private void button1_Click(object sender, System.EventArgs e)
{
openFileDialog1.ShowDialog ();
FileStream fr=new FileStream(openFileDialog1.FileName ,FileMode.OpenOrCreate ,FileAccess.Read);
byte [] filebtye=new byte[fr.Length ];
fr.Read(filebtye,0,Convert.ToInt32 (fr.Length) );
char [] filechar=new char [fr.Length ];
Encoding myencode=Encoding.GetEncoding (932);
myencode.GetChars (filebtye,0,Convert.ToInt32 (fr.Length) ,filechar,0);
string s= new string (filechar);
fr.Close ();
richTextBox1.Text =s;
}