Using FilePicker one can open an existing file:
FileResult file = await FilePicker.PickAsync();
TextView textview = FindViewById<TextView>(Resource.Id.textview);
string path = file.FullPath;
var handle = File.Open(path, FileMode.OpenOrCreate);
byte[] data = new byte[10];
handle.Read(data, 0, 10);
Is there a similar way for saving a new file?
For now, the FilePicker plugin is only designed to pick existing files.
On Android and iOS, you could not do that. But on UWP, you could use the FileSavePicker
.
Xamarin: https://learn.microsoft.com/en-us/xamarin/essentials/file-picker?tabs=android
UWP: https://learn.microsoft.com/en-us/windows/uwp/files/quickstart-save-a-file-with-a-picker