private void button1_Click(object sender, EventArgs e)
{
SqlConnection MyConnection = new SqlConnection();
MyConnection.ConnectionString = ConnectionClass.Connection_Path();
MyConnection.Open();
string somut = "select a.username from KULLANICI AS A ";
SqlDataAdapter da = new SqlDataAdapter(somut, MyConnection);
DataTable dt = new DataTable();
da.Fill(dt);
dataGridView1.DataSource = dt;
label1.Text = dataGridView1.Rows[dataGridView1.CurrentRow.Index].Cells[0].Value.ToString();
MyConnection.Close();
}