SelectNodes返回null [重复]

Question

我正在使用 SelectNodes 读取 xml 节点，但是当我尝试 GetElementsByTagName 时，我得到了 null 值。

XmlDocument xml = new XmlDocument();
xml.Load(DownloadFile);
XmlNodeList xmlnode;
xmlnode = xml.GetElementsByTagName("CruisePriceSummaryResponse");

for (int i = 0; i < xmlnode.Count; i++)
{
    XmlNodeList rooms = xml .SelectNodes("RoomSize/CruisePriceSummaryRoomSize");
    for(int j = 0; j < rooms.Count; j++)
    {
        string bestFare = rooms[j].SelectSingleNode("BestFare/TotalPrice").InnerText;
        string fullFare = rooms[j].SelectSingleNode("FullFare/TotalPrice").InnerText;

        // do whatever you need
    }
}

我想从BestFare 和FullFare 中读取TotalPrice 每个孩子都有两个内在孩子BestFare 和FullFareand 我需要读取每个TotalPrice。

这是我的 XML

<?xml version="1.0" encoding="utf-8"?>
<ArrayOfCruisePriceSummaryResponse
    xmlns:i="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://schemas.datacontract.org/2004/07/OpenseasAPI.ServiceModel">

        <CruisePriceSummaryResponse>
            <AvailablePromos
                xmlns:d3p1="http://schemas.microsoft.com/2003/10/Serialization/Arrays">
                <d3p1:string>FLA</d3p1:string>
                <d3p1:string>FLB</d3p1:string>
            </AvailablePromos>
            <Brand>PA</Brand>
            <CruiseCategory i:nil="true"/>
            <RoomSize>
                <CruisePriceSummaryRoomSize>
                    <BestFare>
                        <TotalPrice>2798.0000000</TotalPrice>
                    </BestFare>
                    <FullFare>
                        <TotalPrice>3198.000000</TotalPrice>
                    </FullFare>
                    <PaxCount>2</PaxCount>
                </CruisePriceSummaryRoomSize>
                <CruisePriceSummaryRoomSize>
                    <BestFare>
                        <TotalPrice>2796.000000</TotalPrice>
                    </BestFare>
                    <FullFare>
                        <TotalPrice>4196.000000</TotalPrice>
                    </FullFare>
                    <PaxCount>4</PaxCount>
                </CruisePriceSummaryRoomSize>
            </RoomSize>
            <ShipCode>PD</ShipCode>
        </CruisePriceSummaryResponse>
        <CruisePriceSummaryResponse>
            <AvailablePromos
                xmlns:d3p1="http://schemas.microsoft.com/2003/10/Serialization/Arrays">
                <d3p1:string>FLA</d3p1:string>
                <d3p1:string>LF1</d3p1:string>
            </AvailablePromos>
            <Brand>PA</Brand>
            <RoomSize>
                <CruisePriceSummaryRoomSize>
                    <BestFare>
                        <TotalPrice>1298.000000</TotalPrice>
                    </BestFare>
                    <FullFare>
                        <TotalPrice>3498.000000</TotalPrice>
                    </FullFare>
                    <PaxCount>2</PaxCount>
                </CruisePriceSummaryRoomSize>
                <CruisePriceSummaryRoomSize>
                    <BestFare>
                        <TotalPrice>1796.000000</TotalPrice>
                    </BestFare>
                    <FullFare>
                        <TotalPrice>5396.000000</TotalPrice>
                    </FullFare>
                    <PaxCount>4</PaxCount>
                </CruisePriceSummaryRoomSize>
            </RoomSize>
            <ShipCode>PJ</ShipCode>
        </CruisePriceSummaryResponse>
    </ArrayOfCruisePriceSummaryResponse>

我们将不胜感激。我不想使用 linq，因为这是一个使用 VS2008 的 SSIS 项目，它不支持 linq。

提前致谢

Answer 1

您永远不会加载或读取源 XML。你的代码

XmlDocument xml = new XmlDocument();
XmlNodeList xmlnode;
xmlnode = xml.GetElementsByTagName("CruisePriceSummaryResponse");

创建一个空的 XML 文档，然后尝试从空的 xml 中获取元素。

您需要调用XmlDocument.Load 或XmlDocument.LoadXML 从文件或字符串中读取xml。

XmlDocument xml = new XmlDocument();
xml.Load("pathtosomefile.xml");
XmlNodeList xmlnode = xml.GetElementsByTagName("CruisePriceSummaryResponse");