Cache.Insert的委託

我希望能夠在我的緩存更新回調中傳入我的實際解析函數。如何使用代表優化我的代碼重複？由於Cache.Insert的委託

//intial setup code 
public void getJSONContent() //can I pass itemUpdateCallback in here? Does it make sense? 
{ 

    Content = (String)HttpContext.Current.Cache[Path]; 

    if (Content == null) 
    {     
     Content = parseXMLContent(); 

     HttpContext.Current.Cache.Insert(
     key, 
     Content, 
     new CacheDependency(Path), 
     Cache.NoAbsoluteExpiration, 
     Cache.NoSlidingExpiration,  
     jsonUpdateCallback); //callback in the event of my file in cache has changed 
     ^^^^^^^^^^^^^^^^^^ 

    } 
} 

private void jsonUpdateCallback(string key, CacheItemUpdateReason reason, out object value, out CacheDependency dependency, out DateTime exipriation, out TimeSpan slidingExpiration) 
{ 
    dependency = new CacheDependency(key); 
    exipriation = Cache.NoAbsoluteExpiration; 
    slidingExpiration = Cache.NoSlidingExpiration; 
    value = jsonXMLContent(); //how can pass this function into here, so I can can have different parse functions using the same code? 
    ^^^^^^^^^^^^^^^^^^^^^^^^^^ 
} 

//intial setup code 
public void getXMLContent() //can I pass itemUpdateCallback in here? Does it make sense? 
{ 

    Content = (String)HttpContext.Current.Cache[Path]; 

    if (Content == null) 
    {     
     Content = parseXMLContent(); 

     HttpContext.Current.Cache.Insert(
     key, 
     Content, 
     new CacheDependency(Path), 
     Cache.NoAbsoluteExpiration, 
     Cache.NoSlidingExpiration,  
     xmlUpdateCallback); //callback in the event of my file in cache has changed 
     ^^^^^^^^^^^^^^^^^^ 

    } 
} 

private void xmlUpdateCallback(string key, CacheItemUpdateReason reason, out object value, out CacheDependency dependency, out DateTime exipriation, out TimeSpan slidingExpiration) 
{ 
    dependency = new CacheDependency(key); 
    exipriation = Cache.NoAbsoluteExpiration; 
    slidingExpiration = Cache.NoSlidingExpiration; 
    value = parseXMLContent(); //how can pass this function into here, so I can can have different parse functions using the same code? 
    ^^^^^^^^^^^^^^^^^^^^^^^^^^ 
}

來源

2012-06-25 River

那麼，有什麼實際問題？ –

此外，請參閱「[堆棧溢出不允許標題中的標記]（http://meta.stackexchange.com/a/130208）」。 –

thx。我已更新問題。 – River

像這樣：

public void getXMLContent() 
{ 
    getContent(parseXmlContent); 
} 

public void getContent(Func<string> parseContent) 
{ 

    Content = (String)HttpContext.Current.Cache[Path]; 

    if (Content == null) 
    {     
     Content = parseContent(); 

     HttpContext.Current.Cache.Insert(
     key, 
     Content, 
     new CacheDependency(Path), 
     Cache.NoAbsoluteExpiration, 
     Cache.NoSlidingExpiration,  
     delegate(string key2, CacheItemUpdateReason reason, out object value, out CacheDependency dependency, out DateTime expiration, out TimeSpan slidingExpiration) { 
      itemUpdateCallback(key2, reason, parseContent, out value, out dependency, out expiration, out slidingExpiration); 
     }); 
    } 
} 

private void itemUpdateCallback(string key, CacheItemUpdateReason reason, Func<string> parseContent, out object value, out CacheDependency dependency, out DateTime exipriation, out TimeSpan slidingExpiration) 
{ 
    dependency = new CacheDependency(key); 
    exipriation = Cache.NoAbsoluteExpiration; 
    slidingExpiration = Cache.NoSlidingExpiration; 
    value = parseContent(); 
}

來源

2012-06-26 00:26:22 StriplingWarrior

Thx很多。函數 parseContent - 你能否改變這個語法來接受一個通用的逆向類型T？我試過但不可以 – River

@河：內容= parseContent（）'從通用的角度來看是沒有意義的，除非內容本身是一個通用類型。 – StriplingWarrior

這絕對是有一定道理的呼叫傳回，你在你的代碼中的註釋提及。

只是改變：

public void getContent() {...}

到：

public void getContent(Func<TypeOfValue> parsecallback) {...}

，並更改itemUpdateCallBack採取Func<TypeOfValue> parsecallback作爲參數太多。

從外面，你需要的東西是這樣的：

Func<TypeOfValue> func =() => 
{ 
    MethodCall1(); 
    MethodCall2(); 
    return MethodCall3(); 
}; 
myObj.getContent(func);

要麼，你可以把它變成你的構造。它不太靈活，但對於您知道對於給定對象而言這總是相同的情況，它是完美的。

來源

2012-06-26 00:22:46 Blueberry

Cache.Insert的委託

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