串行分派队列中的块未执行-GCD iOS Objective-C

Question

I've got a for loop enqueuing blocks on to the main queue as follows:

  for (int x=0; x<5; x++) {
    double delayInSeconds = x * .03;
      dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, delayInSeconds * NSEC_PER_SEC);
      dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
        ... code here ...
      }
  }

Only the first block gets executed. I've verified that the loop is working properly, it is looping the proper number of times and no exceptions or error are raised.

Answer 1

With this code:

for (int x=0; x<5; x++) {
    double delayInSeconds = x * .03;
    dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, delayInSeconds * NSEC_PER_SEC);
    dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
        NSLog(@"Blah!!");
    });
}

"Blah" gets logged out 5 times. I'm guessing the code you posted isn't identical to the code you have in the app? I had to add the ); to the end of the dispatch_after call.