c# - XDocument.load(string uri) 抛出 ArgumentNullException

Question

调用时出现 ArgumentNullException

string filepath = @"AppData\TestAppData.xml";
        if (filepath != null)
        {
            XDocument xdoc = XDocument.Load(filepath); 
        }

以下是异常详细信息。它说，“格式”参数为空 - 但在什么时候我可以控制这个参数？或者我的错误到底是什么？

> System.ArgumentNullException was unhandled by user code
>     HResult=-2147467261
>     Message=Value cannot be null.
>     Parameter name: format
>     ParamName=format
>     Source=mscorlib
>     StackTrace:
>        at System.String.FormatHelper(IFormatProvider provider, String format,   ParamsArray args)
>        at System.String.Format(String format, Object[] args)
>        at System.SR.Format(String resourceFormat, Object[] args)
>        at System.Xml.XmlException.CreateMessage(String res, String[] args, Int32 lineNumber, Int32 linePosition)
>        at System.Xml.XmlException..ctor(String res, String[] args, Exception innerException, Int32 lineNumber, Int32 linePosition, String
> sourceUri)
>        at System.Xml.XmlTextReaderImpl.Throw(String res, String arg)
>        at System.Xml.XmlTextReaderImpl.ParseAttributeValueSlow(Int32 curPos, Char quoteChar, NodeData attr)
>        at System.Xml.XmlTextReaderImpl.ParseAttributes()
>        at System.Xml.XmlTextReaderImpl.ParseElement()
>        at System.Xml.XmlTextReaderImpl.ParseElementContent()
>        at System.Xml.XmlTextReaderImpl.Read()
>        at System.Xml.Linq.XContainer.ReadContentFrom(XmlReader r)
>        at System.Xml.Linq.XContainer.ReadContentFrom(XmlReader r, LoadOptions o)
>        at System.Xml.Linq.XDocument.Load(XmlReader reader, LoadOptions options)
>        at System.Xml.Linq.XDocument.Load(String uri, LoadOptions options)
>        at System.Xml.Linq.XDocument.Load(String uri)

Answer 1

你需要这个

string EnviromentPath = Path.GetDirectoryName(HostingEnvironment.ApplicationPhysicalPath);

获取项目目录的路径，然后您应该在此之后将它们组合起来

Path.Combine(EnviromentPath,@"AppData\TestAppData.xml");

Answer 2

看看这个：How I use XDocument.Load() to get a file in the application directory

好像文件路径不正确，试试这个

XDocument xdoc = XDocument.Load(filepath);