Question

我即将放弃这个，我正在尝试将一个字符串传递给另一个类，并在该类中将它保存到List但它不会这样做。我知道List存在并且工作，因为我创建了一个按钮，将一个字符串放入该列表并在列表框中显示它。但由于某种原因，我不能让它在传递的字符串上工作。

这是两个winforms，因为一个让用户提供信息然后它被处理并传递给另一个类，然后应该保存到List中，然后我要求更新，它应该在列表框中显示List。

Mainform（带有列表框的那个）

public partial class MainForm : Form
{        

    List<string> m_customers = new List<string>();    


    public MainForm()
    {
        InitializeComponent();            
    }


    public void StringToList(string strnew)
    {           
        m_customers.Add(strnew);
        Updatelistbox();

        foreach (string custom in m_customers)
        {
            lstRegistry.Items.Add(custom);
        }
    }

    private void strtest(string strnew)
    {
        string userinfo = strnew;
        m_customers.Add(userinfo);
    }

    private void Updatelistbox()
    {
        lstRegistry.Items.Clear();
        for (int index = 0; index < m_customers.Count; index++)
        {
            lstRegistry.Items.Add(m_customers[index]);
        }
    }      

    private void button1_Click(object sender, EventArgs e)
    {
        using (ContactForm frm = new ContactForm())
        {
            frm.ShowDialog();
        }
    }


    private void button2_Click(object sender, EventArgs e)
    {                 
        lstRegistry.Items.Add("Hey this works atleast...");

        m_customers.Add("add this to List");  //This works as this line becomes more and more.
        foreach (string custom in m_customers)
        {
            lstRegistry.Items.Add(custom);
        }        
    }
}

输入形式

public partial class ContactForm : Form
{
    private ContactFiles.Contact m_contact = new ContactFiles.Contact();
    private ContactFiles.Email m_email = new ContactFiles.Email();
    private ContactFiles.Phone m_phone = new ContactFiles.Phone();
    private ContactFiles.Adress m_adress = new ContactFiles.Adress();

    private bool m_closeForm;

    public ContactForm()
    {

        InitializeComponent();

        InitializeGUI();
    }

    private void InitializeGUI()
    {
        txtFirstName.Text = string.Empty;
        txtLastName.Text = string.Empty;
        txtHomePhone.Text = string.Empty;
        txtCellPhone.Text = string.Empty;
        txtEmailBusiness.Text = string.Empty;
        txtEmailPrivate.Text = string.Empty;
        txtStreet.Text = string.Empty;
        txtCity.Text = string.Empty;
        txtZipCode.Text = string.Empty;
        FillCountryComboBox();
        cmbCountries.Items.AddRange(FillCountryComboBox()); cmbCountries.SelectedIndex = 5;
        m_closeForm = true;
    }


    public string[] FillCountryComboBox()
    {
        string[] m_countryStrings = Enum.GetNames(typeof(Countries));

        for (int index = 0; index < m_countryStrings.Length - 1; index++)
        {
            m_countryStrings[index] = m_countryStrings[index].Replace("_", " ");
        }
        return m_countryStrings;
    }

    private void btnOK_Click(object sender, EventArgs e)
    {           
        string a_country = cmbCountries.SelectedItem.ToString();
        var oAdress = new ContactFiles.Adress(txtStreet.Text, txtCity.Text, txtZipCode.Text, a_country);
        string adresslist = oAdress.ToString();            
        var oEmail = new ContactFiles.Email(txtEmailBusiness.Text, txtEmailPrivate.Text);
        string emaillist = oEmail.ToString();            
        var oPhones = new ContactFiles.Phone(txtHomePhone.Text, txtCellPhone.Text);
        string phonelist = oPhones.ToString();
        //This is actually working, the string is passed OK.            
        //MainForm strin = new MainForm();            
        var oContact = new ContactFiles.Contact(txtFirstName.Text, txtLastName.Text);
        string namelist = oContact.ToString();

        //Create string from input and send to MainForm.StringToList()
        MainForm instance = new MainForm();
        string strnew = string.Format("{0,-3} {1, -10} {2, -20} {3, -30}", namelist, phonelist, emaillist, adresslist);
        instance.StringToList(strnew);


        this.Close();
    }

    private ContactFiles.Contact Contacts
    {
        get { return m_contact; }
        set
        {
            if (value != null)
                m_contact = value;                
        }
    }

    public ContactFiles.Email Email
    {
        get { return m_email; }
        set 
        {
            if (value != null)
            m_email = value; 
        }
    }

    public ContactFiles.Phone Phone
    {
        get { return m_phone; }
        set
        {
            if (value != null)
                m_phone = value;
        }
    }

    private ContactFiles.Adress Adress
    {
        get { return m_adress; }
        set
        {
            if (value != null)
                m_adress = value;
        }
    }

    private void ContactForm_FormClosing(object sender, FormClosingEventArgs e)
    {
        if (m_closeForm)
            e.Cancel = false;  //Close the Contact form.
        else
            e.Cancel = true; //Do not close (user has chosen Cancel)
    }      
}

有一些你可以看到更多的类来处理包含构造函数的用户输入，但它们都可以工作，因为我可以从所有用户输入创建字符串但是然后我失去了很大的时间为我和它现在3天和我仍然找不到问题。：'（

关于如何解决我的问题的任何想法？！？我只是找不到问题。

Answer 1

 MainForm instance = new MainForm();
    string strnew = string.Format("{0,-3} {1, -10} {2, -20} {3, -30}", namelist, phonelist, emaillist, adresslist);
    instance.StringToList(strnew);

这很糟糕。您正在创建主表单的新实例（使用新列表）而不是使用旧表单。在Contact表单的结构中传递列表并在那里添加值。

List<string> m_customers;

public ContactForm(List<string> list) : this()
{
   m_customers = list;
}

创建表单代码

private void button1_Click(object sender, EventArgs e)
{
    using (ContactForm frm = new ContactForm(m_customers))
    {
        frm.ShowDialog();
    }
}

现在您可以将值添加到列表中。

更新：将您的StringToList方法带到联系表单，将其设为私有，并在联系表单实例中使用它。

Answer 2

您可以尝试使主表单具有输入表单的实例，反之亦然。主要形式最终将保留数据。让输入表单成为新实例并以该方式返回值。

变量不接受从另一个类传递的值

2 个答案: