入住時間差調用的Objective-C

Question

我有這樣的方法：

- (void) receivedData { 
} 

這應該運行約每50至100毫秒。有沒有辦法檢查自上次調用以來的時間，並將最後一次打印到NSString？

Answer 1

@interface MyClass() { 
    NSDate* receivedDataTimestamp; 
    .... 
} 

... 

-(void)receivedData { 
    NSDate* now = [NSDate date]; 
    if (receivedDataTimestamp != nil) { 
     NSTimeInterval delta = [now timeIntervalSinceDate:receivedDataTimestamp]; 
     NSLog(@"%f seconds since recevedData was called last", delta); 
    } 
    receivedDataTimestamp = now; 
    .... 
}