What would be the equivalent of doing this with NSOperation?

Question

[self performSelector:@selector(stopPulling) withObject:nil afterDelay:0.01];

The code is fine. I just think that using NSOperation and block should be the way to go for the future.

I am familiar with NSOperation. I just want to do the same thing with block and NSOperation.

I can do this with GCD already:

int64_t delayInSeconds = 2.0;
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, delayInSeconds * NSEC_PER_SEC);
dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
    <#code to be executed on the main queue after delay#>
});

C'mon. There is something that can be done in GCD that can't be done more easily in NSOperation?

score 1 · Answer 1 · edited May 23 '17 at 12:21

I ended up making this:

#import "BGPerformDelayedBlock.h"

@implementation BGPerformDelayedBlock


+ (void)performDelayedBlock:(void (^)(void))block afterDelay:(NSTimeInterval)delay
{
    int64_t delta = (int64_t)(1.0e9 * delay);
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, delta), dispatch_get_main_queue(), block);
}

+(void)performSlightlyDelayedBlock:(void (^)(void))block
{
    [self performDelayedBlock:block afterDelay:.1];
}
@end

It's based on an answer in How do you trigger a block after a delay, like -performSelector:withObject:afterDelay:?

I think it shouldn't be a category.

Strange that I ended up using GCD.

However, using it is simple. I just do:

    [BGPerformDelayedBlock performSlightlyDelayedBlock:^{
        [UIView animateWithDuration:.3 animations:^{
            [self snapToTheTopOfTheNonHeaderView];
        }];
    }];

score 1 · Accepted Answer · answered Oct 25 '12 at 05:36

1

NSOperationQueue does not provide a mechanism for delayed execution. Use GCD or NSTimer.

answered Oct 25 '12 at 05:36

Catfish_Man

41,261
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score 0 · Answer 3 · answered Oct 23 '12 at 06:31

0

Your code is similar to, using a NSTimer setting a selector after 0.01sec with no repeats. This will be called on the main thread.

NSOperation or blocks are used to perform operations in background. These you can use instead of performSelectorInBackground.

If your need is to work in background then go for it. There are many tutorials available to learn 'NSOperationusing 'NSOperationQueue and blocks.

answered Oct 23 '12 at 06:31

vishy

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I already use tons of NSOperationQueue. [NSOperationQueue MainQueue] addoperationwithblock, for example will sort of work too. But I need delay. I want solution with blocks rather than selector. – Anonymous White Oct 23 '12 at 08:03

What would be the equivalent of doing this with NSOperation?

3 Answers3