ListBox不显示任何结果
本文关键字:结果 任何 显示 ListBox | 更新日期: 2023-09-27 18:17:28
我试图添加一个数组的字符串持有信息的人的ListBox,但我不能让它显示任何东西,我真的不知道为什么。
这是当单击将联系人添加到列表的按钮时调用的第一个类。
public partial class MainForm : Form
{
private ContactManager m_contacts;
public MainForm()
{
InitializeComponent();
m_contacts = new ContactManager();
InitializeGUI();
}
private void InitializeGUI()
{
txtFirstName.Text = string.Empty;
txtLastName.Text = string.Empty;
txtStreet.Text = string.Empty;
txtCity.Text = string.Empty;
txtZipCode.Text = string.Empty;
cmbCountry.Items.AddRange(Enum.GetNames(typeof(Countries)));
cmbCountry.DropDownStyle = ComboBoxStyle.DropDownList;
cmbCountry.SelectedIndex = (int)Countries.Sverige;
UpdateGUI();
}
private bool ReadInput(out Contact contact)
{
// skapar ett lokalt objekt av Contact-klassen
contact = new Contact();
// Lägger in ReadAdress till ett objekt i klassen Adress.
Address adr = ReadAddress();
contact.AddressData = adr; // skickar adress till contact-objekt
//bool readNameOK = ReadName();
// ReadName är OK så skickas det till AddContact.
if (ReadName())
{
m_contacts.AddContact(contact);
}
return ReadName();
} // ReadInput
private bool ReadName()
{
Contact contact = new Contact();
contact.FirstName = txtFirstName.Text;
contact.LastName = txtLastName.Text;
bool firstname = false;
bool lastname = false;
if (!InputUtility.ValidateString(contact.FirstName))
{
MessageBox.Show("You must enter a first name with atleast one character (not a blank)", "Error!",
MessageBoxButtons.OK, MessageBoxIcon.Error);
txtFirstName.Focus();
txtFirstName.Text = " ";
txtFirstName.SelectAll();
firstname = false;
}
else if (!InputUtility.ValidateString(contact.LastName))
{
MessageBox.Show("You must enter a last name with atleast one character (not a blank)", "Error!",
MessageBoxButtons.OK, MessageBoxIcon.Error);
txtLastName.Focus();
txtLastName.Text = " ";
txtLastName.SelectAll();
lastname = false;
}
return firstname && lastname;
}
private Address ReadAddress()
{
Address address = new Address();
address.Street = txtStreet.Text;
address.City = txtCity.Text;
address.ZipCode = txtZipCode.Text;
address.Country = (Countries)cmbCountry.SelectedIndex;
return address;
}
private void button1_Click(object sender, EventArgs e)
{
Contact contact;
if (ReadInput(out contact))
{
UpdateGUI();
}
}
private void UpdateGUI()
{
lstContacts.Items.Clear();
lstContacts.Items.AddRange(m_contacts.GetContactsInfo());
lblCount.Text = m_contacts.Count().ToString();
}
private void lstContacts_SelectedIndexChanged(object sender, EventArgs e)
{
UpdateContactInfoFromRegistry();
}
private void UpdateContactInfoFromRegistry()
{
Contact contact = m_contacts.GetContact(lstContacts.SelectedIndex);
cmbCountry.SelectedIndex = (int)contact.AddressData.Country;
txtFirstName.Text = contact.FirstName;
txtLastName.Text = contact.LastName;
txtCity.Text = contact.AddressData.City;
txtStreet.Text = contact.AddressData.Street;
txtZipCode.Text = contact.AddressData.ZipCode;
}
}
这个类然后调用这个类
public class ContactManager
{
private List<Contact> m_contactRegistry;
public ContactManager()
{
m_contactRegistry = new List<Contact>();
}
public int Count()
{
int count = m_contactRegistry.Count();
return count;
}
public bool CheckIndex(int index)
{
if (index >= 0 && index < m_contactRegistry.Count())
return true;
else return false;
}
public bool AddContact(string firstName, string lastName, Address addressIn)
{
Contact contactObj = new Contact();
bool result = false;
if (!result)
{
contactObj.FirstName = firstName;
contactObj.LastName = lastName;
contactObj.AddressData = addressIn;
m_contactRegistry.Add(contactObj);
result = true;
}
return result;
}
public bool AddContact(Contact contactIn)
{
if (contactIn == null)
{
return false;
}
else
{
m_contactRegistry.Add(contactIn);
return true;
}
}
public bool changeContact(Contact contactIn, int index)
{
if (CheckIndex(index))
{
Contact contact = (Contact)m_contactRegistry[index];
//contact.ToString = contactIn;
return true;
}
else return false;
}
public bool DeleteContact(int index)
{
if (CheckIndex(index))
{
m_contactRegistry.RemoveAt(index);
return true;
}
else return false;
}
public Contact GetContact(int index)
{
if (!CheckIndex(index))
return null;
else return m_contactRegistry[index];
}
public string[] GetContactsInfo()
{
string[] strInfoStrings = new string[m_contactRegistry.Count];
int i = 0;
foreach (Contact contactObj in m_contactRegistry)
{
strInfoStrings[i++] = contactObj.ToString();
}
return strInfoStrings;
}
}
任何关于为什么数组不会显示在列表框中的帮助将非常感激,谢谢。
您的ReadName()
总是返回false,因为它永远不会添加联系人。
编辑:更清晰的代码
private Contact ReadInput()
{
Contact contact = new Contact();
contact.FirstName = txtFirstName.Text;
contact.LastName = txtLastName.Text;
contact.AddressData = new Address
{
Street = txtStreet.Text,
City = txtCity.Text,
ZipCode = txtZipCode.Text,
Country = (Countries) cmbCountry.SelectedIndex
};
return contact;
}
private bool ValidateContact(Contact contact)
{
if ( !InputUtility.ValidateString( contact.FirstName ) )
{
MessageBox.Show( "You must enter a first name with atleast one character (not a blank)", "Error!", MessageBoxButtons.OK, MessageBoxIcon.Error );
txtFirstName.Focus();
txtFirstName.Text = " ";
txtFirstName.SelectAll();
return false;
}
else if ( !InputUtility.ValidateString( contact.LastName ) )
{
MessageBox.Show( "You must enter a last name with atleast one character (not a blank)", "Error!", MessageBoxButtons.OK, MessageBoxIcon.Error );
txtLastName.Focus();
txtLastName.Text = " ";
txtLastName.SelectAll();
return false;
}
return true;
}
private void button1_Click( object sender, EventArgs e )
{
Contact contact = ReadInput();
if ( ValidateContact( contact ) )
{
m_contacts.AddContact(contact);
UpdateGUI();
}
}