string conStr = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=F:\access\DBCommunity.mdb";//;Data Source=path; Jet OLEDB:Database Password=pwd;//
                OleDbConnection con = new OleDbConnection(conStr);
                con.Open();
                string cmdStr = "select * from 操作用户 where 用户名称='" + this.用户名称TextBox.Text + "' and 用户密码='" + this.用户密码TextBox.Text + "'";
               
                OleDbCommand cmd = new OleDbCommand(cmdStr, con);
                OleDbDataReader reader = cmd.ExecuteReader();
                if (reader.Read())　
                {
                    MainForm newForm = new MainForm();
                    newForm.Show();　
                    this.Hide();　            
                }
                else
                {

                    Times++;
                    if (Times == 3)
                    {
                        MessageBox.Show("密码错误3次，请查证后再登录！");
                        this.Close();
                    }
                    else
                    {
                        MessageBox.Show("用户名或密码错误！");
                                            }

                }
                reader.Close();
                cmd.Connection.Close();
                con.Close();
            }
        }

一直连接不上

看了半天终于找到问题所在了，数据库的路径有问题，改下路径就可以连上了