我有一个通用字典dictionary <string, T>,我想基本上使克隆()..任何建议。


当前回答

这对我来说很好

 // assuming this fills the List
 List<Dictionary<string, string>> obj = this.getData(); 

 List<Dictionary<string, string>> objCopy = new List<Dictionary<string, string>>(obj);

正如Tomer Wolberg在评论中所描述的,如果值类型是可变类,这是行不通的。

其他回答

我将计算T是否为值或引用类型。如果T是值类型,我将使用Dictionary的构造函数,如果T是引用类型,我将确保T继承自ICloneable。

它会给

    private static IDictionary<string, T> Copy<T>(this IDictionary<string, T> dict)
         where T : ICloneable
    {
        if (typeof(T).IsValueType)
        {
            return new Dictionary<string, T>(dict);
        }
        else
        {
            var copy = new Dictionary<string, T>();
            foreach (var pair in dict)
            {
                copy[pair.Key] = pair.Value;
            }
            return copy;
        }
    }

这里是克隆字典的另一种方法,假设你知道做“正确”的事情,只要处理任何隐藏在“T”(a.k.a)后面的东西。“对象”)。

internal static Dictionary<string, object> Clone(Dictionary<string, object> dictIn) 
    {
        Dictionary<string, object> dictOut = new Dictionary<string, object>();
    
        IDictionaryEnumerator enumMyDictionary = dictIn.GetEnumerator();
        while (enumMyDictionary.MoveNext())
        {
            string strKey = (string)enumMyDictionary.Key;
            object oValue = enumMyDictionary.Value;
            dictOut.Add(strKey, oValue);
        }
    
        return dictOut; 
    }

这里是一些真正的“真正的深度复制”,不知道类型用一些递归行走,很适合初学者。我认为它适用于嵌套类型和几乎所有棘手的类型。我还没有添加嵌套数组处理,但是您可以根据自己的选择进行修改。

Dictionary<string, Dictionary<string, dynamic>> buildInfoDict =
    new Dictionary<string, Dictionary<string, dynamic>>()
    {
        {"tag",new Dictionary<string,dynamic>(){
                 { "attrName", "tag"  },
                 { "isCss", "False"  },
               { "turnedOn","True" },
                 { "tag",null }
            } },
        {"id",new Dictionary<string,dynamic>(){
                 { "attrName", "id"  },
                 { "isCss", "False"  },
               { "turnedOn","True" },
                 { "id",null }
            } },
                {"width",new Dictionary<string,dynamic>(){
                 { "attrName", "width"  },
                 { "isCss", "True"  },
               { "turnedOn","True" },
                 { "width","20%" }
            } },
                {"height",new Dictionary<string,dynamic>(){
                 { "attrName", "height"  },
                 { "isCss", "True"  },
               { "turnedOn","True" },
                 { "height","20%" }
            } },
                {"text",new Dictionary<string,dynamic>(){
                 { "attrName", null  },
                 { "isCss", "False"  },
               { "turnedOn","True" },
                 { "text","" }
            } },
                {"href",new Dictionary<string,dynamic>(){
                 { "attrName", null  },
                 { "isCss", "False"  },
                 { "flags", "removeAttrIfTurnedOff"  },
               { "turnedOn","True" },
                 { "href","about:blank" }
            } }
    };

var cln=clone(buildInfoDict);

public static dynamic clone(dynamic obj)
{
    dynamic cloneObj = null;
    if (IsAssignableFrom(obj, typeof(IDictionary)))
    {
        cloneObj = Activator.CreateInstance(obj.GetType());
        foreach (var key in obj.Keys)
        {
            cloneObj[key] = clone(obj[key]);
        }

    }
    else if (IsNumber(obj) || obj.GetType() == typeof(string))
    {
        cloneObj = obj;
    }
    else
    {
        Debugger.Break();
    }
    return cloneObj;
}


public static bool IsAssignableFrom(this object obj, Type ObjType = null, Type ListType = null, bool HandleBaseTypes = false)
{
    if (ObjType == null)
    {
        ObjType = obj.GetType();
    }

    bool Res;

    do
    {
        Res = (ObjType.IsGenericType && ObjType.GetGenericTypeDefinition().IsAssignableFrom(ListType)) ||
            (ListType == null && ObjType.IsAssignableFrom(obj.GetType()));
        ObjType = ObjType.BaseType;
    } while ((!Res && ObjType != null) && HandleBaseTypes && ObjType != typeof(object));

    return Res;
}

public static bool IsNumber(this object value)
{
    return value is sbyte
            || value is byte
            || value is short
            || value is ushort
            || value is int
            || value is uint
            || value is long
            || value is ulong
            || value is float
            || value is double
            || value is decimal;
}

对我来说最好的方法是:

Dictionary<int, int> copy= new Dictionary<int, int>(yourListOrDictionary);

对于。net 2.0,你可以实现一个继承自Dictionary并实现ICloneable的类。

public class CloneableDictionary<TKey, TValue> : Dictionary<TKey, TValue> where TValue : ICloneable
{
    public IDictionary<TKey, TValue> Clone()
    {
        CloneableDictionary<TKey, TValue> clone = new CloneableDictionary<TKey, TValue>();

        foreach (KeyValuePair<TKey, TValue> pair in this)
        {
            clone.Add(pair.Key, (TValue)pair.Value.Clone());
        }

        return clone;
    }
}

然后,只需调用clone方法就可以克隆字典。当然,这个实现要求字典的值类型实现ICloneable,但除此之外,泛型实现根本不实用。