XSL什么都不返回

Question

我是编写XSL的新手。 我试图使用XSLT从XML文件中提取一些数据。

XML文件和XSL文件如下所示。

这是我的XML文件（完全不是提取物; - ）：

<?xml version="1.0" encoding="UTF-8"?>
<AggregatedBillData xmlns="http://www.atrias.be/migdgo/20150630/Bill/AggregatedBillData" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:ent="http://www.atrias.be/migdgo/20150630/Entities" xsi:schemaLocation="http://www.atrias.be/migdgo/20150630/Bill/AggregatedBillData ../../Messages/Bill/DGO-BI-INT-50-AggregatedBillData.xsd">
<HeaderMessage>
    <ent:MessageId>d83c111c-e655-4481-8022-fb2e0e88dd4a</ent:MessageId>
    <ent:MessageDateTime>2018-07-11T12:00:00+02:00</ent:MessageDateTime>
    <ent:ContextId>011c38c8-71f6-4730-bf44-2ca1f9d2f12e</ent:ContextId>
    <ent:Module>I81</ent:Module>
    <ent:Label>IA2</ent:Label>
    <ent:Sector>23</ent:Sector>
    <ent:SenderId>5414495999995</ent:SenderId>
    <ent:ReceiverId>5414488009809</ent:ReceiverId>
    <ent:MinorVersion>0</ent:MinorVersion>
</HeaderMessage>
<Invoice>
    <Id>0</Id>
    <Sector>23</Sector>
    <BillType>IE6</BillType>
    <BillPurpose>IE5</BillPurpose>
    <RectificationFlag>false</RectificationFlag>
    <CalculationDateTime>2018-01-01T12:00:00+01:00</CalculationDateTime>
    <GridAccessProvider>
        <ent:EanGln>5499780282808</ent:EanGln>
    </GridAccessProvider>
    <InvoiceLine>
        <LineNumber>500004500000001</LineNumber>
        <Amount>250</Amount>
        <Currency>EUR</Currency>
        <Quantity>1000</Quantity>
        <Unit>KWH</Unit>
        <ConsumptionMonth>--01</ConsumptionMonth>
        <CreditLineFlag>false</CreditLineFlag>
        <TariffComponent>
            <Code>?</Code>
            <Direction>E17</Direction>
            <CostCategory>D</CostCategory>
            <VatRate>0.21</VatRate>
            <GlobalisationCode>
                <Code>E</Code>
            </GlobalisationCode>
            <Tariff>
                <Code>T220</Code>
            </Tariff>
        </TariffComponent>
    </InvoiceLine>
    <InvoiceLine>
        <LineNumber>500004500000002</LineNumber>
        <Amount>250</Amount>
        <Currency>EUR</Currency>
        <Quantity>1000</Quantity>
        <Unit>KWH</Unit>
        <ConsumptionMonth>--02</ConsumptionMonth>
        <CreditLineFlag>false</CreditLineFlag>
        <TariffComponent>
            <Code>?</Code>
            <Direction>E17</Direction>
            <CostCategory>D</CostCategory>
            <VatRate>0.21</VatRate>
            <GlobalisationCode>
                <Code>E</Code>
            </GlobalisationCode>
            <Tariff>
                <Code>T220</Code>
            </Tariff>
        </TariffComponent>
    </InvoiceLine>
    <InvoiceLine>
        <LineNumber>500004500000003</LineNumber>
        <Amount>250</Amount>
        <Currency>EUR</Currency>
        <Quantity>1000</Quantity>
        <Unit>KWH</Unit>
        <ConsumptionMonth>--03</ConsumptionMonth>
        <CreditLineFlag>false</CreditLineFlag>
        <TariffComponent>
            <Code>?</Code>
            <Direction>E17</Direction>
            <CostCategory>D</CostCategory>
            <VatRate>0.21</VatRate>
            <GlobalisationCode>
                <Code>E</Code>
            </GlobalisationCode>
            <Tariff>
                <Code>T220</Code>
            </Tariff>
        </TariffComponent>
    </InvoiceLine>
    <InvoiceLine>
        <LineNumber>500004500000004</LineNumber>
        <Amount>250</Amount>
        <Currency>EUR</Currency>
        <Quantity>1000</Quantity>
        <Unit>KWH</Unit>
        <ConsumptionMonth>--04</ConsumptionMonth>
        <CreditLineFlag>false</CreditLineFlag>
        <TariffComponent>
            <Code>?</Code>
            <Direction>E17</Direction>
            <CostCategory>D</CostCategory>
            <VatRate>0.21</VatRate>
            <GlobalisationCode>
                <Code>E</Code>
            </GlobalisationCode>
            <Tariff>
                <Code>T220</Code>
            </Tariff>
        </TariffComponent>
    </InvoiceLine>
    <InvoiceLine>
        <LineNumber>500004500000005</LineNumber>
        <Amount>250</Amount>
        <Currency>EUR</Currency>
        <Quantity>1000</Quantity>
        <Unit>KWH</Unit>
        <ConsumptionMonth>--05</ConsumptionMonth>
        <CreditLineFlag>false</CreditLineFlag>
        <TariffComponent>
            <Code>?</Code>
            <Direction>E17</Direction>
            <CostCategory>D</CostCategory>
            <VatRate>0.21</VatRate>
            <GlobalisationCode>
                <Code>E</Code>
            </GlobalisationCode>
            <Tariff>
                <Code>T220</Code>
            </Tariff>
        </TariffComponent>
    </InvoiceLine>
    <InvoiceLine>
        <LineNumber>500004500000006</LineNumber>
        <Amount>250</Amount>
        <Currency>EUR</Currency>
        <Quantity>1000</Quantity>
        <Unit>KWH</Unit>
        <ConsumptionMonth>--06</ConsumptionMonth>
        <CreditLineFlag>false</CreditLineFlag>
        <TariffComponent>
            <Code>?</Code>
            <Direction>E17</Direction>
            <CostCategory>D</CostCategory>
            <VatRate>0.21</VatRate>
            <GlobalisationCode>
                <Code>E</Code>
            </GlobalisationCode>
            <Tariff>
                <Code>T220</Code>
            </Tariff>
        </TariffComponent>
    </InvoiceLine>
    <InvoiceLine>
        <LineNumber>500004500000007</LineNumber>
        <Amount>250</Amount>
        <Currency>EUR</Currency>
        <Quantity>1000</Quantity>
        <Unit>KWH</Unit>
        <ConsumptionMonth>--07</ConsumptionMonth>
        <CreditLineFlag>false</CreditLineFlag>
        <TariffComponent>
            <Code>?</Code>
            <Direction>E17</Direction>
            <CostCategory>D</CostCategory>
            <VatRate>0.21</VatRate>
            <GlobalisationCode>
                <Code>E</Code>
            </GlobalisationCode>
            <Tariff>
                <Code>T220</Code>
            </Tariff>
        </TariffComponent>
    </InvoiceLine>
    <InvoiceLine>
        <LineNumber>500004500000008</LineNumber>
        <Amount>250</Amount>
        <Currency>EUR</Currency>
        <Quantity>1000</Quantity>
        <Unit>KWH</Unit>
        <ConsumptionMonth>--08</ConsumptionMonth>
        <CreditLineFlag>false</CreditLineFlag>
        <TariffComponent>
            <Code>?</Code>
            <Direction>E17</Direction>
            <CostCategory>D</CostCategory>
            <VatRate>0.21</VatRate>
            <GlobalisationCode>
                <Code>E</Code>
            </GlobalisationCode>
            <Tariff>
                <Code>T220</Code>
            </Tariff>
        </TariffComponent>
    </InvoiceLine>
    <InvoiceLine>
        <LineNumber>500004500000009</LineNumber>
        <Amount>250</Amount>
        <Currency>EUR</Currency>
        <Quantity>1000</Quantity>
        <Unit>KWH</Unit>
        <ConsumptionMonth>--09</ConsumptionMonth>
        <CreditLineFlag>false</CreditLineFlag>
        <TariffComponent>
            <Code>?</Code>
            <Direction>E17</Direction>
            <CostCategory>D</CostCategory>
            <VatRate>0.21</VatRate>
            <GlobalisationCode>
                <Code>E</Code>
            </GlobalisationCode>
            <Tariff>
                <Code>T220</Code>
            </Tariff>
        </TariffComponent>
    </InvoiceLine>
    <InvoiceLine>
        <LineNumber>500004500000010</LineNumber>
        <Amount>250</Amount>
        <Currency>EUR</Currency>
        <Quantity>1000</Quantity>
        <Unit>KWH</Unit>
        <ConsumptionMonth>--10</ConsumptionMonth>
        <CreditLineFlag>false</CreditLineFlag>
        <TariffComponent>
            <Code>?</Code>
            <Direction>E17</Direction>
            <CostCategory>D</CostCategory>
            <VatRate>0.21</VatRate>
            <GlobalisationCode>
                <Code>E</Code>
            </GlobalisationCode>
            <Tariff>
                <Code>T220</Code>
            </Tariff>
        </TariffComponent>
    </InvoiceLine>
    <InvoiceLine>
        <LineNumber>500004500000011</LineNumber>
        <Amount>250</Amount>
        <Currency>EUR</Currency>
        <Quantity>1000</Quantity>
        <Unit>KWH</Unit>
        <ConsumptionMonth>--11</ConsumptionMonth>
        <CreditLineFlag>false</CreditLineFlag>
        <TariffComponent>
            <Code>?</Code>
            <Direction>E17</Direction>
            <CostCategory>D</CostCategory>
            <VatRate>0.21</VatRate>
            <GlobalisationCode>
                <Code>E</Code>
            </GlobalisationCode>
            <Tariff>
                <Code>T220</Code>
            </Tariff>
        </TariffComponent>
    </InvoiceLine>
    <InvoiceLine>
        <LineNumber>500004500000012</LineNumber>
        <Amount>250</Amount>
        <Currency>EUR</Currency>
        <Quantity>1000</Quantity>
        <Unit>KWH</Unit>
        <ConsumptionMonth>--12</ConsumptionMonth>
        <CreditLineFlag>false</CreditLineFlag>
        <TariffComponent>
            <Code>?</Code>
            <Direction>E17</Direction>
            <CostCategory>D</CostCategory>
            <VatRate>0.21</VatRate>
            <GlobalisationCode>
                <Code>E</Code>
            </GlobalisationCode>
            <Tariff>
                <Code>T220</Code>
            </Tariff>
        </TariffComponent>
    </InvoiceLine>
    <MarketParty>
        <ent:EanGln>0000000000000</ent:EanGln>
    </MarketParty>  
    <BillArea>
        <Id>4444</Id>
        <Sector>23</Sector>
    </BillArea>
</Invoice>
<AggregationRun>
    <ent:Id>1</ent:Id>
    <ent:NumberOfAggregations>12</ent:NumberOfAggregations>
    <ent:TotalAmount>1200</ent:TotalAmount>
    <ent:Aggregation>
        <ent:Id>1</ent:Id>
        <ent:TotalAmount>100</ent:TotalAmount>
    </ent:Aggregation>
</AggregationRun>

我正在尝试使用以下XSLT显示每个InvoiceLine的LineNumber和Amount：

   <?xml version="1.0" encoding="UTF-8"?>
   <xsl:stylesheet version="1.0" mlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:fo="http://www.w3.org/1999/XSL/Format">
    <xsl:template match="/">
        <html>
            <body>
                <h2>Aggregated Bill</h2>
                <table border="1">
                    <tr bgcolor="#9acd32">
                        <th>LineNumber</th>
                        <th>Amount</th>
                    </tr>
                    <xsl:for-each select="AggregatedBillData/Invoice/InvoiceLine">
                        <tr>
                            <td>
                                <xsl:value-of select="LineNumber"/>
                            </td>
                            <td>
                                <xsl:value-of select="Amount"/>
                            </td>
                        </tr>
                    </xsl:for-each>
                </table>
            </body>
        </html>
    </xsl:template>
    </xsl:stylesheet>

XSLT什么都不返回。

有什么问题？

非常感谢提前。

尼古拉斯

Answer 1

您在源XML中声明了一个默认命名空间： xmlns="http://www.atrias.be/migdgo/20150630/Bill/AggregatedBillData"

您需要将此声明（包括名称空间前缀）添加到XSLT并在XPath表达式中使用它：

   <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:fo="http://www.w3.org/1999/XSL/Format" xmlns:my="http://www.atrias.be/migdgo/20150630/Bill/AggregatedBillData">
    <xsl:template match="/">
        <html>
            <body>
                <h2>Aggregated Bill</h2>
                <table border="1">
                    <tr bgcolor="#9acd32">
                        <th>LineNumber</th>
                        <th>Amount</th>
                    </tr>
                    <xsl:for-each select="my:AggregatedBillData/my:Invoice/my:InvoiceLine">
                        <tr>
                            <td>
                                <xsl:value-of select="my:LineNumber"/>
                            </td>
                            <td>
                                <xsl:value-of select="my:Amount"/>
                            </td>
                        </tr>
                    </xsl:for-each>
                </table>
            </body>
        </html>
    </xsl:template>
    </xsl:stylesheet>

您必须提供一些前缀才能在XPath中引用该命名空间中的元素。

如果您查看this MSDN page，它会解释一下XPath如何将空前缀视为 null 命名空间：

  

XPath将空前缀视为null命名空间。换句话说，只有映射到名称空间的前缀才能用于XPath查询。这意味着如果要查询XML文档中的命名空间，即使它是默认命名空间，也需要为其定义前缀。   例如，如果没有为上面的XML文档定义前缀，XPath查询/书籍/书籍将不会返回任何结果。   必须绑定前缀以防止在查询某些节点不在命名空间中的文档时出现歧义，并且某些节点在默认命名空间中。