleClick(object sender, MouseEventArgs e)
        {
            ListBox lb = ((ListBox)this.Controls.Find("lstbx_Yep", false)[0]);//get the listbox
            Label lbl = new Label();//make a label to display the result
            lbl.Location = new Point(150, (labelCount * 25) + 50);//position the label
            lbl.Text = lb.SelectedItem.ToString();//get the selected item
            this.Controls.Add(lbl);//add the label to the form
            labelCount++;

        }

        /*
         * Code below taken from
         * http://csharphelper.com/blog/2014/11/make-an-owner-drawn-listbox-in-c/
         */
        private void Lb_MeasureItem(object sender, MeasureItemEventArgs e)
        {
            // Get the ListBox and the item.
            ListBox lst = sender as ListBox;
            string txt = (string)lst.Items[e.Index];

            // Measure the string.
            SizeF txt_size = e.Graphics.MeasureString(txt, this.Font);

            // Set the required size.
            e.ItemHeight = (int)txt_size.Height + 2 * ItemMargin;
            e.ItemWidth = (int)txt_size.Width;
        }

        private void Lb_DrawItem(object sender, DrawItemEventArgs e)
        {
            // Get the ListBox and the item.
            ListBox lst = sender as ListBox;
            string txt = (string)lst.Items[e.Index];

            // Draw the background.
            e.DrawBackground();

            // See if the item is selected.
            if ((e.State & DrawItemState.Selected) ==
                DrawItemState.Selected)
            {
                // Selected. Draw with the system highlight color.
                e.Graphics.DrawString(txt, this.Font,
                    SystemBrushes.HighlightText, e.Bounds.Left,
                        e.Bounds.Top + ItemMargin);
            }
            else
            {
                // Not selected. Draw with ListBox's foreground color.
                using (SolidBrush br = new SolidBrush(e.ForeColor))
                {
                    e.Graphics.DrawString(txt, this.Font, br,
                        e.Bounds.Left, e.Bounds.Top + ItemMargin);
                }
            }

            // Draw the focus rectangle if appropriate.
            e.DrawFocusRectangle();
        }
    }
}