11.4. Determining Whether a File Exists
Problem
You need to determine whether a file exists prior to creating or performing an action on that file.
Solution
Use
the static Exists
method of the
File
class to determine whether a file currently
exists:
if (File.Exists(@"c:\delete\test\test.txt")) { // Operate on that file here }
Discussion
Determining whether a file exists is often critical to your code. If
a file exists and you try to create it using one of the file creation
methods, one of three things will happen: either the existing file
will be overwritten; or, if the file is read-only, an exception will
be thrown; or, an exception will be thrown indicating that the state
of the filesystem is not what you think it is. There is a small
window between the Exists
call and the actions you
take where another process could change the filesystem, so you should
be prepared for that with proper exception handling.
See Also
See the “File Class” topic in the MSDN documentation.
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