图4.1
该界面是学生成绩管理系统的登录界面，可以选择作为学生，管理员或者教师身份登录。每一个进入系统的人都会看到当前的时间，在登录时只有用户名，密码，与身份相符合时才能进入系统，否则登录无法成功。 using System;
using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text;
using System.Threading.Tasks; using System.Windows.Forms; using System.Data.SqlClient;
namespace WindowsFormsApplication1 {
public partial class Form1 : Form {
static public string sn, sub; public Form1() {
InitializeComponent(); }
Form2 fr2 = new Form2(); Form3 fr3 = new Form3(); Form4 fr4 = new Form4();
private void Form1_Load(object sender, EventArgs e) {
timer1.Start(); }
private void label1_Click(object sender, EventArgs e) {
}
private void button1_Click(object sender, EventArgs e) {
string constr = \ID=ywj;Initial Catalog=studentscore;Data Source=YANJING\; SqlConnection conn = new SqlConnection(constr); conn.Open();
if (textname.Text == \ || textpassword.Text == \) MessageBox.Show(\信息不全，请不要遗漏信息！\); if (rbtnmanager.Checked) {
string cstr = \类别='管理员' and 用户名='\ + textname.Text.Trim() + \密码='\ + textpassword.Text.Trim() + \; SqlCommand comm = new SqlCommand(cstr, conn); SqlDataReader dr = comm.ExecuteReader(); if (dr.Read()) {
sn = textname.Text.Trim(); fr4.Show(); this.Visible = false; ; } else {
MessageBox.Show(\密码或用户名出错，请重新输入！\); textname.Text = \; textpassword.Text = \; } }
if (rbtnteacher.Checked) {
string cstr = \类别='教师' and 用户名='\ + textname.Text.Trim() + \密码='\ + textpassword.Text.Trim() + \; SqlCommand comm = new SqlCommand(cstr, conn); SqlDataReader dr = comm.ExecuteReader(); if (dr.Read()) {
sn = textname.Text.Trim(); sub = dr.GetValue(3).ToString(); fr3.Show(); this.Visible = false;
} else {
MessageBox.Show(\密码或用户名出错，请重新输入！\); textname.Text = \; textpassword.Text = \; } }
if (rbtnstudent.Checked) {
string cstr = \类别='学生' and 用户名='\ + textname.Text.Trim() + \密码='\ + textpassword.Text.Trim() + \; SqlCommand comm = new SqlCommand(cstr, conn); SqlDataReader dr = comm.ExecuteReader(); if (dr.Read()) {
sn = textname.Text.Trim(); fr2.Show(); this.Visible = false;
} else {
MessageBox.Show(\密码或用户名出错，请重新输入！\); textname.Text = \; textpassword.Text = \; } }
conn.Close(); conn.Dispose(); }
private void button2_Click(object sender, EventArgs e) {
Application.Exit(); }
private void timer1_Tick(object sender, EventArgs e) {
label4.Text = \当前时间：\ + DateTime.Now.ToLongDateString() + \ + DateTime.Now.ToLongTimeString(); }
} }
4.2学生成绩管理
图4.2
设计过程：
此部分主要针对学生信息的管理，可以查询学生的所有成绩信息，实现成绩的添加、删除、修改、计算平均分等功能。还可以修改当前用户下的密码。
private void Form2_Load(object sender, EventArgs e) {
label1.Text = Form1.sn + \同学，欢迎你进入成绩管理系统！\; timer1.Start();
groupBox1.Visible = false; groupBox2.Visible = false; }
private void button1_Click(object sender, EventArgs e) {
}
private void button3_Click(object sender, EventArgs e)
{
// string constr = \ID=BINIANDOUKOU\\administrator;Initial Catalog=studentscore;Data Source=BINIANDOUKOU\\\\SQLEXPRESS\
//SqlConnection conn = new SqlConnection(constr); //conn.Open();
//SqlDataAdapter da = new SqlDataAdapter(\姓名=\
//DataSet ds = new DataSet(); //da.Fill(ds, \ //dataGridView1.DataSource = ;
}
private void toolStripButton1_Click(object sender, EventArgs e) {
dataGridView1.Visible = true; groupBox1.Visible = false; groupBox2.Visible = false;
string constr = \ID=ywj;Initial Catalog=studentscore;Data Source=YANJING\; SqlConnection conn = new SqlConnection(constr); conn.Open();
SqlDataAdapter da = new SqlDataAdapter(\姓名='\ + Form1.sn.Trim() + \, conn);//----详细信息 DataSet ds = new DataSet(); da.Fill(ds, \);
dataGridView1.DataSource = ds.Tables[\].DefaultView; conn.Close(); conn.Dispose(); }
private void toolStripButton2_Click(object sender, EventArgs e) {
}
private void toolStripButton4_Click(object sender, EventArgs e) {
groupBox1.Visible = true; }
private void button1_Click_1(object sender, EventArgs e) {
string constr = \ID=ywj;Initial Catalog=studentscore;Data Source=YANJING\; SqlConnection conn = new SqlConnection(constr); conn.Open();
if (textnpd.Text != textpassword.Text) { MessageBox.Show(\密码输入有
