C#中“未找到网络路径”和“拒绝访问”之间的区别

try
{
    string[] contents = Directory.GetFileSystemEntries( path );
}
catch( Exception e )
{
    if( e is DirectoryNotFoundException )
        MessageBox.Show( "Path not found" );
    else
        MessageBox.Show( "Access denied" );
}

这适用于本地路径,但对于网络路径,异常始终是System.IO.IOException,无论错误原因如何.异常消息字段根据路径是否存在显示不同的消息,所以很明显信息在某些时候可用,但我无法实现.有没有办法区分网络路径的“未找到路径”和“拒绝访问”？

编辑：所以,如果其他人想要快速解决这个问题,如henrik建议,并纳入peSHIr的建议,这里是你可以做的：

try
{
    // Issue this call just to find out whether the path exists
    // We don't care about the result

    string[] contents = Directory.GetFileSystemEntries( path );

    // If we get this far then the path exists.
}
catch( IOException e )
{
    uint error = (uint)Marshal.GetHRForException( e );

    if( error == (uint)0x80070041 )     // ERROR_NETWORK_ACCESS_DENIED
    {
        // The poor deluded user doesn't have access rights

        this.SuperProprietaryTechniqueForGettingAccessRights();
    }
    else
    {
        // Hah! The idiot user specified a path that doesn't exist!
        // Chastise them severely,like all good GUI should.

        MessageBox.Show( "NO! BAD USER!" );
    }
}
catch 
{
    // Swallow all other types of exception - we only made the call
    // to find out whether the path exists.
}