UWP: byte[] to file

Question

I have a byte[] and I want to store it into a file. This is my code:

using System.Runtime.InteropServices.WindowsRuntime;

StorageFolder folder = await GetStorageFolderFromFilePath(filePath);
StorageFile file = await folder.CreateFileAsync(Path.GetFileName(filePath), CreationCollisionOption.ReplaceExisting);

using (Stream stream = await file.OpenStreamForWriteAsync())
{
    IBuffer buffer = byteArray.AsBuffer();
    await FileIO.WriteBufferAsync(file, buffer);
}

A file is created but the file is empty. What am I doing wrong?

score 7 · Accepted Answer · answered Mar 18 '16 at 14:34

7

Why did you do not use FileIO.WriteBytesAsync method?

public static IAsyncAction WriteBytesAsync(IStorageFile file, System.Byte[] buffer);

You can do it in one line code:

await FileIO.WriteBytesAsync(storageFile, byteArray);

answered Mar 18 '16 at 14:34

Andrii Krupka

4,276
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Can you add the line of code where you create `storageFile`? – Christian Nov 05 '18 at 12:40
@Christian you can look this post https://learn.microsoft.com/en-us/windows/uwp/files/quickstart-reading-and-writing-files – Andrii Krupka Nov 05 '18 at 14:12

score 0 · Answer 2 · edited May 23 '17 at 11:46

0

I think you'll find your solution here save stream to file in c# and winrt

basically, u need to read from your buffer.

edited May 23 '17 at 11:46

Community

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answered Mar 18 '16 at 13:54

makro88

102
8

score -1 · Answer 3 · answered Mar 18 '16 at 13:53

-1

maybe you should try this way:

System.IO.File.WriteAllBytes(path,bytes)

path - path to file, bytes - file

answered Mar 18 '16 at 13:53

Dawid Krzuś

19
3

It's code for usual Desktop C# version. You can't do it in Windows Phone / WinRT / UWP applications – Andrii Krupka Mar 18 '16 at 14:36
1

System.IO.File.WriteAllBytes is available to UWP apps. Just make sure the path is in the app data folder for write access – Rob Caplan - MSFT Mar 18 '16 at 20:36

UWP: byte[] to file

3 Answers3