创建文件而不打开/锁定它？

Question

Does anyone know of a way to (reasonably simple) create a file without actually opening/locking it? In File class, the methods for file creation always return a FileStream. What I want to do is to create a file, rename it (with File.Move) and then use it.

Now I have to:

• Create it
• Close
• Rename
• Reopen for use

Answer 1

Maybe you can try using File.WriteAllText Method (String, String) with the file name and an empty string.

Creates a new file, writes the specified string to the file, and then closes the file. If the target file already exists, it is overwritten.

Answer 2

What about using File.WriteAllBytes method?

// Summary:
//     Creates a new file, writes the specified byte array to the file, and then
//     closes the file. If the target file already exists, it is overwritten.

Answer 3

using (File.Create(...))  { }

While this will briefly open your file (but close it again right away), the code should look quite unobtrusive.

Even if you did some P/Invoke call to a Win32 API function, you would get a file handle. I don't think there's a way to silently create a file without having it open right afterwards.

I think the real issue here is why you go about creating your file in the way you've planned. Creating a file in one place simply to move it to another location doesn't seem very efficient. Is there a particular reason for it?

Answer 4

Incredibly grotty hack, probably the most complicated way to achieve your goal: use Process class

processInfo = new ProcessStartInfo("cmd.exe", "/C " + Command);
processInfo.CreateNoWindow = true; 
processInfo.UseShellExecute = false;
process = process.Start(processInfo);
process.WaitForExit();

where Command would be echo 2>> yourfile.txt

Answer 5

Another way is to use FileStream and Close it after creating the file. It will not lock the file. The code will look like:

FileStream fs = new FileStream(filePath, FileMode.Create);

fs.Flush(true);

fs.Close();

You just after this you can rename it as well or move it some other location.

Below is the Test program to test functionality.

  using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.Text; namespace FileLocking { class Program { static void Main(string[] args) { string str = @"C:\\Test\\TestFileLocking.Processing"; FileIOTest obj = new FileIOTest(); obj.CreateFile(str); } } class FileIOTest { internal void CreateFile(string filePath) { try { //File.Create(filePath); FileStream fs = new FileStream(filePath, FileMode.Create); fs.Flush(true); fs.Close(); TryToAccessFile(filePath); } catch (Exception ex) { Console.WriteLine(ex.Message); } } void TryToAccessFile(string filePath) { try { string newFile = Path.ChangeExtension(filePath, ".locked"); File.Move(filePath, newFile); } catch (Exception ex) { Console.WriteLine(ex.Message); } } } } 

If you use File.Create(commented in above code) then it will give error saying file is being used by another process.