How to delete text between two texts in listbox

Question

Hi For my application, I need a code that searches for Listbox text that has the beginning and end characters

code for open text to listbox

Stream myStream = null;
OpenFileDialog openFileDialog1 = new OpenFileDialog();
openFileDialog1.InitialDirectory = "c:\\";
openFileDialog1.Filter = "txt files (*.php)|*.php|All files (*.*)|*.*";
openFileDialog1.FilterIndex = 2;
openFileDialog1.RestoreDirectory = true;
if (openFileDialog1.ShowDialog() == DialogResult.OK) {
 try {
  if ((myStream = openFileDialog1.OpenFile()) != null) {
   using(myStream) {
    textBox1.Text = File.ReadAllText(openFileDialog1.FileName);
   }
  }
 } catch (Exception ex) {
  MessageBox.Show("Error: Could not read file from disk. Original error: " + ex.Message);
 }
}
// button 2


for (int n = listBox1.Items.Count - 1; n >= 0; --n) {
 string s = listBox1.Items[n].ToString(); {
  int start = n.IndexOf("<-");
  int end = n.IndexOf("->"); {
   listBox1.Items.Remove(s);

Listbox will have text

 

for example

 

text text text

 

<-- text to be deleted

text to be deleted

text to be deleted ->

 

text text text

 

the program will delete everything written in <- -> and so it will stay

 

text text text

 

text text text

 

thank you