(Objective-C) Understanding Async Function Return Values

See more Async Examples

Explains how to get the return value of the function called synchonously in the background thread.

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#import <CkoSocket.h>
#import <CkoTask.h>
#import <NSString.h>

// Some Chilkat functions can be called asynchronously.
// If a function "Func" can be called asynchronously, there will be a corresponding "FuncAsync" function that returns a Task object.
// 
// When Task.Run is called, the synchronous "Func" runs in a background thread.
// 

// For Chilkat methods that return a status (YES/NO), get returned value by calling GetResultBool.
// For example..

CkoSocket *sock = [[CkoSocket alloc] init];

// --------------------------------------------------------------
// Synchronous call returning YES/NO
BOOL success = [sock Connect: @"example.com" port: [NSNumber numberWithInt: 443] ssl: YES maxWaitMs: [NSNumber numberWithInt: 5000]];

// --------------------------------------------------------------
// Asynchronous call
CkoTask *task = [sock ConnectAsync: @"example.com" port: [NSNumber numberWithInt: 443] ssl: YES maxWaitMs: [NSNumber numberWithInt: 5000]];
// ...
[task Run];
// ...
// ...
// Get the status (YES/NO) value returned by the synchronous method called in the background thread.
success = [task GetResultBool];

// --------------------------------------------------------------
// Synchronous call returning an integer
int count = [[sock ReceiveCount] intValue];

// --------------------------------------------------------------
// Asynchronous call
task = [sock ReceiveCountAsync];
// ...
[task Run];
// ...
// ...
// Get the integer value returned by the synchronous method called in the background thread.
count = [[task GetResultInt] intValue];

// --------------------------------------------------------------
// Synchronous call returning an string
NSString *s = [sock ReceiveString];

// --------------------------------------------------------------
// Asynchronous call
task = [sock ReceiveStringAsync];
// ...
[task Run];
// ...
// ...
// Get the string value returned by the synchronous method called in the background thread.
s = [task GetResultString];

// --------------------------------------------------------------
// Synchronous call returning an object
CkoSocket *connection = [sock AcceptNextConnection: [NSNumber numberWithInt: 5000]];

// --------------------------------------------------------------
// Asynchronous call
task = [sock AcceptNextConnectionAsync];
// ...
[task Run];
// ...
// ...
// Get the object returned by the synchronous method called in the background thread.
// We do this a little differently.  We create an new object of the same type,
// and then load it with the returned object (assuming it was not null).
CkoSocket *acceptedConnection = [[CkoSocket alloc] init];
if (task.TaskSuccess == YES) {
    success = [acceptedConnection LoadTaskResult: task];
}