When it is called by trusted applications, opens an existing file for writing.
Assembly: mscorlib (in mscorlib.dll)
The caller does not have the required permission.
path specified a read-only file or directory.
path is a zero-length string, contains only white space, or contains one or more invalid characters as defined by GetInvalidPathChars.
path is null.
The specified path, file name, or both exceed the system-defined maximum length. For example, on Windows-based platforms, paths must be less than 248 characters, and file names must be less than 260 characters.
The specified path is invalid, (for example, it is on an unmapped drive).
The file specified in path was not found.
path is in an invalid format.
For more information about trusted applications, see Trusted Applications.
Silverlight for Windows PhoneThis member has a SecurityCriticalAttribute attribute on Silverlight for Windows Phone, because the attribute was present in Silverlight 3. This attribute restricts this member to internal use. Application code that uses this member throws a MethodAccessException.
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.