【发布时间】：2011-06-05 17:23:00
【问题描述】：
我在 WFP Caliburn.Micro 框架中使用。 我需要 Document 属性的可绑定richTextbox。我发现了很多方法如何绑定richTextBox。
但我有一个问题。从父窗口我打开子窗口。子窗口由可绑定的richTextBox 用户控件组成。
在我关闭子窗口并使用带有 bindabelrichTextBox 控件的内存分析器视图类后，视图模型类仍然挂在内存中。 -> 这会导致内存泄漏。
如果我使用 .NET Framework 中的 richTextBox 或 Extended WPF Toolkit 中的richTextBox，则不会导致此内存泄漏问题。
我无法识别可绑定的richTextBox 类中的问题。
这是可绑定的richTextBox的一个类：
基类可以来自 .NET 或扩展工具包。
/// <summary>
/// Represents a bindable rich editing control which operates on System.Windows.Documents.FlowDocument
/// objects.
/// </summary>
public class BindableRichTextBox : RichTextBox
{
/// <summary>
/// Identifies the <see cref="Document"/> dependency property.
/// </summary>
public static readonly DependencyProperty DocumentProperty = DependencyProperty.Register("Document",
typeof(FlowDocument), typeof(BindableRichTextBox));
/// <summary>
/// Initializes a new instance of the <see cref="BindableRichTextBox"/> class.
/// </summary>
public BindableRichTextBox()
: base()
{
}
/// <summary>
/// Initializes a new instance of the <see cref="BindableRichTextBox"/> class.
/// </summary>
/// <param title="document">A <see cref="T:System.Windows.Documents.FlowDocument"></see> to be added as the initial contents of the new <see cref="T:System.Windows.Controls.BindableRichTextBox"></see>.</param>
public BindableRichTextBox(FlowDocument document)
: base(document)
{
}
/// <summary>
/// Raises the <see cref="E:System.Windows.FrameworkElement.Initialized"></see> event. This method is invoked whenever <see cref="P:System.Windows.FrameworkElement.IsInitialized"></see> is set to true internally.
/// </summary>
/// <param title="e">The <see cref="T:System.Windows.RoutedEventArgs"></see> that contains the event data.</param>
protected override void OnInitialized(EventArgs e)
{
// Hook up to get notified when DocumentProperty changes.
DependencyPropertyDescriptor descriptor = DependencyPropertyDescriptor.FromProperty(DocumentProperty, typeof(BindableRichTextBox));
descriptor.AddValueChanged(this, delegate
{
// If the underlying value of the dependency property changes,
// update the underlying document, also.
base.Document = (FlowDocument)GetValue(DocumentProperty);
});
// By default, we support updates to the source when focus is lost (or, if the LostFocus
// trigger is specified explicity. We don't support the PropertyChanged trigger right now.
this.LostFocus += new RoutedEventHandler(BindableRichTextBox_LostFocus);
base.OnInitialized(e);
}
/// <summary>
/// Handles the LostFocus event of the BindableRichTextBox control.
/// </summary>
/// <param title="sender">The source of the event.</param>
/// <param title="e">The <see cref="System.Windows.RoutedEventArgs"/> instance containing the event data.</param>
void BindableRichTextBox_LostFocus(object sender, RoutedEventArgs e)
{
// If we have a binding that is set for LostFocus or Default (which we are specifying as default)
// then update the source.
Binding binding = BindingOperations.GetBinding(this, DocumentProperty);
if (binding.UpdateSourceTrigger == UpdateSourceTrigger.Default ||
binding.UpdateSourceTrigger == UpdateSourceTrigger.LostFocus)
{
BindingOperations.GetBindingExpression(this, DocumentProperty).UpdateSource();
}
}
/// <summary>
/// Gets or sets the <see cref="T:System.Windows.Documents.FlowDocument"></see> that represents the contents of the <see cref="T:System.Windows.Controls.BindableRichTextBox"></see>.
/// </summary>
/// <value></value>
/// <returns>A <see cref="T:System.Windows.Documents.FlowDocument"></see> object that represents the contents of the <see cref="T:System.Windows.Controls.BindableRichTextBox"></see>.By default, this property is set to an empty <see cref="T:System.Windows.Documents.FlowDocument"></see>. Specifically, the empty <see cref="T:System.Windows.Documents.FlowDocument"></see> contains a single <see cref="T:System.Windows.Documents.Paragraph"></see>, which contains a single <see cref="T:System.Windows.Documents.Run"></see> which contains no text.</returns>
/// <exception cref="T:System.ArgumentException">Raised if an attempt is made to set this property to a <see cref="T:System.Windows.Documents.FlowDocument"></see> that represents the contents of another <see cref="T:System.Windows.Controls.RichTextBox"></see>.</exception>
/// <exception cref="T:System.ArgumentNullException">Raised if an attempt is made to set this property to null.</exception>
/// <exception cref="T:System.InvalidOperationException">Raised if this property is set while a change block has been activated.</exception>
public new FlowDocument Document
{
get { return (FlowDocument)GetValue(DocumentProperty); }
set { SetValue(DocumentProperty, value); }
}
}
感谢您的帮助和建议。
快速示例：
带有 .NET richTextBox 的子窗口
<Window x:Class="WpfApplication2.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Window1" Height="300" Width="300">
<Grid>
<RichTextBox Background="Green"
VerticalScrollBarVisibility="Auto"
HorizontalScrollBarVisibility="Auto"
FontSize="13"
Margin="4,4,4,4"
Grid.Row="0"/>
</Grid>
</Window>
我从父窗口打开的这个窗口：
var w = new Window1();
w.Show();
然后关闭这个窗口，用内存分析器检查内存不存在window1-richTextBox的任何对象。没关系。
但后来我尝试了可绑定的richTextBox：
子窗口 2：
<Window x:Class="WpfApplication2.Window2"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:Controls="clr-namespace:WpfApplication2.Controls"
Title="Window2" Height="300" Width="300">
<Grid>
<Controls:BindableRichTextBox Background="Red"
VerticalScrollBarVisibility="Auto"
HorizontalScrollBarVisibility="Auto"
FontSize="13"
Margin="4,4,4,4"
Grid.Row="0" />
</Grid>
</Window>
打开子窗口2，关闭这个子窗口，在内存中这个子窗口的对象还活着，也可以绑定richTextBox对象。
【问题讨论】：
标签： wpf binding memory-leaks richtextbox flowdocument