c# - 复制列表值

Question

当我调用此方法时，总是更改原始列表“printRowList”中的值，我不想更改原始值。我只需要更改临时列表的值，即“tempRowModellist”。我能做什么？

private List<PrintRowModel> SetTemplateSettingsData(
    List<PrintRowModel> printRowList, 
    object value)
{
    List<PrintRowModel> tempRowModellist = new List<PrintRowModel>();
    tempRowModellist.AddRange(printRowList);

    foreach (PrintRowModel printRow in tempRowModellist )
    {
        foreach (PrintColumnModel printColumn in printRow)
        {
            printColumn.Value = 
                GetObjectValues(printColumn.Value, value).ToString();
        }
    }

    return newList;
}

Answer 1

因为你还在引用原来的列表。如果您不想修改它，则需要克隆它。改变这个

tempRowModellist.AddRange(printRowList);`

作为

tempRowModellist = printRowList.Clone().ToList();

添加这个extension method

static class Extensions
{
    public static List<T> Clone<T>(this List<T> listToClone) where T: ICloneable
    {
        return listToClone.Select(item => (T)item.Clone()).ToList();
    }
}

注意:确保你的类实现了 I Cloneable interface .