c# - IDictionary 到字符串

Question

我创建了一个 IDictionary 扩展来将 IDictionary Exception.Data 值写入字符串。

扩展代码:

public static class DictionaryExtension
{
    public static string ToString<TKey, TValue>(this IDictionary<TKey, TValue> source, string keyValueSeparator, string sequenceSeparator)
    {
        if (source == null)
            throw new ArgumentException("Parameter source can not be null.");

        return source.Aggregate(new StringBuilder(), (sb, x) => sb.Append(x.Key + keyValueSeparator + x.Value + sequenceSeparator), sb => sb.ToString(0, sb.Length - 1));           
    }
}

当我在 Exception.Data.ToString("=", "|") 上使用此扩展时，出现错误

无法从用法中推断类型参数。

知道如何解决这个问题吗？

Answer 1

Exception.Data 类型为 IDictionary , 不是 IDictionary<TKey, TValue> .

您需要将扩展​​方法更改为:

public static string ToString(this IDictionary source, string keyValueSeparator,
                                                       string sequenceSeparator) 
{ 
    if (source == null) 
        throw new ArgumentException("Parameter source can not be null."); 

    return source.Cast<DictionaryEntry>()
                 .Aggregate(new StringBuilder(),
                            (sb, x) => sb.Append(x.Key + keyValueSeparator + x.Value
                                                  + sequenceSeparator),
                            sb => sb.ToString(0, sb.Length - 1));            
}