裝訂組合框

Question

我做的一切都對嗎？

public List<string> combolist { get; set; } 

...

this.combolist = new List<string>(); 
MySqlCommand status_db = new MySqlCommand("select name_ru from request_status", conn); 
MySqlDataReader combodata = status_db.ExecuteReader(); 
    while (combodata.Read()) 
    { 
    combolist.Add(combodata.GetString(0)); 
    } 
    this.DataContext = this; 

在XAML：

<ComboBox ItemsSource="{Binding Path=combolist}"... 

但項目組合框是空的，什麼是錯的？

Answer 1

您應該使用ObservableCollection。實例化的ObservableCollection調用的InitializeComponent（）之前

Answer 2

這個工程：

usercontrol1.xaml

<Grid> 
    <ComboBox ItemsSource="{Binding Combolist}" /> 
</Grid> 

usercontrol1.xaml.cs

public partial class UserControl1 : UserControl 
{ 
    public ObservableCollection<string> Combolist { get; private set; } 

    public UserControl1() 
    { 
     this.Combolist = new ObservableCollection<string>();//just initialize once! 
     InitializeComponent(); 
     //if you wanna load new data, call .Clear() before 
     //this.Combolist.Clear(); 
     //MySqlCommand status_db = new MySqlCommand("select name_ru from request_status", conn); 
     //MySqlDataReader combodata = status_db.ExecuteReader(); 
     //while (combodata.Read()) 
     //{ 
     // Combolist.Add(combodata.GetString(0)); 
     //} 

     //test 
     this.Combolist.Add("qqqq"); 
     this.Combolist.Add("wwww"); 
     this.Combolist.Add("eeee"); 
     this.Combolist.Add("rrrr"); 

     this.DataContext = this; 
    } 
}