基于DateTime属性C#,XPath对XML节点进行排序

Question

我有一个看起来像这样的XML结构.

<sales>
  <item name="Games" sku="MIC28306200" iCat="28" 
     sTime="11/26/2008 8:41:12 AM" 
     price="1.00" desc="Item Name" />
  <item name="Games" sku="MIC28307100" iCat="28" 
     sTime="11/26/2008 8:42:12 AM" 
     price="1.00" desc="Item Name" />
...
</sales>

我试图找到一种方法来根据sTime属性SORT节点,这是一个DateTime.ToString()值.诀窍是我需要保持节点的机智,由于某种原因,我找不到办法做到这一点.我很确定LINQ和XPath有办法做到这一点,但我被卡住了,因为我似乎无法根据DateTime.ToString()值进行排序.

XPathDocument saleResults = new XPathDocument(@"temp/salesData.xml");
XPathNavigator navigator = saleResults.CreateNavigator();

XPathExpression selectExpression = navigator.Compile("sales/item/@sTime");
selectExpression.AddSort("@sTime", 
    XmlSortOrder.Descending, 
    XmlCaseOrder.None, 
    "", 
    XmlDataType.Number);

XPathNodeIterator nodeIterator = navigator.Select(selectExpression);

while( nodeIterator.MoveNext() )
    {
         string checkMe = nodeIterator.Current.Value;
    } 

我还需要维护一个指向NODE的指针来检索其他属性的值.

也许这并不像我想的那么简单.

谢谢.

解决方案:这是我最终使用的内容.获取所选答案和IComparable类,这就是我如何根据sTime属性对XML节点进行排序,然后将所有属性放入相应的Arrays中以便稍后使用.

    XPathDocument saleResults = new XPathDocument(@"temp/salesData.xml");
    XPathNavigator navigator = saleResults.CreateNavigator();
    XPathExpression selectExpression = navigator.Compile("sales/item");
    XPathExpression sortExpr = navigator.Compile("@sTime");
    selectExpression.AddSort(sortExpr, new DateTimeComparer());
    XPathNodeIterator nodeIterator = navigator.Select(selectExpression);
    int i = 0;
    while (nodeIterator.MoveNext())
       {
          if (nodeIterator.Current.MoveToFirstAttribute())
          {
              _iNameList.SetValue(nodeIterator.Current.Value, i);
          }
          if (nodeIterator.Current.MoveToNextAttribute())
          {
              _iSkuList.SetValue(nodeIterator.Current.Value, i);
          }
          ...
          nodeIterator.Current.MoveToParent();
          i++;

      }

Answer 1

XPathExpression.Addsort 有一个重载，它采用 IComparer 接口。如果您自己将比较实现为 IComparer，则可以使用此机制。

 class Program
        {
            static void Main(string[] args)
            {
                XPathDocument saleResults = new XPathDocument( @"salesData.xml" );
                XPathNavigator navigator = saleResults.CreateNavigator( );
                XPathExpression selectExpression = navigator.Compile( "sales/item" );
                XPathExpression sortExpr = navigator.Compile("@sTime");
                selectExpression.AddSort(sortExpr, new DateTimeComparer());
                XPathNodeIterator nodeIterator = navigator.Select( selectExpression );            
                while ( nodeIterator.MoveNext( ) )
                {
                    string checkMe = nodeIterator.Current.Value;
                }
            }
            public class DateTimeComparer : IComparer
            {
                public int Compare(object x, object y)
                {
                    DateTime dt1 = DateTime.Parse( x.ToString( ) );
                    DateTime dt2 = DateTime.Parse( y.ToString( ) );
                    return dt1.CompareTo( dt2 );
                }
            }
        }

Answer 2

干得好:

XmlDocument myDoc = new XmlDocument();

myDoc.LoadXml(@"
<sales>
<item name=""Games""
    sku=""MIC28306200""
    iCat=""28""
    sTime=""11/26/2008 8:41:12 AM""
    price=""1.00""
    desc=""Item Name"" />
<item name=""Games""
    sku=""MIC28307100""
    iCat=""28""
    sTime=""11/26/2008 8:42:12 AM""
    price=""1.00""
    desc=""Item Name"" />
</sales>
");

var sortedItems = myDoc.GetElementsByTagName("item").OfType<XmlElement>()
    .OrderBy(item => DateTime.ParseExact(item.GetAttribute("sTime"), "MM/dd/yyyy h:mm:ss tt", null));

foreach (var item in sortedItems)
{
    Console.WriteLine(item.OuterXml);
}

这是一个完美运行的控制台应用程序.