کار با کلاس StringInfo در سی شارپ

[CSHARP]using System;
using System.Windows.Forms;

namespace stringApplications
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
System.Globalization.StringInfo obj = new System.Globalization.StringInfo("http://softafzar.net");
private void Form1_Load(object sender, EventArgs e)
{
this.Text = "http://softafzar.net";
txt_setStr.Text = this.Text;
}

    private void btn_getLength_Click(object sender, EventArgs e)
    {
        int length;
        length = obj.LengthInTextElements;
        MessageBox.Show("the length of text element is " + Convert.ToInt16(length));
    }

    private void btn_getstr_Click(object sender, EventArgs e)
    {
        string str;
        str = obj.String;
        MessageBox.Show("the string is " + str);
    }

    private void btn_setStr_Click(object sender, EventArgs e)
    {
        string str;
        str = txt_setStr.Text;
        obj.String = str;
        MessageBox.Show("the string is set to " + str);
    }

    private void btn_substring_Click(object sender, EventArgs e)
    {
        int startingIndex;
        int count;
        string str;
        startingIndex = Convert.ToInt16(txt_startIndex.Text);
        count = Convert.ToInt16(txt_count.Text);
        str = obj.SubstringByTextElements(startingIndex, count);
        MessageBox.Show("the substring is " + str);
    }
}

}
[/CSHARP]