DispatchQueue.main.async and OperationQueue.main.addOperation not same?

Asked Jun 30 '17 at 14:15

Active Jun 30 '17 at 14:44

Viewed 694 times

I use swift 3 & xcode8

My code is below

[A]

DispatchQueue(label: "background").async {
            autoreleasepool {

             *DB UPDATE CODE HERE  
            }

            OperationQueue.main.addOperation {
                self.uiUpdate() <-- data query & UI update code   
                self.ResultTable.reloadData() <-- tableview reload 
            }

        }

[B]

 DispatchQueue(label: "background").async {
        autoreleasepool {

         *DB UPDATE CODE HERE  
        }

        DispatchQueue.main.async {
            self.uiUpdate() <-- [C] some data query & UI update code   
            self.ResultTable.reloadData() <-- [D]tableview reload 
        }

    }

[A] code is works very well.

but [B] is something wrong

if i execute [B] 5 times

C is works good but sometimes UI is not updated

I heard that OperationQueue.main.addOperation and DispatchQueue.main.async

is same but works differently

I dont understand ,,Diffrence A and B

edited Jun 30 '17 at 14:44

asked Jun 30 '17 at 14:15

ttoggaiman

1

Your title doesn't match your question. – rmaddy Jun 30 '17 at 14:17
ok! sorry i updated subject – ttoggaiman Jun 30 '17 at 14:44
did you noticed in [b] your both operations are async and in [a] you have two queue main and background async. in [b] data ui updates are not sync with the DB UPDATE CODE well in [a] they are. – iOS Geek Jul 01 '17 at 05:14

DispatchQueue.main.async and OperationQueue.main.addOperation not same?

0 Answers0