我已经实现了我自己的模型视图演示者模式的副本(在Web客户端软件工厂的静脉中),所以我可以利用我自己的DI框架而不是绑定到WCSF的ObjectBuilder,我遇到了很多问题.我想出了几个方法来做到这一点,但没有一个特别让我开心.我想知道是否有其他人有其他想法.
解决方案#1a
使用HttpModule拦截context.PreRequestHandlerExecute来调用ObjectFactory.BuildUp(HttpContext.Current.Handler)
public partial class _Default : Page,IEmployeeView
{
private EmployeePresenter _presenter;
private EmployeePresenter Presenter
{
set
{
_presenter = value;
_presenter.View = this;
}
}
}
解决方案#1b
在页面加载中调用buildup而不是使用HttpModule
public partial class _Default : Page,IEmployeeView
{
private EmployeePresenter _presenter;
private EmployeePresenter Presenter
{
set
{
_presenter = value;
_presenter.View = this;
}
}
protected void Page_Load(object sender,EventArgs e)
{
ObjectFactory.BuildUp(this);
}
}
解决方案#1c
如果需要,通过Property访问presenter允许Getter to BuildUp.
public partial class _Default : Page,IEmployeeView
{
private EmployeePresenter _presenter;
public EmployeePresenter Presenter
{
get
{
if (_presenter == null)
{
ObjectFactory.BuildUp(this);
}
return _presenter;
}
set
{
_presenter = value;
_presenter.View = this;
}
}
}
解决方案#2
public partial class _Default : Page,IEmployeeView
{
private EmployeePresenter _presenter;
private EmployeePresenter Presenter
{
get
{
if (_presenter == null)
{
_presenter = ObjectFactory.GetInstance<EmployeePresenter>();
_presenter.View = this;
}
return _presenter;
}
}
}
解决方案#2b
public partial class _Default : Page,IEmployeeView
{
private EmployeePresenter _presenter;
private EmployeePresenter Presenter
{
get
{
if (_presenter == null)
{
Presenter = ObjectFactory.GetInstance<EmployeePresenter>();
}
return _presenter;
}
set
{
_presenter = value;
_presenter.View = this;
}
}
}
解决方法
我使用解决方案#1b,并为所有页面创建一个
layer supertype,以便更多地干掉演示者初始化.像这样：
页码：
public partial class _Default : AbstractPage,IEmployeeView
{
private EmployeePresenter presenter;
private EmployeePresenter Presenter
{
set
{
presenter = value;
presenter.View = this;
}
}
protected override void Do_Load(object sender,EventArgs args)
{
//do "on load" stuff
}
}
public abstract class AbstractPage : Page
{
protected void Page_Load(object sender,EventArgs e)
{
ObjectFactory.BuildUp(this);
this.Do_Load(sender,e);
//template method,to enable subclasses to mimic "Page_load" event
}
//Default Implementation (do nothing)
protected virtual void Do_Load(object sender,EventArgs e){}
}
使用此解决方案,您只能在一个类中进行演示者初始化(由ObjectFactory创建),如果您以后需要对其进行修改,则可以轻松完成.
编辑：
Do_Load应该是抽象的还是虚拟的？
Template Method最初声明该方法应该是Abstract,以强制子类实现它,遵守超类契约. (参见维基百科“垄断”的例子<“游戏”). 另一方面,在这种特殊情况下,我们不希望强制用户类重新定义我们的方法,但给它机会这样做.如果你声明它是抽象的,许多类将被迫重新定义方法只是为了让它为空(这显然是代码味道).所以我们提供合理的默认值(什么都不做)并使方法成为虚拟的.
