public void Handle(IExecutionPipelineContext context)
{
//在执行之前首先判断是否可以执行
if (!this.CanHandle(context))
{
return;
}
//创建“Executing”事件参数
var executingArgs = new ExecutionPipelineExecutingEventArgs(context);
//激发“Executing”事件
this.OnExecuting(executingArgs);
if (executingArgs.Cancel)
{
return;
}
//执行过滤器的前半截
var filters = ExecutionUtility.InvokeFiltersExecuting(_filters, filter => filter.OnExecuting(context));
//执行当前处理请求
this.OnExecute(context);
//执行过滤器的后半截
ExecutionUtility.InvokeFiltersExecuted(filters, filter => filter.OnExecuted(context));
//激发“Executed”事件
this.OnExecuted(new ExecutionPipelineExecutedEventArgs(context));
}
protected virtual bool InvokePipeline(IExecutionPipelineContext context)
{
var pipeline = context.Pipeline;
if (pipeline == null)
{
return(false);
}
//计算当前管道的执行条件，如果管道的条件评估器不为空则使用管道的评估器进行验证，否则使用管道的处理程序的CanHandle方法进行验证
var enabled = pipeline.Predication != null?pipeline.Predication.Predicate(context) : pipeline.Handler.CanHandle(context);
if (!enabled)
{
return(false);
}
//激发“PipelineExecuting”事件
this.OnPipelineExecuting(new ExecutionPipelineExecutingEventArgs(context));
Stack <IExecutionFilter> stack = null;
//调用当前管道过滤器的前半截
if (pipeline.HasFilters)
{
stack = ExecutionUtility.InvokeFiltersExecuting(pipeline.Filters, filter => this.OnFilterExecuting(filter, context));
}
//激发“HandlerExecuting”事件
this.OnHandlerExecuting(new ExecutionPipelineExecutingEventArgs(context));
//调用管道处理器处理当前请求
var isHandled = this.InvokeHandler(context);
//设置是否处理成功的值到到上下文的扩展属性集中
context.ExtendedProperties["__IsHandled__"] = isHandled;
//激发“HandlerExecuted”事件
this.OnHandlerExecuted(new ExecutionPipelineExecutedEventArgs(context));
//调用后续管道集合
if (context.HasChildren)
{
context.Result = this.InvokePipelines(context.Children, p => this.CreatePipelineContext(context, p, context.Result));
}
//调用当前管道过滤器的后半截
if (stack != null && stack.Count > 0)
{
ExecutionUtility.InvokeFiltersExecuted(stack, filter => this.OnFilterExecuted(filter, context));
}
//激发“PipelineExecuted”事件
this.OnPipelineExecuted(new ExecutionPipelineExecutedEventArgs(context));
return(isHandled);
}
protected virtual object CombineResult(IEnumerable <IExecutionPipelineContext> contexts)
{
var combiner = this.Combiner;
if (combiner != null)
{
return(combiner.Combine(contexts));
}
else
{
return(ExecutionUtility.CombineResult(contexts));
}
}
protected ExecutionResult Execute(IExecutionContext context)
{
if (context == null)
{
throw new ArgumentNullException("context");
}
//创建“Executing”事件的调用参数
ExecutingEventArgs executingArgs = new ExecutingEventArgs(context);
//激发“Executing”事件
this.OnExecuting(executingArgs);
if (executingArgs.Cancel)
{
return(new ExecutionResult(context));
}
//通过选择器获取当前请求对应的管道集
var pipelines = this.SelectPipelines(context, _pipelines);
//如果当前执行的处理管道数为零则退出
if (pipelines == null || pipelines.Count() < 1)
{
return(null);
}
//调用执行器过滤器的前半截
var stack = ExecutionUtility.InvokeFiltersExecuting(context.Executor.Filters, filter => this.OnFilterExecuting(filter, context));
//执行管道集，并将其执行的最终结果保存到执行器上下文的Result属性中
context.Result = this.InvokePipelines(pipelines, p => this.CreatePipelineContext(context, p, context.Parameter));
//调用执行器过滤器的后半截
ExecutionUtility.InvokeFiltersExecuted(stack, filter => this.OnFilterExecuted(filter, context));
//激发“Executed”事件
this.OnExecuted(new ExecutedEventArgs(context));
return(new ExecutionResult(context));
}