C#图书管理系统全源代码！

源代码，一看就知道！开头部分，下面的自己下载下来看吧！ public partial class LoginForm : Form{ public static string uacc; public static string upsw; public static string uname; public static string usex; public static string upart; public static string uright; public LoginForm() { InitializeComponent(); } private void loginbtn_Click(object sender, EventArgs e) { if (this.useracctxt.Text.Trim() == "" && this.pswtxt.Text == "") { MessageBox.Show("请输入您的用户名和密码！", "提示！"); return; } try { string sql; sql = "select * from tb_user where uacc='" + this.useracctxt.Text + "' and upsw='" + this.pswtxt.Text + "'"; OleDbDataReader dr = DBHelp.OleReader(sql); dr.Read(); if (dr.HasRows) { uacc = this.useracctxt.Text; upsw = this.pswtxt.Text; uname = dr["uname"].ToString(); usex = dr["usex"].ToString(); upart = dr["upart"].ToString(); uright = dr["uright"].ToString(); MainForm af = new MainForm(this); this.Hide(); this.useracctxt.Clear(); this.pswtxt.Clear(); af.Show(); } else { MessageBox.Show("账号或密码错误！", "提示！"); this.useracctxt.Clear(); this.pswtxt.Clear(); this.useracctxt.Focus(); } } catch (Exception) { MessageBox.Show("数据库无法连接！", "警告！"); } } private void cancelbtn_Click(object sender, EventArgs e) { Application.Exit(); } private void Logi