Path​Too​Long​Exception Class

Definition

The exception that is thrown when a path or fully qualified file name is longer than the system-defined maximum length.

[System.Runtime.InteropServices.ComVisible(true)]
public class PathTooLongException : System.IO.IOException
Inheritance
PathTooLongException
Attributes

Inherited Members

System.Exception

System.Object

Remarks

If your code does not have FileIOPermissionAttribute.PathDiscovery permission, the error message for this exception may contain only file or directory names instead of full paths.

In apps that run under versions of the .NET Framework prior to the .NET Framework 4.6.2, full paths must not exceed 260 characters to maintain compatibility with Windows operating systems. Any path in excess of 260 characters automatically throws a PathTooLongException. For more information about this restriction, see the entry Long Paths in .NET in the BCL Team blog.

Note

This exception is not included in .NET for Windows Store apps or the Portable Class Library, but it is thrown by some members that are. To catch the exception in that case, write a catch statement that handles an IOException instead.

Starting with apps running under the .NET Framework 4.6.2, the .NET Framework supports long paths in excess of 260 (or MAX_PATH) characters. The conditions under which a PathTooLongException exception are thrown depend on the version of the .NET Framework that an app targets:

Apps that target the .NET Framework 4.6.2 and later versions
Long paths are supported by default. The runtime throws a PathTooLongException under the following conditions:

  • The operating system returns COR_E_PATHTOOLONG or its equivalent.

  • The length of the path exceeds Int16.MaxValue (32,767) characters.

Apps that target the .NET Framework 4.6.1 and earlier versions
Long paths are disabled by default, and the legacy behavior is maintained. The runtime throws a PathTooLongException whenever a path exceeds 260 characters.

If this is undesirable, apps that target the .NET Framework 4.6.1 and earlier but run under the .NET Framework 4.6.2 can enable long path support by including the following setting in the <runtime> element of the application configuration file:


<runtime>   
   <AppContextSwitchOverrides value="Switch.System.IO.UseLegacyPathHandling=false" />   
</runtime>  

PathTooLongException uses the HRESULT COR_E_PATHTOOLONG, which has the value 0x800700CE.

Constructors

Path​Too​Long​Exception()

Initializes a new instance of the PathTooLongException class with its HRESULT set to COR_E_PATHTOOLONG.

Path​Too​Long​Exception(​String)

Initializes a new instance of the PathTooLongException class with its message string set to message and its HRESULT set to COR_E_PATHTOOLONG.

Path​Too​Long​Exception(​Serialization​Info, ​Streaming​Context)

Initializes a new instance of the PathTooLongException class with the specified serialization and context information.

Path​Too​Long​Exception(​String, ​Exception)

Initializes a new instance of the PathTooLongException class with a specified error message and a reference to the inner exception that is the cause of this exception.