方法重载 Visual Studio

Question

我正在做一个项目。该项目涉及一个数据库，其中包含一个名为“Customers”的表。在同一个项目中，我有一个名为“frmAddNewCustomer”的表单。此表单包含与客户相关的 9 个属性。有一个按钮，单击该按钮时会包含允许将这些属性分别输入数据库的代码。

我还有一个名为“CustomerDAL”的类，它允许我在数据库表上执行任务（插入、更新、删除等），并且该类包含我用来从“frmAddNewCustomer”表单向数据库输入数据的方法。

最后，我有一个名为“CustomerModel”的类，它代表数据库中的一条记录。在 CustomerDAL 类中，前面提到的方法（允许我通过 UI 表单向数据库输入数据的方法）的参数是从 CustomerModel 类创建的对象。我的问题是，在 UI 表单中，它表示该方法没有 9 个参数的重载。

这是客户模型类：

public int CustomerID { get; set; }
public string Title { get; set; }
public string Forename { get; set; }
public string Surname { get; set; }
public string Email { get; set; }
public string Streetname { get; set; }

public string Town { get; set; }
public string County { get; set; }
public string Postcode { get; set; }
public string WeddingGiftList { get; set; }

public CustomerModel( string title, string forename, string surname, string email, string  streetname,string town, string county, string postcode, string weddingGiftlist)
{
        Title = title;
        Forename = forename;
        Surname = surname;
        Email = email;
        Streetname = streetname;
        Town = town;
        County = county;
        Postcode = postcode;
        WeddingGiftList = weddingGiftlist;
}

public CustomerModel()
{
}

这是 CustomerDAL 类：

 private static string _connectionString =       ConfigurationManager.ConnectionStrings["SimpsonsConnection"].ConnectionString;

    public static int AddNewCustomer(CustomerModel newCustomer)
    {
        using (SqlConnection connection = new SqlConnection(_connectionString))
        {
            connection.Open();

            string sqlQuery = string.Format("INSERT INTO [Customer] VALUES('{0}', '{1}', '{2}', '{3}', '{4}', '{5}','{6}','{7}','{8}')", newCustomer.Title, newCustomer.Forename, newCustomer.Surname, newCustomer.Email, newCustomer.Streetname, newCustomer.Town, newCustomer.County, newCustomer.Postcode, newCustomer.WeddingGiftList);

            SqlCommand insertCommand = new SqlCommand(sqlQuery, connection);

            int rowsAffected = insertCommand.ExecuteNonQuery();

            connection.Close();

            return rowsAffected;
        }
    }

//this is the UI forms click event on the button:

//this is to add the customer details to the database when the 'Create button is clicked'
   if ( cmbxTitle.Text != "" || txtForename.Text != "" || txtSurname.Text != "" || txtEmail.Text != "" || txtStreetName.Text != "" || txtTown.Text != "" || txtCounty.Text != "" || txtPostCode.Text != "" || cmbxWeddingGiftList.Text != "")
        {
            int rowsAffected = CustomerDAL.AddNewCustomer(cmbxTitle.Text, txtForename.Text, txtSurname.Text, txtEmail.Text, txtStreetName.Text, txtTown.Text, txtCounty.Text, txtPostCode.Text, cmbxWeddingGiftList.Text);

            if(rowsAffected == 1)
            {
                MessageBox.Show("Customer has been added successfully");

                Form myNextScreen = new frmMenu();
                myNextScreen.Show();
            }
            else
            {
                MessageBox.Show("Customer was not able to be registered. Please re-enter details carefully");
            }
        }
        else
        {
            lblInfo.Visible = true;
            MessageBox.Show("Please enter all details");
        }

在 UI 表单中，我的错误是当我从 CustomerDAL 类中引用“AddNewCustomer”方法时。

我只是不确定如何解决这个错误，因为我认为我有 9 个参数？ 如果你能帮我解决这个问题，那将意义重大，因为我对 C# 中的数据库还比较陌生

Answer 1

在我看来，你的问题可能在于没有定义对象

int rowsAffected = CustomerDAL.AddNewCustomer(new CustomerModel{....});

Answer 2

而不是这个

int rowsAffected = CustomerDAL.AddNewCustomer(cmbxTitle.Text, txtForename.Text, txtSurname.Text, txtEmail.Text, txtStreetName.Text, txtTown.Text, txtCounty.Text, txtPostCode.Text, cmbxWeddingGiftList.Text);

有这个

var newCustomer = new Customer
{
    Title  = cmbxTitle.Text,
//rest of customer properties
};
int rowsAffected = CustomerDAL.AddNewCustomer(newCustomer)