我已经创建了一个自定义的WPF用户控件,该控件旨在供第三方使用。我的控件有一个可释放的私有成员,我希望确保一旦包含的窗口/应用程序关闭,它的dispose方法就会被调用。但是,UserControl不是一次性的。
我尝试实现IDisposable接口并订阅Unloaded事件,但在主机应用程序关闭时都没有调用。MSDN表示可能根本不会引发卸载事件。它也可能被触发不止一次,即当用户更改主题时。
如果可能的话,我不想依赖我的控件的使用者记得调用特定的Dispose方法。
public partial class MyWpfControl : UserControl
{
SomeDisposableObject x;
// where does this code go?
void Somewhere()
{
if (x != null)
{
x.Dispose();
x = null;
}
}
}
到目前为止,我找到的唯一解决方案是订阅Dispatcher的ShutdownStarted事件。这是一个合理的方法吗?
this.Dispatcher.ShutdownStarted += Dispatcher_ShutdownStarted;
发布于 2009-02-02 10:24:34
有趣的博客文章在这里:Dispose of a WPF UserControl (ish)
它提到了订阅Dispatcher.ShutdownStarted来处理您的资源。
发布于 2009-07-07 22:31:22
你必须小心使用析构函数。这将在GC终结器线程上调用。在某些情况下,您释放的资源可能不喜欢在与创建它们的线程不同的线程上释放。
发布于 2014-10-22 17:07:04
我使用下面的交互行为向WPF UserControls提供一个卸载事件。您可以将行为包含在UserControls XAML中。因此,您无需将逻辑放在每个UserControl中,即可拥有该功能。
XAML声明:
xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
<i:Interaction.Behaviors>
<behaviors:UserControlSupportsUnloadingEventBehavior UserControlClosing="UserControlClosingHandler" />
</i:Interaction.Behaviors>
CodeBehind处理程序:
private void UserControlClosingHandler(object sender, EventArgs e)
{
// to unloading stuff here
}
行为代码:
/// <summary>
/// This behavior raises an event when the containing window of a <see cref="UserControl"/> is closing.
/// </summary>
public class UserControlSupportsUnloadingEventBehavior : System.Windows.Interactivity.Behavior<UserControl>
{
protected override void OnAttached()
{
AssociatedObject.Loaded += UserControlLoadedHandler;
}
protected override void OnDetaching()
{
AssociatedObject.Loaded -= UserControlLoadedHandler;
var window = Window.GetWindow(AssociatedObject);
if (window != null)
window.Closing -= WindowClosingHandler;
}
/// <summary>
/// Registers to the containing windows Closing event when the UserControl is loaded.
/// </summary>
private void UserControlLoadedHandler(object sender, RoutedEventArgs e)
{
var window = Window.GetWindow(AssociatedObject);
if (window == null)
throw new Exception(
"The UserControl {0} is not contained within a Window. The UserControlSupportsUnloadingEventBehavior cannot be used."
.FormatWith(AssociatedObject.GetType().Name));
window.Closing += WindowClosingHandler;
}
/// <summary>
/// The containing window is closing, raise the UserControlClosing event.
/// </summary>
private void WindowClosingHandler(object sender, CancelEventArgs e)
{
OnUserControlClosing();
}
/// <summary>
/// This event will be raised when the containing window of the associated <see cref="UserControl"/> is closing.
/// </summary>
public event EventHandler UserControlClosing;
protected virtual void OnUserControlClosing()
{
var handler = UserControlClosing;
if (handler != null)
handler(this, EventArgs.Empty);
}
}
https://stackoverflow.com/questions/502761
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