用asp,net写一个简单的学生管理系统

好的，下面是一个简单的学生管理系统的ASP.NET代码：

首先是数据库连接代码：

using System.Configuration;
using System.Data.SqlClient;

public static SqlConnection GetConnection()
{
    string connectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
    SqlConnection connection = new SqlConnection(connectionString);
    connection.Open();
    return connection;
}

接下来是学生类的定义和数据库操作方法：

using System;
using System.Data;
using System.Data.SqlClient;

public class Student
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Gender { get; set; }
    public int Age { get; set; }
    public string Major { get; set; }

    public static void AddStudent(Student student)
    {
        using (SqlConnection connection = GetConnection())
        {
            string sql = "INSERT INTO Student (Name, Gender, Age, Major) VALUES (@Name, @Gender, @Age, @Major)";
            using (SqlCommand command = new SqlCommand(sql, connection))
            {
                command.Parameters.AddWithValue("@Name", student.Name);
                command.Parameters.AddWithValue("@Gender", student.Gender);
                command.Parameters.AddWithValue("@Age", student.Age);
                command.Parameters.AddWithValue("@Major", student.Major);
                command.ExecuteNonQuery();
            }
        }
    }

    public static void UpdateStudent(Student student)
    {
        using (SqlConnection connection = GetConnection())
        {
            string sql = "UPDATE Student SET Name=@Name, Gender=@Gender, Age=@Age, Major=@Major WHERE Id=@Id";
            using (SqlCommand command = new SqlCommand(sql, connection))
            {
                command.Parameters.AddWithValue("@Name", student.Name);
                command.Parameters.AddWithValue("@Gender", student.Gender);
                command.Parameters.AddWithValue("@Age", student.Age);
                command.Parameters.AddWithValue("@Major", student.Major);
                command.Parameters.AddWithValue("@Id", student.Id);
                command.ExecuteNonQuery();
            }
        }
    }

    public static void DeleteStudent(int id)
    {
        using (SqlConnection connection = GetConnection())
        {
            string sql = "DELETE FROM Student WHERE Id=@Id";
            using (SqlCommand command = new SqlCommand(sql, connection))
            {
                command.Parameters.AddWithValue("@Id", id);
                command.ExecuteNonQuery();
            }
        }
    }

    public static DataTable GetAllStudents()
    {
        using (SqlConnection connection = GetConnection())
        {
            string sql = "SELECT * FROM Student";
            using (SqlCommand command = new SqlCommand(sql, connection))
            {
                using (SqlDataAdapter adapter = new SqlDataAdapter(command))
                {
                    DataTable table = new DataTable();
                    adapter.Fill(table);
                    return table;
                }
            }
        }
    }

    public static Student GetStudentById(int id)
    {
        using (SqlConnection connection = GetConnection())
        {
            string sql = "SELECT * FROM Student WHERE Id=@Id";
            using (SqlCommand command = new SqlCommand(sql, connection))
            {
                command.Parameters.AddWithValue("@Id", id);
                using (SqlDataReader reader = command.ExecuteReader())
                {
                    if (reader.Read())
                    {
                        Student student = new Student();
                        student.Id = (int)reader["Id"];
                        student.Name = (string)reader["Name"];
                        student.Gender = (string)reader["Gender"];
                        student.Age = (int)reader["Age"];
                        student.Major = (string)reader["Major"];
                        return student;
                    }
                    else
                    {
                        return null;
                    }
                }
            }
        }
    }
}

最后是ASP.NET页面的代码：

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Student.aspx.cs" Inherits="WebApplication1.Student" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>学生管理系统</title>
</head>
<body>
    <form id="form1" runat="server">
        <div>
            <h1>学生管理系统</h1>
            <hr />
            <h2>添加学生</h2>
            <asp:TextBox ID="txtName" runat="server" placeholder="姓名"></asp:TextBox>
            <asp:TextBox ID="txtGender" runat="server" placeholder="性别"></asp:TextBox>
            <asp:TextBox ID="txtAge" runat="server" placeholder="年龄"></asp:TextBox>
            <asp:TextBox ID="txtMajor" runat="server" placeholder="专业"></asp:TextBox>
            <asp:Button ID="btnAdd" runat="server" Text="添加" OnClick="btnAdd_Click" />
            <hr />
            <h2>学生列表</h2>
            <asp:GridView ID="gvStudents" runat="server" AutoGenerateColumns="False" DataSourceID="SqlDataSource1">
                <Columns>
                    <asp:BoundField DataField="Id" HeaderText="ID" />
                    <asp:BoundField DataField="Name" HeaderText="姓名" />
                    <asp:BoundField DataField="Gender" HeaderText="性别" />
                    <asp:BoundField DataField="Age" HeaderText="年龄" />
                    <asp:BoundField DataField="Major" HeaderText="专业" />
                    <asp:ButtonField ButtonType="Button" Text="编辑" CommandName="Edit" />
                    <asp:ButtonField ButtonType="Button" Text="删除" CommandName="Delete" />
                </Columns>
            </asp:GridView>
            <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:ConnectionString %>" SelectCommand="SELECT * FROM [Student]" DeleteCommand="DELETE FROM [Student] WHERE [Id] = @Id" UpdateCommand="UPDATE [Student] SET [Name] = @Name, [Gender] = @Gender, [Age] = @Age, [Major] = @Major WHERE [Id] = @Id">
                <DeleteParameters>
                    <asp:Parameter Name="Id" Type="Int32" />
                </DeleteParameters>
                <UpdateParameters>
                    <asp:Parameter Name="Name" Type="String" />
                    <asp:Parameter Name="Gender" Type="String" />
                    <asp:Parameter Name="Age" Type="Int32" />
                    <asp:Parameter Name="Major" Type="String" />
                    <asp:Parameter Name="Id" Type="Int32" />
                </UpdateParameters>
            </asp:SqlDataSource>
        </div>
    </form>
</body>
</html>

在代码中，我们定义了一个名为“Student”的类，其中包含了学生的属性和对数据库的操作方法。在ASP.NET页面中，我们使用了GridView控件显示学生列表，并使用SqlDataSource控件进行数据库操作。在添加学生时，我们使用了一个简单的表单。