- 1 year ago
How to save files using Microsoft.Win32.SaveFileDialog with filenames longer than MAX_PATH?
In Windows, the MAX_PATH
limitation (260 characters) can be a challenge when saving files with filenames longer than this limit using the Microsoft.Win32.SaveFileDialog
. However, you can use the extended-length path prefix (\?) to bypass this limitation and save files with longer filenames.
Here's how you can do it:
Prefix the filename with
\\?\
:
Before passing the filename to theSaveFileDialog
, you need to add the extended-length path prefix\\?\
to the beginning of the filename. This tells Windows to treat the path as a long path and bypass theMAX_PATH
limitation.Check for support:
Not all applications and file systems support extended-length paths. Before using the extended-length path, you should check if the target file system (e.g., NTFS) and the application that will use the file support it.Handle potential issues:
Using extended-length paths might cause compatibility issues with some applications. For example, if you plan to share the saved files with other applications or systems, they might not recognize the extended-length path. Be sure to test the behavior with the specific applications that will interact with these files.
Here's a code example in C# showing how to use the Microsoft.Win32.SaveFileDialog
with filenames longer than MAX_PATH
:
csharpusing Microsoft.Win32;
using System;
using System.IO;
public class Program
{
public static void Main()
{
SaveFileDialog saveFileDialog = new SaveFileDialog();
saveFileDialog.FileName = @"\\?\C:\LongFolderPath\LongFileName.txt"; // Add the \\?\ prefix
if (saveFileDialog.ShowDialog() == true)
{
string filePath = saveFileDialog.FileName;
// Do further processing with the filePath
// For example, create and save the file
try
{
File.WriteAllText(filePath, "This is some content.");
Console.WriteLine("File saved successfully.");
}
catch (Exception ex)
{
Console.WriteLine("Error saving file: " + ex.Message);
}
}
}
}
Remember to replace "C:\LongFolderPath\LongFileName.txt"
with the desired path and filename you want to save.
Again, be cautious when using extended-length paths, as not all applications and systems may support them. Consider the specific use case and compatibility requirements before using this approach.