1
我有一個綁定到List<string>
的ComboBox。當List改變時,即使PropertyChanged被引發,ComboBox也不會。在調試時,我發現List屬性甚至被讀取。當ItemsSource更改時ComboBox不會更新
可以使用下面的代碼被複制的錯誤:
XAML
<Window x:Class="ComboBoxTest.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="90" Width="400">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<ComboBox ItemsSource="{Binding Source, Mode=OneWay}"/>
<Button Grid.Column="1" Content="add string" Command="{Binding}" CommandParameter="Add"/>
</Grid>
</Window>
代碼爲什麼不是組合框upda背後
using System.Windows;
namespace ComboBoxTest
{
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
DataContext = new ViewModel();
}
}
}
視圖模型
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Windows.Input;
namespace ComboBoxTest
{
class ViewModel : INotifyPropertyChanged, ICommand
{
public ViewModel()
{
Source = new List<string>();
Source.Add("Test1");
Source.Add("Test2");
Source.Add("Test3");
}
private List<string> _Source;
public List<string> Source
{
get { return _Source; }
set
{
_Source = value;
OnPropertyChanged("Source");
}
}
private void OnPropertyChanged(string property)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(property));
}
}
public event PropertyChangedEventHandler PropertyChanged;
public bool CanExecute(object parameter)
{
return true;
}
public event System.EventHandler CanExecuteChanged;
public void Execute(object parameter)
{
if ((string)parameter == "Add")
{
Source.Add("New string");
OnPropertyChanged("Source");
}
}
}
}
婷?
這裏重要的是它實現了'INotifyCollectionChanged',而不是'INotifyPropertyChanged'。 –
我剛看到它實現了兩個,但謝謝你的提示。我會糾正它。 – Breeze