Saving files in MAUI

Question

I'm writing a text editor in MAUI and encountered a problem that when executing this code (on Windows 10), the error "Exception raised: "System.UnauthorizedAccessException" in System.Private.CoreLib.dll". Tried googling how to allow the application to access the file system, but in vain

private async Task HandleSaveClick()
{
    if (!string.IsNullOrEmpty(fileContent) && !string.IsNullOrEmpty(filePath))
    {
        var fileData = Encoding.UTF8.GetBytes(fileContent);
        using (FileStream stream = new FileStream(filePath, FileMode.Create))
        {
            await stream.WriteAsync(fileData, 0, fileData.Length);
        }
    }
}

score 4 · Accepted Answer · answered May 23 '23 at 07:40

4

MAUI's developer team recently launched the official file storage API, which you could refer to FileSaver for more details.

answered May 23 '23 at 07:40

Alec - MSFT

121
4

Liyun Zhang - MSFT · Answer 2 · 2023-03-30T08:37:45.120

0

Can you show the details about the file path? This error means the file path you are trying to access is denied by the system. I have created a sample to save the file in the Folder metioned in the official document about the Maui File System Helper.

using (FileStream filestream = new FileStream(Path.Combine(FileSystem.CacheDirectory, "Test.txt"), FileMode.Create))
{
    var data = Encoding.UTF8.GetBytes("this is content");
    await filestream.WriteAsync(data,0,data.Length);
}

And the file will be saved into the FileSystem.CacheDirectory.

edited Mar 30 '23 at 08:37

answered Mar 30 '23 at 08:31

Liyun Zhang - MSFT

8,271
1
2
14

the file is chosen by the user. – Ilya Vasunin Mar 30 '23 at 11:10
https://github.com/Genolium/LiveCode/blob/master/LiveCode/Pages/FetchData.razor – Ilya Vasunin Mar 30 '23 at 11:11
You can try to test with my code to check if the cause is the file path or not. @IlyaVasunin – Liyun Zhang - MSFT Mar 31 '23 at 06:45
Well you just made a rewrite of what I had written in my post. Literally the same code – Ilya Vasunin Mar 31 '23 at 15:31
This code can run successfully in my project. – Liyun Zhang - MSFT Apr 03 '23 at 09:05

Saving files in MAUI

2 Answers2