我在c#中有一个对象的通用列表,并希望克隆列表。列表中的项是可克隆的,但似乎没有做list. clone()的选项。

有什么简单的办法吗?


当前回答

public static Object CloneType(Object objtype)
{
    Object lstfinal = new Object();

    using (MemoryStream memStream = new MemoryStream())
    {
        BinaryFormatter binaryFormatter = new BinaryFormatter(null, new StreamingContext(StreamingContextStates.Clone));
        binaryFormatter.Serialize(memStream, objtype); memStream.Seek(0, SeekOrigin.Begin);
        lstfinal = binaryFormatter.Deserialize(memStream);
    }

    return lstfinal;
}

其他回答

public static Object CloneType(Object objtype)
{
    Object lstfinal = new Object();

    using (MemoryStream memStream = new MemoryStream())
    {
        BinaryFormatter binaryFormatter = new BinaryFormatter(null, new StreamingContext(StreamingContextStates.Clone));
        binaryFormatter.Serialize(memStream, objtype); memStream.Seek(0, SeekOrigin.Begin);
        lstfinal = binaryFormatter.Deserialize(memStream);
    }

    return lstfinal;
}

对于深度克隆,我使用反射如下:

public List<T> CloneList<T>(IEnumerable<T> listToClone) {
    Type listType = listToClone.GetType();
    Type elementType = listType.GetGenericArguments()[0];
    List<T> listCopy = new List<T>();
    foreach (T item in listToClone) {
        object itemCopy = Activator.CreateInstance(elementType);
        foreach (PropertyInfo property in elementType.GetProperties()) {
            elementType.GetProperty(property.Name).SetValue(itemCopy, property.GetValue(item));
        }
        listCopy.Add((T)itemCopy);
    }
    return listCopy;
}

你可以交替使用List或IEnumerable。

您可以使用扩展方法:

namespace extension
{
    public class ext
    {
        public static List<double> clone(this List<double> t)
        {
            List<double> kop = new List<double>();
            int x;
            for (x = 0; x < t.Count; x++)
            {
                kop.Add(t[x]);
            }
            return kop;
        }
   };

}

你可以通过使用它们的值类型成员来克隆所有对象,例如,考虑这个类:

public class matrix
{
    public List<List<double>> mat;
    public int rows,cols;
    public matrix clone()
    { 
        // create new object
        matrix copy = new matrix();
        // firstly I can directly copy rows and cols because they are value types
        copy.rows = this.rows;  
        copy.cols = this.cols;
        // but now I can no t directly copy mat because it is not value type so
        int x;
        // I assume I have clone method for List<double>
        for(x=0;x<this.mat.count;x++)
        {
            copy.mat.Add(this.mat[x].clone());
        }
        // then mat is cloned
        return copy; // and copy of original is returned 
    }
};

注意:如果你在复制(或克隆)上做了任何改变,它不会影响原始对象。

我已经为我自己做了一些扩展,它转换了ICollection的项目,没有实现IClonable

static class CollectionExtensions
{
    public static ICollection<T> Clone<T>(this ICollection<T> listToClone)
    {
        var array = new T[listToClone.Count];
        listToClone.CopyTo(array,0);
        return array.ToList();
    }
}
public class CloneableList<T> : List<T>, ICloneable where T : ICloneable
{
  public object Clone()
  {
    var clone = new List<T>();
    ForEach(item => clone.Add((T)item.Clone()));
    return clone;
  }
}