Caliburn笔记-Presenter的管理(wpf框架)

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我是靠谱客的博主粗犷彩虹，最近开发中收集的这篇文章主要介绍Caliburn笔记-Presenter的管理(wpf框架)，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

回头来看caliburn是如何初始化程序界面

CaliburnApplication

CaliburnApplication继承自WPF的Application类,其初始化了caliburn的接口,同时提供了一个窗口管理的接口IWindowManager,与prism框架不同这个shell是非强制性的

一.初始化

///<summary>
/// Raises the <see cref="E:System.Windows.Application.Startup"/> event.
/// </summary>
/// <param name="e">A <see cref="T:System.Windows.StartupEventArgs"/> that contains the event data.</param>
protected override void OnStartup(StartupEventArgs e)
{
base.OnStartup(e);
var rootModel = CreateRootModel();
if (rootModel == null) return;
ShowMainWindow(rootModel);
}
/// <summary>
/// Creates the root application model.
/// </summary>
/// <returns></returns>
protected virtual object CreateRootModel()
{
return null;
}
/// <summary>
/// Shows the main window based on the provided model.
/// </summary>
/// <param name="rootModel">The root model.</param>
protected virtual void ShowMainWindow(object rootModel)
{
Container.GetInstance<IWindowManager>()
.Show(rootModel, null, ExecuteShutdownModel);
}
/// <summary>
/// Executes the shutdown model.
/// </summary>
/// <param name="subordinate">The subordinate.</param>
/// <param name="completed">The completed.</param>
protected virtual void ExecuteShutdownModel(ISubordinate subordinate, Action completed)
{
completed();

根据以上代码可得知,继承的类需要重写CreateRootModel和ExecuteShutdownModel方法.具体由IWindowManager负责处理

万事具备后IWindowManager负责初始化

初始化时容器可为Window也可以为UserControl，若是UserControl则会自动创建一个Window作为容器，但不建议这么做

/// <summary>
/// Ensures the that the view is a window or provides one.
/// </summary>
/// <param name="model">The model.</param>
/// <param name="view">The view.</param>
/// <returns></returns>
protected virtual Window EnsureWindow(object model, object view)
{
var window = view as Window;
if(window == null)
{
window = new Window
{
Content = view,
SizeToContent = SizeToContent.WidthAndHeight
};
if(Application.Current != null
&& Application.Current.MainWindow != null)
{
window.Owner = Application.Current.MainWindow;
}
var presenter = model as IPresenter;
if(presenter != null)
window.Title = presenter.DisplayName;
}
else if (Application.Current != null
&& Application.Current.MainWindow != null)
{
if(Application.Current.MainWindow != window)
window.Owner = Application.Current.MainWindow;
}
return window;
}

初始化Presenter

/// <summary>
/// Shows a window for the specified model.
/// </summary>
/// <param name="rootModel">The root model.</param>
/// <param name="context">The context.</param>
/// <param name="handleShutdownModel">The handle shutdown model.</param>
public void Show(object rootModel, object context, Action<ISubordinate, Action> handleShutdownModel)
{
var window = CreateWindow(rootModel, context, handleShutdownModel);
window.Show();
}
/// <summary>
/// Creates the window.
/// </summary>
/// <param name="rootModel">The root model.</param>
/// <param name="context">The context.</param>
/// <param name="handleShutdownModel">The handle shutdown model.</param>
/// <returns></returns>
protected Window CreateWindow(object rootModel, object context, Action<ISubordinate, Action> handleShutdownModel)
{
var view = EnsureWindow(rootModel, _viewStrategy.GetView(rootModel, null, context));
_binder.Bind(rootModel, view, context);
var presenter = rootModel as IPresenter;
if (presenter != null)
{

presenter.Initialize();
presenter.Activate();
view.Closing += (s, e) => OnShutdownAttempted(presenter, view, handleShutdownModel, e);
view.Closed += delegate{
presenter.Deactivate();
presenter.Shutdown();
};
}
return view;
}

以上presenter的生命周期就比较明朗了.

IPresenterManager

IPresenterManager is an IPresenterHost that tracks a CurrentPresenter. Whenever the CurrentPresenter is changed, the old one is deactivated/shutdown and the new one is initialized/activated.

IPresenterManager可以将一个Presenter与另外一个Presenter关联起来,两者属于父子关系,即IPresenterNode的Parent属性(IPresenterHost),一下为重写的方法

#region override method
/// <summary>
/// Determines whether this instance can shutdown.
/// </summary>
/// <returns>
///
<c>true</c> if this instance can shutdown; otherwise, <c>false</c>.
/// </returns>
public override bool CanShutdown()
{
if(_currentPresenter != null)
return _currentPresenter.CanShutdown();
return true;
}
/// <summary>
/// Initializes this instance.
/// </summary>
public override void Initialize()
{
if(!IsInitialized)
{
OnInitialize();
if(_currentPresenter != null)
_currentPresenter.Initialize();
IsInitialized = true;
}
}
/// <summary>
/// Shuts down this instance.
/// </summary>
public override void Shutdown()
{
if(_currentPresenter != null)
_currentPresenter.Shutdown();
OnShutdown();
}
/// <summary>
/// Activates this instance.
/// </summary>
public override void Activate()
{
if(!IsActive)
{
OnActivate();
if(_currentPresenter != null)
_currentPresenter.Activate();
IsActive = true;
}
}
/// <summary>
/// Deactivates this instance.
/// </summary>
public override void Deactivate()
{
if(IsActive)
{
OnDeactivate();
if(_currentPresenter != null)
_currentPresenter.Deactivate();
IsActive = false;
}
}

在设置新的Presenter时，首先会释放之前的Presenter

/// <summary>
/// Shuts down the current presenter.
/// </summary>
/// <param name="completed">Called when the shutdown action is finished.</param>
public virtual void ShutdownCurrent(Action<bool> completed)
{
if(_currentPresenter == null)
{
completed(true);
return;
}
CanShutdownPresenter(
_currentPresenter,
isSuccess =>{
if(!isSuccess)
{
completed(false);
return;
}
_currentPresenter.Deactivate();
_currentPresenter.Shutdown();
var node = _currentPresenter as IPresenterNode;
if (node != null) node.Parent = null;
_currentPresenter = null;
if(!_changingThroughProperty)
NotifyOfPropertyChange("CurrentPresenter");
completed(true);
});
}

PresenterManager的Open方法会初始化关联的Presenter,并设置CurrentPresenter

/// <summary>
/// Opens the specified presenter.
/// </summary>
/// <param name="presenter">The presenter.</param>
/// <param name="completed">Called when the open action is finished.</param>
public virtual void Open(IPresenter presenter, Action<bool> completed)
{
if(presenter == null)
{
completed(false);
return;
}
Action successfulCompletion =
() =>{
var node = presenter as IPresenterNode;
if (node != null) node.Parent = this;
presenter.Initialize();
presenter.Activate();
_currentPresenter = presenter;
if(!_changingThroughProperty)
NotifyOfPropertyChange("CurrentPresenter");
completed(true);
};
if(_currentPresenter != null)
{
CanShutdownPresenter(
_currentPresenter,
isSuccess =>{
if(!isSuccess)
{
completed(false);
return;
}
_currentPresenter.Deactivate();
_currentPresenter.Shutdown();
var node = _currentPresenter as IPresenterNode;
if (node != null) node.Parent = null;
successfulCompletion();
});
}
else successfulCompletion();
}