为异步C＃.net编写回调函数

Question

I am using Kinvey for my storage

The callback for a non Async function is written as shown

myClient.User().create(myUserName, myPassword, new KinveyUserCallback(){...});

how do i do it if I was using an Async function ?

myClient.User().createAsync(myUserName, myPassword);

Im interested in the onError callback to check if the user already exists.

Answer 1

In kinvey's documentation, they clearly stated that:

If the username does exist, the callback's onError method will be invoked

So when you execute this code:

User user = await myClient.User().createAsync(myUserName, myPassword);

if the user already exists , you will receive the error message inside onError function as below.

@Override
public void onError(String error) {
     // do something with the error
     // maybe log it and/or throw the error to UI
}