我有一个要绑定到控件的自定义对象。在那个自定义对象上，我实现了 INotifyPropertyChanged 接口。我已成功绑定到我的对象和该对象上的属性。
我不知道如何从那里去。我已经为此工作了 2 天，但仍然无法正常工作。
我的假设是，当我更改绑定到控件的属性时，该属性中设置的值将显示在控件中。但是，无论我如何更改属性，UI 都不会更新到超出其初始值。
我以这种方式实现了 INotifyPropertyChanged： A base class which implements INotifyPropertyChanged
所以我的基类是这样的：
[Serializable]
public abstract class BindableObject : INotifyPropertyChanged
{
#region Data
private static readonly Dictionary<string, PropertyChangedEventArgs> eventArgCache;
private const string ERROR_MSG = "{0} is not a public property of {1}";
#endregion // Data
#region Constructors
static BindableObject()
{
eventArgCache = new Dictionary<string, PropertyChangedEventArgs>();
}
protected BindableObject()
{
}
#endregion // Constructors
#region Public Members
/// <summary>
/// Raised when a public property of this object is set.
/// </summary>
[field: NonSerialized]
public event PropertyChangedEventHandler PropertyChanged;
/// <summary>
/// Returns an instance of PropertyChangedEventArgs for
/// the specified property name.
/// </summary>
/// <param name="propertyName">
/// The name of the property to create event args for.
/// </param>
public static PropertyChangedEventArgs
GetPropertyChangedEventArgs(string propertyName)
{
if (String.IsNullOrEmpty(propertyName))
throw new ArgumentException(
"propertyName cannot be null or empty.");
PropertyChangedEventArgs args;
// Get the event args from the cache, creating them
// and adding to the cache if necessary.
lock (typeof(BindableObject))
{
bool isCached = eventArgCache.ContainsKey(propertyName);
if (!isCached)
{
eventArgCache.Add(
propertyName,
new PropertyChangedEventArgs(propertyName));
}
args = eventArgCache[propertyName];
}
return args;
}
#endregion // Public Members
#region Protected Members
/// <summary>
/// Derived classes can override this method to
/// execute logic after a property is set. The
/// base implementation does nothing.
/// </summary>
/// <param name="propertyName">
/// The property which was changed.
/// </param>
protected virtual void AfterPropertyChanged(string propertyName)
{
}
/// <summary>
/// Attempts to raise the PropertyChanged event, and
/// invokes the virtual AfterPropertyChanged method,
/// regardless of whether the event was raised or not.
/// </summary>
/// <param name="propertyName">
/// The property which was changed.
/// </param>
protected void RaisePropertyChanged(string propertyName)
{
this.VerifyProperty(propertyName);
PropertyChangedEventHandler handler = this.PropertyChanged;
if (handler != null)
{
// Get the cached event args.
PropertyChangedEventArgs args =
GetPropertyChangedEventArgs(propertyName);
// Raise the PropertyChanged event.
handler(this, args);
}
this.AfterPropertyChanged(propertyName);
}
#endregion // Protected Members
#region Private Helpers
[Conditional("DEBUG")]
private void VerifyProperty(string propertyName)
{
Type type = this.GetType();
// Look for a public property with the specified name.
PropertyInfo propInfo = type.GetProperty(propertyName);
if (propInfo == null)
{
// The property could not be found,
// so alert the developer of the problem.
string msg = string.Format(
ERROR_MSG,
propertyName,
type.FullName);
Debug.Fail(msg);
}
}
#endregion // Private Helpers
}
我从上面的那个类继承，在我的派生类中，我在我的财产上这样做：
public virtual string Name
{
get
{
return m_strName;
}
set
{
m_strName = value;
RaisePropertyChanged("Name");
}
}
我的 XAML 看起来像这样（缩写版）：
<Window x:Class="PSSPECApplication.Windows.Project"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:System="clr-namespace:System;assembly=mscorlib"
DataContext="{Binding SizingProject, RelativeSource={RelativeSource Self}}">
<StackPanel VerticalAlignment="Center">
<TextBox Name="txtProjectName" Text="{Binding Name}" />
</StackPanel>
您可以看到窗口的数据上下文是一个名为 SizingProject 的属性。SizingProject 属于派生类型（派生自 BindableObject），其中包含 Name 属性并引发 PropertyChanged 事件处理程序。
在我的窗口的构造函数中，我填充了 SizingProject 并设置了它的 Name 属性。
为了测试这一点，我在窗口上还有一个按钮，它触发一个事件，将 Name 属性设置为不同于原来的值。但是，当更改 name 属性时，什么也没有发生。我已经追溯到 BindableObject 并且 PropertyChanged 事件始终设置为 null，因此没有设置和运行任何处理程序。为什么是这样？
我想通过实现 INotifyPropertyChanged 并在绑定中使用该类型强制 WPF 自动设置该事件处理程序，然后发生正确的行为？对我来说，我从未见过这种行为。
我弄清楚了这个问题。我需要做的是为我的属性 SizingProject 创建一个 DependencyProperty。在我这样做之后，一切正常。
public static readonly DependencyProperty SizingProjectProperty =
DependencyProperty.Register("SizingProject", typeof(Sizing.Project), typeof(Project), new UIPropertyMetadata());
public Sizing.Project SizingProject
{
get
{
return (Sizing.Project)GetValue(Project.SizingProjectProperty);
}
set
{
SetValue(Project.SizingProjectProperty, value);
}
}