无法从touchesEnded发送参数

Question

我正在尝试从我的touchesEnded处理程序中发送一个参数，如下所示...

    - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {

    UITouch *touch = [touches anyObject];
    CGPoint currentPosition = [touch locationInView:self.view];
    CGFloat deltaX = fabsf(gestureStartPoint.x - currentPosition.x);
    CGFloat deltaY = fabsf(gestureStartPoint.y - currentPosition.y);
    if (deltaX >= 0.3 && deltaY <= 100) { //horizontal swipe detected

               [self performSelector:@selector(refreshCover:)
                   withObject:nil afterDelay:0];
        if (gestureStartPoint.x < currentPosition.x) { //swipe right
            [self refreshCover:@"backward"];
            NSLog(@"swipe backward");
        } else { //swipe left
            [self refreshCover:@"forward"];
            NSLog(@"swipe forward");
        }       
    }
}

然后在refreshCover中，我只需要：

    - (void)refreshCover:(NSString*)direction {

    NSLog(@"direction: %@", direction);
}

当用户滑动时，会调用refreshCover，但不会传递direction参数。如果我从其他任何地方调用self refreshCover:@"forward“，参数传递都没有问题。

有什么想法吗？提前谢谢。

Answer 1

问题出在下面的代码中

[self performSelector:@selector(refreshCover:)
               withObject:nil afterDelay:0];

performSelector将调用该函数。我认为这段代码是不需要的，因为您是单独调用该函数的