使用 .NET 3.5 项目对此进行测试,绑定似乎对我有用。您是否在 ViewModel 上实现了 INotifyPropertyChanged 并在设置 ShowMeoDataOnly 时适当地使用它?您没有发布所有代码,因此很难判断 ViewModel 在做什么。
这就是我所做的工作。当我运行应用程序时,该按钮被选中。那是因为ViewModelBase
实现INotifyPropertyChanged
,我base.OnPropertyChanged("ShowMeoDataOnly")
在设置属性时会这样做。
主窗口.xaml
<Window x:Class="ToggleButtonIsCheckedBinding.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:ToggleButtonIsCheckedBinding"
Title="MainWindow" Height="350" Width="525">
<Window.DataContext>
<local:MainWindowViewModel />
</Window.DataContext>
<Grid>
<ToggleButton IsChecked="{Binding ShowMeoDataOnly, Mode=TwoWay}">
Show Meo Data Only
</ToggleButton>
</Grid>
</Window>
MainWindowViewModel.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace ToggleButtonIsCheckedBinding
{
class MainWindowViewModel : ViewModelBase
{
bool _showMeoDataOnly;
public bool ShowMeoDataOnly {
get
{
return _showMeoDataOnly;
}
set
{
_showMeoDataOnly = value;
base.OnPropertyChanged("ShowMeoDataOnly");
}
}
public MainWindowViewModel()
{
ShowMeoDataOnly = true;
}
}
}
ViewModelBase.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;
using System.ComponentModel;
namespace ToggleButtonIsCheckedBinding
{
/// <summary>
/// Base class for all ViewModel classes in the application.
/// It provides support for property change notifications
/// and has a DisplayName property. This class is abstract.
/// </summary>
public abstract class ViewModelBase : INotifyPropertyChanged, IDisposable
{
#region Constructor
protected ViewModelBase()
{
}
#endregion // Constructor
#region DisplayName
/// <summary>
/// Returns the user-friendly name of this object.
/// Child classes can set this property to a new value,
/// or override it to determine the value on-demand.
/// </summary>
public virtual string DisplayName { get; protected set; }
#endregion // DisplayName
#region Debugging Aides
/// <summary>
/// Warns the developer if this object does not have
/// a public property with the specified name. This
/// method does not exist in a Release build.
/// </summary>
[Conditional("DEBUG")]
[DebuggerStepThrough]
public void VerifyPropertyName(string propertyName)
{
// Verify that the property name matches a real,
// public, instance property on this object.
if (TypeDescriptor.GetProperties(this)[propertyName] == null)
{
string msg = "Invalid property name: " + propertyName;
if (this.ThrowOnInvalidPropertyName)
throw new Exception(msg);
else
Debug.Fail(msg);
}
}
/// <summary>
/// Returns whether an exception is thrown, or if a Debug.Fail() is used
/// when an invalid property name is passed to the VerifyPropertyName method.
/// The default value is false, but subclasses used by unit tests might
/// override this property's getter to return true.
/// </summary>
protected virtual bool ThrowOnInvalidPropertyName { get; private set; }
#endregion // Debugging Aides
#region INotifyPropertyChanged Members
/// <summary>
/// Raised when a property on this object has a new value.
/// </summary>
public event PropertyChangedEventHandler PropertyChanged;
/// <summary>
/// Raises this object's PropertyChanged event.
/// </summary>
/// <param name="propertyName">The property that has a new value.</param>
protected virtual void OnPropertyChanged(string propertyName)
{
this.VerifyPropertyName(propertyName);
PropertyChangedEventHandler handler = this.PropertyChanged;
if (handler != null)
{
var e = new PropertyChangedEventArgs(propertyName);
handler(this, e);
}
}
#endregion // INotifyPropertyChanged Members
#region IDisposable Members
/// <summary>
/// Invoked when this object is being removed from the application
/// and will be subject to garbage collection.
/// </summary>
public void Dispose()
{
this.OnDispose();
}
/// <summary>
/// Child classes can override this method to perform
/// clean-up logic, such as removing event handlers.
/// </summary>
protected virtual void OnDispose()
{
}
#if DEBUG
/// <summary>
/// Useful for ensuring that ViewModel objects are properly garbage collected.
/// </summary>
~ViewModelBase()
{
string msg = string.Format("{0} ({1}) ({2}) Finalized", this.GetType().Name, this.DisplayName, this.GetHashCode());
System.Diagnostics.Debug.WriteLine(msg);
}
#endif
#endregion // IDisposable Members
}
}
(注意:ViewModelBase 是从这个项目中提取的:http: //msdn.microsoft.com/en-us/magazine/dd419663.aspx)