System.OutOfMemoryException when calling Path.GetFullPath()

Question

My code here var fullPath = Path.GetFullPath(input); throws OutOfMemoryException Insufficient memory to continue the execution of the program when I pass this value "\\." as argument. Any explanation as to why Path.GetFullPath("\\.") crashes?

XAML:

<TextBox><TextBox.Text><Binding Path="FolderPath" Mode="TwoWay" UpdateSourceTrigger="PropertyChanged" ValidatesOnDataErrors="True" NotifyOnValidationError="True"/></TextBox.Text></TextBox>

ViewModel:

// Implementation of IDataErrorInfo
public string this[string columnName]
{
   get
   {
      if (columnName != null)
      {
         if (columnName.Equals(nameof(FolderPath)))
         {
            if(!Validator.IsValidPath(FolderPath)
                 return "Invalid Folder";
         }
       }
   }
}

Validator Class:

private static bool IsValidPath(string input)
{
   bool isValid = false;
   try
   {
      var fullPath = Path.GetFullPath(input);
      return input.Equals(fullPath, StringComparison.InvariantCultureIgnoreCase);
   }
   catch (Exception)
   {
      isValid = false;
   }
   return isValid;
}

Does this happen when you are debugging? What is the path to the executable that is calling that code? — Logarr, Jan 18 '18 at 02:46
Sounds like leaking file handles. Are you calling that function in a loop, in rapid succession? If you are try a `System.Threading.Thread.Sleep(100)` .. — Jeremy Thompson, Jan 18 '18 at 02:49
@JeremyThompson this method is called when text is changed in textbox — mark uy, Jan 18 '18 at 02:59
@markuy please post a complete minimal example of the code that causes this. Something isn't making sense here. Jeremy is likely right, and I think your code is doing something else that you don't notice or understand. — Logarr, Jan 18 '18 at 03:08
@Logarr Thanks. I updated the post with the sample implementation — mark uy, Jan 18 '18 at 03:21
@RawitasKrungkaew it does not occur in x64. the crash happens when I set the Build Platform target as Any CPU and check the Prefer 32-bit tickbox — mark uy, Jan 18 '18 at 05:09

Jeremy Thompson · Answer 1 · 2018-01-18T04:22:45.027

0

Any explanation as to why Path.GetFullPath("\.") crashes?

Per MSDN: https://msdn.microsoft.com/en-us/library/system.io.path.getfullpath(v=vs.110).aspx

Remarks
The .NET Framework does not support direct access to physical disks through paths that are device names, such as "\.\PHYSICALDRIVE0 ".

You'll either need to use pinvoke, Direct disk access in windows (C#) or perhaps this library might help CCS LABS C#: Low Level Disk Access.

edited Jan 18 '18 at 04:22

answered Jan 18 '18 at 04:15

Jeremy Thompson

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thanks Jeremy. we've narrowed down the cause and as what Rawitas mentioned, it could be related to the build platform. My code above works if target platform is x64. But when I set it to x32 or Any CPU with preferred 32-bit, it gives the memory exception – mark uy Jan 18 '18 at 05:15
@markuy That's what is known as an X Y problem. You shouldn't be running out of memory for such a simple process. The memory usage is a symptom of a bigger problem. – Logarr Jan 18 '18 at 05:43

System.OutOfMemoryException when calling Path.GetFullPath()

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