What are the differences between FileStream.Flush(), FlushAsync(), and Dispose()?

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ICSM Computer · Answer

Here’s a clear breakdown of the differences between FileStream.Flush(),
FlushAsync(), and Dispose() in C#:
Flush()
Purpose: Forces all buffered data to be written from memory to disk.SynchronousDoes not close the stream.
fileStream.Flush();
Use when you want to make sure data is written immediately but
continue using the stream.
FlushAsync()
Purpose: Same as Flush(), but performs the operation
asynchronously.Returns a Task, so it can be awaited.Useful for non-blocking I/O in responsive or high-performance applications.
await fileStream.FlushAsync();
Use when you're working in an async method and want to
avoid blocking.
Dispose() (or Close())
Purpose: Flushes buffers and releases all resources, including the underlying file handle.Automatically calls Flush(), then disposes.Once disposed, the stream cannot be reused.
fileStream.Dispose();
// OR with using:
using (var fs = new FileStream(...))
{
    // ... use fs
} // Dispose() is called automatically here
Use when you're done with the stream.
Summary Table:
Method
Flushes Data
Asynchronous
Closes Stream
Flush()
Yes
No
No
FlushAsync()
Yes
Yes
No
Dispose()
Yes
No
Yes
Best Practices:
Use using or await using blocks to ensure Dispose() is always called, even on exceptions.Call Flush() or FlushAsync() if you want to write changes
without closing the file.

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What are the differences between FileStream.Flush(), FlushAsync(), and Dispose()?

ICSM Computer

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1 Answers

`Flush()`

`FlushAsync()`

`Dispose()` (or `Close()`)

Summary Table:

Best Practices:

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