Proper approach on async/await method including Lambda

Proper approach on async/await method including Lambda

I would like to show two paradigms about async programming and listen to
your comments.
A.
Let's say you have created a method like the following in a library to use
it from your GUI clients.
public async Task<TestObject> DoSomeWork(string aParam1, object aParam2)
{
TestObject testObj = new TestObject();
...fill in params to testObj...
await MethodCallAsync(testObj);
....do other work synchronous.....
....continue fill testObj properties...
await Task.Delay(1000) // just a delay for no reason
...continue synchronous work.....
return testObj;
}
Ok, but this will chop my GUI context into small calling pieces, right? or
I don't know if from the moment you declare a method async it will create
a Task for all the operations inside?
If yes then great, no problem we can just declare it async and move on
with our lives.
Lets say no and I would like to take the following approach so I won't
disturb the GUI at all until my whole method call finishes and take the
result so do something in my calling method.
B.
Another approach would be.
public async Task<TestObject> DoSomeWork(string aParam1, object aParam2)
{
TestObject testObj = new TestObject()
..fill state params....
return await Task.Factory.StartNew((state) =>
{
//But now I need to do async/await in here
// is it a good practice to async await lambdas?
// async/await practices say it's ok as long sas it is not becoming
async void
// which in our case is not.
await MethodCallAsync(testObj);
....do other work synchronous.....
....continue fill state properties...
await Task.Delay(1000) // just a delay for no reason
...continue synchronous work.....
return state; // Our state and TestObject to examine after completion
}, testObj);
}
Our problem now it's not only if we should asyncify the lambda, say you do
it, it the will return a Task<Task<TestObject>> and definitely we don't
want that.
You should call this up in the pipeline, most probably your GUI class.
private async void SomethingClickedOrTouched(object sender, EventArgs e)
{
await RunThisAsyncToDoYourJob();
}
private async Task RunThisAsyncToDoYourJob()
{
TestObject testObj = await myObject.DoSomeWork("param1", anotherObject);
}
It just bugs me a little and I really want into detail with async
programming.
So, is A paradigm the correct approach anyway, and use the B paradigm only
when the Task lambda inside code is completely synchronous? Thank you in
advance.
Regards.