来自一个ComboBox的多个ValueMembers C＃

Question

我想在组合框中为value成员分配多个字段。从代码中可以看出，分配给value成员的当前字符串是“title”，在cboCustomers_SelectionChangeCommited事件中，您可以看到已为文本框分配了所选值。

我希望实现的是将另外两个字段分配给值成员（“firstname”，“lastname”），并为另外两个文本框分配这些值。

我希望我已经清楚了。如果没有，请说明，我将尝试重新解释。

 private void Form3_Load(object sender, EventArgs e)
                    {
                        try
                        {
                            dbConn = new OleDbConnection(conString);
                            sql = @"SELECT customer.title, firstname, lastname, product.name, account.balance
                                  FROM (account INNER JOIN customer ON account.custid = customer.custid) INNER JOIN product ON account.prodid = product.prodid;";

                            daItems = new OleDbDataAdapter(sql, dbConn);
                            daItems.Fill(dtAccBal);


                            cboCustomers.DataSource = (dtAccBal);
                            cboCustomers.DisplayMember = "firstname";
                            cboCustomers.ValueMember = "title";
                            cboCustomers.SelectedIndex = -1;

                        }
                        catch (Exception ex)
                        {
                            MessageBox.Show(ex.Message, "Error!");
                        }
                    }


                    private void cboCustomers_SelectionChangeCommitted(object sender, EventArgs e)
                    {
                        if (cboCustomers.SelectedIndex > -1)
                        {
                            try
                            {
                                txtTitle.Text = cboCustomers.SelectedValue.ToString();



                            }
                            catch (Exception ex)
                            {
                                MessageBox.Show(ex.Message, "Error!");
                            }
                        }
                    }
                }

Answer 1

您可以使用实现INotifyPropertyChanged接口的对象并将DataBindings添加到TextBox中。

示例：

实施INotifyPropertyChanged

的类人员

public class Person : INotifyPropertyChanged
{
    private string _firstName;
    public string FirstName
    {
        get { return _firstName; }
        set
        {
            if (value == _firstName) return;
            _firstName = value;
            OnPropertyChanged();
        }
    }

    private string _lastName;
    public string LastName
    {
        get { return _lastName; }
        set
        {
            if (value == _lastName) return;
            _lastName = value;
            OnPropertyChanged();
        }
    }

    public override string ToString() => $"{FirstName} {LastName}";

    public event PropertyChangedEventHandler PropertyChanged;
    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

在表单ComboBox“comboBoxPeople”和两个TextBoxes“textBoxFirstName”，“textBoxLastName”上添加。

更改表单的构造函数：

public Form1()
{
    InitializeComponent();

    var people = new BindingList<Person> {
        new Person() { FirstName = "Peter", LastName = "Pan" },
        new Person() { FirstName = "Tinker", LastName = "Bell" },
        new Person() { FirstName = "James", LastName = "Hook" },
        new Person() { FirstName = "Wendy", LastName = "Darling" },
    };

    var bindingSource = new BindingSource() { DataSource = people };

    comboBoxPeople.DataSource = bindingSource;
    textBoxFirstName.DataBindings.Add(nameof(TextBox.Text), bindingSource, nameof(Person.FirstName), false, DataSourceUpdateMode.OnPropertyChanged);
    textBoxLastName.DataBindings.Add(nameof(TextBox.Text), bindingSource, nameof(Person.LastName), false, DataSourceUpdateMode.OnPropertyChanged);
}

现在你有一个装满人的组合框。选择另一个人后，文本框将自动填充适当的数据。