求助关于xml SelectSingleNode取值的问题
xml文件
<?xml version="1.0" encoding="utf-8"?>
<Report xmlns:rd="http://schemas.microsoft.com/SQLServer/reporting/reportdesigner" xmlns="http://schemas.microsoft.com/sqlserver/reporting/2008/01/reportdefinition">
<DataSources>
<DataSource Name="ds">
<ConnectionProperties>
<DataProvider>System.Data.DataSet</DataProvider>
<ConnectString>/* Local Connection */</ConnectString>
</ConnectionProperties>
<rd:DataSourceID>4601aaa3-4033-415b-b89f-d06d9bb1c2a4</rd:DataSourceID>
</DataSource>
</DataSources>
<Body>
<ReportItems>
<Textbox Name="Textbox1">
<CanGrow>true</CanGrow>
<KeepTogether>true</KeepTogether>
<Paragraphs>
<Paragraph>
<TextRuns>
<TextRun>
<Value>M型及二维</Value>
<Style>
<FontFamily>宋体</FontFamily>
</Style>
</TextRun>
</TextRuns>
<Style>
<TextAlign>Center</TextAlign>
</Style>
</Paragraph>
</Paragraphs>
<rd:DefaultName>Textbox1</rd:DefaultName>
<Top>0.03175cm</Top>
<Left>0.03306cm</Left>
<Height>0.6cm</Height>
<Width>10.22459cm</Width>
<Style>
<Border>
<Style>Solid</Style>
</Border>
<PaddingLeft>2pt</PaddingLeft>
<PaddingRight>2pt</PaddingRight>
<PaddingTop>2pt</PaddingTop>
<PaddingBottom>2pt</PaddingBottom>
</Style>
</Textbox>
<Textbox Name="Textbox2">
<CanGrow>true</CanGrow>
<KeepTogether>true</KeepTogether>
<Paragraphs>
<Paragraph>
<TextRuns>
<TextRun>
<Value>主
动
脉</Value>
<Style>
<FontFamily>宋体</FontFamily>
</Style>
</TextRun>
</TextRuns>
<Style>
<TextAlign>Center</TextAlign>
</Style>
</Paragraph>
</Paragraphs>
<rd:DefaultName>Textbox1</rd:DefaultName>
<Top>0.63175cm</Top>
<Left>0.03306cm</Left>
<Height>1.8cm</Height>
<Width>0.96542cm</Width>
<ZIndex>1</ZIndex>
<Style>
<Border>
<Style>Solid</Style>
</Border>
<PaddingLeft>2pt</PaddingLeft>
<PaddingRight>2pt</Padding