The File.Exists(string) method should not be used for path validation, this method merely checks if the file specified in path exists. Passing an invalid path to File.Exists(string) returns false. To check whether the path contains any invalid characters, you can call the Path.GetInvalidPathChars method to retrieve the characters that are invalid for the file system. You can also create a regular expression to test the whether the path is valid for your environment. For examples of acceptable paths, see System.IO.File.

Be aware that another process can potentially do something with the file in between the time you call the File.Exists(string) method and perform another operation on the file, such as File.Delete(string).

The path parameter is permitted to specify relative or absolute path information. Relative path information is interpreted as relative to the current working directory. To obtain the current working directory, see Directory.GetCurrentDirectory.

If path describes a directory, this method returns false. Trailing spaces are removed from the path parameter before determining if the file exists.

The File.Exists(string) method returns false if any error occurs while trying to determine if the specified file exists. This can occur in situations that raise exceptions such as passing a file name with invalid characters or too many characters, a failing or missing disk, or if the caller does not have permission to read the file.

Namespace: System.IO
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 1.0.5000.0, 2.0.0.0, 4.0.0.0