CODEWITHSUNDEEP
c#asynchronous
Legends
Legends

Reputation: 22672

How to wrap result of an async method

How can I wrap the result of an async method into a my own wrapper class (MyEnvelop) and return it like a task?

I use a custom Envelope class for returning results from my Data Access component back to Business Layer. This works fine with sync methods, but how can I return the result of type MyEnvelope in async mode?

Updated the code sample:

  public async Task<MyEnvelope<Customer>> FindAsync(params object[] keyValues)
    {
        using (var nw = new NWRepository())
        {
        Customer result = await  nw.DoSomethingAsync<Customer>(keyValues);
        return // here I would like to return new MyEnvelope<Customer>(result)
               // wrapped in Task as shown in the signature
                }
            }

Upvotes: 0

Views: 760

Answers (2)

jimSampica
jimSampica

Reputation: 12410

Can't be done because you need the task to resolve before you can pass it to MyEnvelope. The closest you can get is to remove the async/await keywords which unwrap the task and get Task<Customer>.

public Task<Customer> FindAsync(params object[] keyValues)
{
    using (var nw = new NWRepository())
    {
        return nw.DoSomethingAsync<Customer>(keyValues)
    }
}

Upvotes: 0

Mihail Shishkov
Mihail Shishkov

Reputation: 15797

What you want to do is that:

public async Task<MyEnvelope<Customer>> FindAsync(params object[] keyValues)
{
    using (var nw = new NWRepository())
    {
         Customer c = await  nw.FindAsync<Customer>(keyValues);
          return new MyEnvelope<Customer>(c);
    }
 }

you then call the method like that:

MyEnvelope<Customer> customer = await FindAsync(p1, p2, p3);

Remember await will return the Result of a Task<T> which is of type T not the Task object itself.

Upvotes: 3

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