App registration, often encounter the function of sending verification code, when the click to send the verification code, the button began the countdown, when the timing is over can be resend, the effect is as follows:
The specific code implementation is as follows:
-(Ibaction) Sendmes: (UIButton *) sender {__block int timeout = 10;//countdown time dispatch_queue_t queue = Dispatch_get_gl
Obal_queue (dispatch_queue_priority_default, 0);
dispatch_source_t _timer = dispatch_source_create (dispatch_source_type_timer, 0, 0,queue); Dispatch_source_set_timer (_timer, Dispatch_walltime (NULL, 0), 1.0 * nsec_per_sec, 0); Execution of Dispatch_source_set_event_handler (_timer, ^{/sec callback per second is the same as Nstimer execution method if (timeout<=0) {//Countdown end, Close di
Spatch_source_cancel (_timer); Dispatch_async (Dispatch_get_main_queue (), ^{//SET interface button display [sender settitle:@ "Send authentication Code" Forstate:uicontrolstatenormal
];
sender.enabled = YES;
});
}else{int seconds = timeout% 60;
NSString *strtime = [NSString stringwithformat:@ "%d", seconds];
Dispatch_async (Dispatch_get_main_queue (), ^{NSLog (@ "----%@", [Nsthread CurrentThread]); Set the button for the interface to display [sender settitle:[nsstring stringwithformat:@ "(%@) Retrieve", Strtime] Forstate:uicontrolstatedisabLED];
sender.enabled = NO;
});
timeout--;
}
});
Be sure to call the resume to turn on the timer function}
This button can be implemented directly in the storyboard, the background color of the button is selected to be gray, and then a background image is set, as in the red picture above, the button's type is set to:custom
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