using System; using System.Data; using System.Data.SqlClient; public class UserManager { private string connectionString = "YourConnectionString"; public bool AuthenticateUser(string username, string password) { bool isAuthenticated = false; using (SqlConnection connection = new SqlConnection(connectionString)) { connection.Open(); string query = "SELECT COUNT(*) FROM Users WHERE Username = @Username AND Password = @Password"; using (SqlCommand command = new SqlCommand(query, connection)) { command.Parameters.AddWithValue("@Username", username); command.Parameters.AddWithValue("@Password", password); int count = (int)command.ExecuteScalar(); isAuthenticated = count > 0; } } return isAuthenticated; } public string GetUserRole(string username) { string role = string.Empty; using (SqlConnection connection = new SqlConnection(connectionString)) { connection.Open(); string query = "SELECT RoleName FROM Roles WHERE RoleID = (SELECT RoleID FROM Users WHERE Username = @Username)"; using (SqlCommand command = new SqlCommand(query, connection)) { command.Parameters.AddWithValue("@Username", username); role = (string)command.ExecuteScalar(); } } return role; } public bool HasPermission(string roleName, string permissionName) { bool hasPermission = false; using (SqlConnection connection = new SqlConnection(connectionString))

很抱歉，我之前的回答有些问题。这里是完整的示例代码：

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

public class UserManager
{
    private string connectionString = "YourConnectionString";

    public bool AuthenticateUser(string username, string password)
    {
        bool isAuthenticated = false;

        using (SqlConnection connection = new SqlConnection(connectionString))
        {
            connection.Open();

            string query = "SELECT COUNT(*) FROM Users WHERE Username = @Username AND Password = @Password";
            using (SqlCommand command = new SqlCommand(query, connection))
            {
                command.Parameters.AddWithValue("@Username", username);
                command.Parameters.AddWithValue("@Password", password);

                int count = (int)command.ExecuteScalar();
                isAuthenticated = count > 0;
            }
        }

        return isAuthenticated;
    }

    public string GetUserRole(string username)
    {
        string role = string.Empty;

        using (SqlConnection connection = new SqlConnection(connectionString))
        {
            connection.Open();

            string query = "SELECT RoleName FROM Roles WHERE RoleID = (SELECT RoleID FROM Users WHERE Username = @Username)";
            using (SqlCommand command = new SqlCommand(query, connection))
            {
                command.Parameters.AddWithValue("@Username", username);

                role = (string)command.ExecuteScalar();
            }
        }

        return role;
    }

    public bool HasPermission(string roleName, string permissionName)
    {
        bool hasPermission = false;

        using (SqlConnection connection = new SqlConnection(connectionString))
        {
            connection.Open();

            string query = "SELECT COUNT(*) FROM Permissions WHERE RoleID = (SELECT RoleID FROM Roles WHERE RoleName = @RoleName) AND PermissionName = @PermissionName";
            using (SqlCommand command = new SqlCommand(query, connection))
            {
                command.Parameters.AddWithValue("@RoleName", roleName);
                command.Parameters.AddWithValue("@PermissionName", permissionName);

                int count = (int)command.ExecuteScalar();
                hasPermission = count > 0;
            }
        }

        return hasPermission;
    }
}

请将 "YourConnectionString" 替换为您的实际数据库连接字符串。这是一个简单的用户管理类，包括身份验证、获取用户角色和检查权限的功能。您可以根据自己的需求进行修改和扩展。

希望这个示例能满足您的需求。如果还有其他问题，请随时提问！