我做的课程设计，这里和数据库连接，代码显示没有错误，可是一启动界面是空白的，这是为什么？急急急

Question

private void btnSure_Click(object sender, EventArgs e)
{
string userName = tbName.Text;
string password = tbPwd.Text;
string connString = @"Data Source=.\sqlexpress;Initial Catalog=PersonalFinance;Integrated Security=true";
SqlConnection conn = new SqlConnection(connString);
string sql = String.Format("select count(*)from [UserInfo] where userName='{0}'and password='{1}'",userName ,password);
try
{

conn.Open ();
SqlCommand comm=new SqlCommand (sql,conn);
int n =(int)comm.ExecuteScalar();
if (n==1)

{

this .DialogResult =DialogResult .OK ;
this.Tag =true ;
MessageBox.Show("欢迎进入小金库个人理财管理系统！", "登陆成功", MessageBoxButtons.OK,
MessageBoxIcon.Information);
}
else
{
MessageBox.Show("您输入的用户名或密码错误请重试！", "登录失败",
MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
this.Tag =false ;
}

        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message,"数据库出错！",
                MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
             this .Tag =false ;                      
        }   
        finally
        {
            conn.Close();
        } 
    }

Answer 1