Memory profiling in Xamarin
I'm currently working in a mobile application developed in Xamarin Forms.
There were some signs of memory issues and I finally decided to try Xamarin Profiler.
You'll need to be a Visual Studio Enterprise subscriber to use it, even a trial version will work.
After spending 5 mins reading the documentation and 2 mins running the application with the Profiler I was able to spot an issue: I was creating too many byte arrays.
Locating my code in the stack trace was simple enough.
This is what the function looked like:
public async Task<ImageSource> Adjust(Bitmap bitmap){
var stream = new MemoryStream(); await bitmap.CompressAsync(Bitmap.CompressFormat.Png, 100, stream); var tempFile = Path.GetTempFileName(); var tempFileSteam = new FileStream(tempFile, FileMode.Create); await tempFileSteam.WriteAsync(stream.ToArray(), 0, stream.ToArray().Length); retrun ImageSource.FromFile(tempFile);
}
I created a memory stream to hold a bitmap, I converted it to a byte array twice, before sending it to a file stream, without disposing of it.
The fix was very simple: I used a file stream to hold the bitmap within a using statement
The new function looks like:
public async Task<ImageSource> Adjust(Bitmap bitmap){
var tempFile = Path.GetTempFileName(); using (var stream = new FileStream(tempFile, FileMode.Create))
await bitmap.CompressAsync(Bitmap.CompressFormat.Png, 100, stream);
return ImageSource.FromFile(tempFile);
}
A new execution of the Profiler revealed that the problem with the byte arrays is gone.
Being able to tackle this small issue in a couple of hours is encouraging.
If you want to learn more about Xamarin Profiler visit: