C# 接口方法上的CreateDelegate
我很难看出我在创建接口方法的委托时出错的地方 我的代码如下:C# 接口方法上的CreateDelegate,c#,delegates,C#,Delegates,我很难看出我在创建接口方法的委托时出错的地方 我的代码如下: private static Func<HtmlDocument, IObservable<IData>> FindScrapeMethod(ICrawlerStrategy crawler, string scrapeDelegate) { Func<HtmlDocument, IObservable<IData>> action; var fullDelegateNa
private static Func<HtmlDocument, IObservable<IData>> FindScrapeMethod(ICrawlerStrategy crawler, string scrapeDelegate)
{
Func<HtmlDocument, IObservable<IData>> action;
var fullDelegateName = String.Format("ICrawlerStrategy.{0}", scrapeDelegate);
if (!_delegateCache.TryGetValue(fullDelegateName, out action))
{
var method = typeof(ICrawlerStrategy).GetMethod(scrapeDelegate, BindingFlags.Public | BindingFlags.Instance );
action = (Func<HtmlDocument, IObservable<IData>>)
Delegate.CreateDelegate(typeof(Func<HtmlDocument, IObservable<IData>>), crawler, method);
_delegateCache.Add(fullDelegateName, action);
}
return action;
}
private static Func FindScrapeMethod(ICrawlerStrategy爬虫、字符串爬虫委托)
{
Func行动;
var fullDelegateName=String.Format(“ICrawlerStrategy.{0}”,scrapedegate);
if(!\u delegateCache.TryGetValue(fullDelegateName,out操作))
{
var method=typeof(ICrawlerStrategy).GetMethod(scrapedegate,BindingFlags.Public | BindingFlags.Instance);
动作=(Func)
CreateDelegate(typeof(Func),crawler,method);
_delegateCache.Add(fullDelegateName,action);
}
返回动作;
}
接口声明是
public interface ICrawlerStrategy
{
Func<HtmlDocument, IObservable<IData>> ExtractorAsync();
}
公共接口ICrawler策略
{
Func ExtractorAsync();
}
实现类如下所示
public class MyCrawler : ICrawlerStrategy
{
<snip>
Func<HtmlDocument, IObservable<IData>> ICrawlerStrategy.ExtractorAsync()
{
return (doc) => AsyncScraper(doc);
}
}
公共类MyCrawler:icrawler策略
{
funct ICrawlerStrategy.ExtractorAsync()
{
返回(单据)=>返回(单据);
}
}
Edit1-根据@Yahia的要求:
public IObservable<IData> AsyncScraper(HtmlDocument page)
public IObservable异步刮刀(HtmlDocument页)
当尝试创建委托时,我得到一个“错误绑定到目标方法”。当我步进代码时
S您的问题在于传递给CreateDelegate的类型 函数的返回值为
Func<HtmlDocument, IObservable<IData>>
Func
因此,您的委托类型为
Func
因此,更改这一行(您还必须修复其他行以匹配)
action=(Func)
CreateDelegate(typeof(Func),crawler,method);
请显示AsyncScraper
的声明,调用包括FindScrapeMethod
的参数定义。。。
Func<Func<HtmlDocument, IObservable<IData>>>
action = (Func<Func<HtmlDocument, IObservable<IData>>>)
Delegate.CreateDelegate(typeof(Func<Func<HtmlDocument, IObservable<IData>>>), crawler, method);