我试图做一些很基本的在这里,这是我不会期望给我这么多的问题。我有一个公共的财产我叫ITEMLIST主窗口类是类型名单,其中,串>
。我添加到整个项目的生命这份名单中,并希望ListBox控件我有我的形式,当我添加新的项目到ITEMLIST属性自动更新。
I'm trying to do something very basic here, something I wouldn't have expected to give me this many problems. I have a public property on my main Window class called ItemList which is of type List<string>
. I add to this list throughout the life of the program, and would like the ListBox control I have on my form to automatically update when I add new items to the ItemList property.
到目前为止,我有以下的XAML:
So far, I have the following XAML:
<Window x:Class="ElserBackupGUI.Main"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Backup Profile Editor [New Profile]" Height="480" Width="640">
<DockPanel>
<Menu DockPanel.Dock="Top">
<MenuItem Header="File">
<MenuItem Header="Open"/>
</MenuItem>
</Menu>
<StackPanel Orientation="Vertical" DockPanel.Dock="Top" Margin="10 10 10 3">
<TextBlock>Items to backup:</TextBlock>
</StackPanel>
<DockPanel DockPanel.Dock="Bottom" Margin="10 0 10 10">
<StackPanel Orientation="Horizontal">
<Button Name="AddDirectoryButton" Height="22.725" Width="120" Margin="0 0 6 0" Click="AddDirectoryButton_Click">Add Directory...</Button>
<Button Name="AddFileButton" Height="22.725" Width="90" Margin="0 0 6 0" Click="AddFileButton_Click">Add File...</Button>
<Button Name="RemoveDirectoriesButton" Height="22.725" Width="75.447" Margin="0 0 6 0">Remove</Button>
</StackPanel>
</DockPanel>
<ListBox Name="SelectedItems" Margin="10 0 10 10" ItemsSource="{Binding Path=ItemList}"/>
</DockPanel>
</Window>
相关code-背后code是这样的:
The relevant code-behind code looks like:
public partial class Main : Window
{
private string _lastFolder = string.Empty;
private ObservableCollection<string> _itemList = new ObservableCollection<string>();
public ObservableCollection<string> ItemList {
get { return _itemList ?? (_itemList = new ObservableCollection<string>()); }
set { _itemList = value; }
}
public Main()
{
InitializeComponent();
ItemList.Add("test item");
DataContext = this;
}
private void AddDirectoryButton_Click(object sender, RoutedEventArgs e)
{
FolderBrowserDialog dialog = new FolderBrowserDialog();
if (!string.IsNullOrEmpty(_lastFolder))
dialog.SelectedPath = _lastFolder;
if (dialog.ShowDialog() == System.Windows.Forms.DialogResult.OK)
{
_lastFolder = dialog.SelectedPath;
ItemList.Add(dialog.SelectedPath);
}
}
private void AddFileButton_Click(object sender, RoutedEventArgs e)
{
OpenFileDialog dialog = new OpenFileDialog();
if (!string.IsNullOrEmpty(_lastFolder))
dialog.InitialDirectory = _lastFolder;
if (dialog.ShowDialog() == System.Windows.Forms.DialogResult.OK)
{
_lastFolder = System.IO.Path.GetDirectoryName(dialog.FileName);
SelectedItems.ItemsSource = null;
ItemList.Add(dialog.FileName);
}
}
}
我是比较新的WPF和大多数的教程似乎过于复杂,这样一个简单的问题。我似乎无法得到任何地方在这里 - 我缺少什么
I'm relatively new to WPF and most of the tutorials seem overly complicated for such a simple problem. I can't seem to get anywhere here - what am I missing?
推荐答案
您应该使用 的BindingList&LT; T&GT;
或ObservableCollection<T>而不是名单,其中,T&GT;
的问题在于,用于结合工作,你想要的方式,它需要执行INotifyCollectionChanged或IBindingList. 名单,其中,T&GT;
不支持此
The problem is that, for binding to work the way you want, it needs to implement INotifyCollectionChanged
or IBindingList
. List<T>
does not support this.
编辑:
审核更改后,仍有一个问题。
After reviewing your changes, there is still one problem.
在AddFileButton_Click事件处理程序,删除以下行:
In the AddFileButton_Click event handler, remove the following line:
SelectedItems.ItemsSource = null;
有明确移除你的绑定,并造成列表框中清除。如果删除,你的code应该原样。
It is explicitly removing your binding, and causing the list box to clear. If you remove that, your code should work as-is.
不过,我建议改变你的集合定义和构造更多的东西,如:
However, I do recommend changing your collection definition and constructor to something more like:
// No need for the null checking every time, or public setter. They just cause issues
public ObservableCollection<string> ItemList
{
get;
private set;
}
// Add construction here, now that we're using an auto-prop
public Main()
{
this.ItemList = new ObservableCollection<string>();
InitializeComponent();
ItemList.Add("test item");
DataContext = this;
}
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