ASP.NET MVC 从IHttp到页面输出的实例代码

mvchandler : ihttphandler
void ihttphandler.processrequest(httpcontext httpcontext)
{
    this.processrequest(httpcontext);
}

protected virtual void processrequest(httpcontext httpcontext)
{
    httpcontextbase base2 = new httpcontextwrapper(httpcontext);
    this.processrequest(base2);
}

protected internal virtual void processrequest(httpcontextbase httpcontext)
{
    icontroller controller;
    icontrollerfactory factory;
    this.processrequestinit(httpcontext, out controller, out factory);
    try
    {
        controller.execute(this.requestcontext);
    }
    finally
    {
        factory.releasecontroller(controller);
    }
}       

controller : controllerbase : icontroller
void icontroller.execute(requestcontext requestcontext)  //------>controller
{
    this.execute(requestcontext);
}

protected virtual void execute(requestcontext requestcontext)   //------>controllerbase
{
    if (requestcontext == null)
    {
        throw new argumentnullexception("requestcontext");
    }
    if (requestcontext.httpcontext == null)
    {
        throw new argumentexception(mvcresources.controllerbase_cannotexecutewithnullhttpcontext, "requestcontext");
    }
    this.verifyexecutecalledonce();
    this.initialize(requestcontext);
    using (scopestorage.createtransientscope())
    {
        this.executecore();
    }
}

protected override void executecore()   //------>controller
{
    this.possiblyloadtempdata();
    try
    {
        string requiredstring = this.routedata.getrequiredstring("action");
        if (!this.actioninvoker.invokeaction(base.controllercontext, requiredstring))   //public iactioninvoker actioninvoker { get; set; }
        {
            this.handleunknownaction(requiredstring);
        }
    }
    finally
    {
        this.possiblysavetempdata();
    }
}

controlleractioninvoker : iactioninvoker
public virtual bool invokeaction(controllercontext controllercontext, string actionname)
{
    if (controllercontext == null)
    {
        throw new argumentnullexception("controllercontext");
    }
    if (string.isnullorempty(actionname))
    {
        throw new argumentexception(mvcresources.common_nullorempty, "actionname");
    }
    controllerdescriptor controllerdescriptor = this.getcontrollerdescriptor(controllercontext);
    actiondescriptor actiondescriptor = this.findaction(controllercontext, controllerdescriptor, actionname);
    if (actiondescriptor == null)
    {
        return false;
    }
    filterinfo filters = this.getfilters(controllercontext, actiondescriptor);
    try
    {
        authorizationcontext context = this.invokeauthorizationfilters(controllercontext, filters.authorizationfilters, actiondescriptor);
        if (context.result != null)
        {
            this.invokeactionresult(controllercontext, context.result);
        }
        else
        {
            if (controllercontext.controller.validaterequest)
            {
                validaterequest(controllercontext);
            }
            idictionary<string, object> parametervalues = this.getparametervalues(controllercontext, actiondescriptor);
            actionexecutedcontext context2 = this.invokeactionmethodwithfilters(controllercontext, filters.actionfilters, actiondescriptor, parametervalues);
            this.invokeactionresultwithfilters(controllercontext, filters.resultfilters, context2.result);
        }
    }
    catch (threadabortexception)
    {
        throw;
    }
    catch (exception exception)
    {
        exceptioncontext context3 = this.invokeexceptionfilters(controllercontext, filters.exceptionfilters, exception);
        if (!context3.exceptionhandled)
        {
            throw;
        }
        this.invokeactionresult(controllercontext, context3.result);
    }
    return true;
}

protected virtual void invokeactionresult(controllercontext controllercontext, actionresult actionresult)
{
    actionresult.executeresult(controllercontext);
}

actionresult
public override void executeresult(controllercontext context)
{
    if (context == null)
    {
        throw new argumentnullexception("context");
    }
    if (string.isnullorempty(this.viewname))
    {
        this.viewname = context.routedata.getrequiredstring("action");
    }
    viewengineresult result = null;
    if (this.view == null)
    {
        result = this.findview(context);   //viewengineresult
        this.view = result.view;    //iview接口   
    }
    textwriter output = context.httpcontext.response.output;
    viewcontext viewcontext = new viewcontext(context, this.view, this.viewdata, this.tempdata, output);
    this.view.render(viewcontext, output);
    if (result != null)
    {
        result.viewengine.releaseview(context, this.view);
    }
}