private void btnGetUser_Click(object sender, EventArgs e) { string username = txbUserName.Text.Trim(); List <Users> SelectList = new List <Users>(); Users user = new Users(); UserBusinessLogic userBusinessLogic = new UserBusinessLogic(); user = userBusinessLogic.GetUsersByUserrealname(username); if (user != null) { SelectList.Add(user); dgvUsers.DataSource = SelectList; } else { MessageBox.Show("该用户不存在!"); } }