C#

string myString = "this is an example string";<br />
<br />
//here is how you would do a substring,  start index is where you will begin the substring<br />
//length will be the length of characters to cut out<br />
string mySub = myString.Substring(startIndex, length);   //integer parameters<br />
<br />
//here is how you would get chars out<br />
char myChar = myString[index];   //index is integer 

public class MyPanel : Panel
{
  public MyPanel()
  {
    SetStyle(ControlStyles.AllPaintingInWmPaint | ControlStyles.DoubleBuffer
      | ControlStyles.UserPaint, true);
    // ...
  }
  // ..
}

private void DataGrid1_MouseUp(object sender, System.Windows.Forms.MouseEventArgs e)<br />
{<br />
	System.Drawing.Point pt = new Point(e.X, e.Y); <br />
	DataGrid.HitTestInfo hti = DataGrid1.HitTest(pt); <br />
<br />
	if(hti.Type == DataGrid.HitTestType.Cell) <br />
	{ <br />
		string str = "";<br />
		str = DataGrid1[hti.Row, hti.Column].ToString();<br />
		MessageBox.Show(str);<br />
	} 	<br />
		<br />
}

DataGrid1[hti.Row, hti.Column]=textBox1.Text;<br />
DataGrid1.Invalidate();