读取数据库出错，方法或操作未实现 [英] Error reading the database, method or operation is not implemented

问题描述

所以在修复了一个错误后，我得到 studentHelperClass.Form1.cmbBox 由于其保护级别而无法访问我在启动我的程序时遇到了这个错误 Error reading the database, method or操作没有被我的错误标签实现.

So after fixing an error where I was getting studentHelperClass.Form1.cmbBox is inaccessible due to its protection level I got this error when I launched my prorgam Error reading the database, method or operation is not implemented by my error label.

这是我的代码:

public partial class Form1 : Form
    {
        MySqlConnection conn; // connection object;
        string connstring = "server=localhost;user Id=root;database=collegesystem;Convert Zero Datetime=True ";

        public Form1()
        {
            InitializeComponent();
            connection();
            selectStudent();
        }


        private void selectStudent()
        {
            try
            {
                studentHelperClass.studentHC.insertMethod();
            }

            catch (Exception err)
            {
                lblInfo.Text = " Error reading the database.";
                lblInfo.Text += err.Message;
            }
        }

那是表单的代码，下面是带有方法的类

That is the code for the form, the following is the class with the method

class studentHC : Form1
    {
        public studentHC()
        {
            InsertMethod();
        }

        private void InsertMethod()
        {
            MySqlConnection conn; // connection object;
            string connstring = "server=localhost;user Id=root;database=collegesystem;Convert Zero Datetime=True ";
            conn = new MySqlConnection(connstring);
            conn.Open();
            using (var command = new MySqlCommand("SELECT * FROM person", conn))
            {
                using (var myReader = command.ExecuteReader())
                {
                    cmbBox.Items.Add(myReader["personID"]);
                }
            }
        }

        internal static void insertMethod()
        {
            throw new NotImplementedException();
        }
    }

任何输入将不胜感激

好的，所以我摆脱了

internal static void insertMethod()
{
    throw new NotImplementedException();
}

我变了

public studentHC()
{
    InsertMethod();
}

private void InsertMethod()

到

public studentHC()
{
    insertMethod();
}

private void insertMethod()

现在它说studentHelperClass.studentHC.insertMethod()'由于其保护级别而无法访问

推荐答案

用这个替换你的 studentHC 类

replace your studentHC class with this

class studentHC : Form1
    {
        public studentHC()
        {
            InsertMethod();
        }

        public static void InsertMethod()
        {
            MySqlConnection conn; // connection object;
            string connstring = "server=localhost;user Id=root;database=collegesystem;Convert Zero Datetime=True ";
            conn = new MySqlConnection(connstring);
            conn.Open();
            using (var command = new MySqlCommand("SELECT * FROM person", conn))
            {
                using (var myReader = command.ExecuteReader())
                {
                    cmbBox.Items.Add(myReader["personID"]);
                }
            }
        }

    }

然后替换

studentHelperClass.studentHC.insertMethod();

与

studentHelperClass.studentHC.InsertMethod();

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