Question

我已经整合了一个UIView，其中包含完全在其自己的实现代码中的平移，捏合和旋转手势识别器，因此它可以在任何视图控制器中工作，即使是一个零代码（除了关闭Xcode中的自动布局。

#import "Subview.h"

@interface Subview () <UIGestureRecognizerDelegate>

@end

@implementation Subview

- (void)awakeFromNib
{
    [self addGestureRecognizer:[[UIRotationGestureRecognizer alloc]initWithTarget:self action:@selector(rotateView:)]];
    [self addGestureRecognizer:[[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(panView:)]];
    [self addGestureRecognizer:[[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(pinchView:)]];

    for (UIGestureRecognizer * gr in self.gestureRecognizers){
        gr.delegate = self;
    }
}

// delegate method:
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
    return YES;
}

// gesture actions:
- (void)rotateView:(UIRotationGestureRecognizer *)sender
{
    [self adjustAnchorPointForGestureRecognizer:sender];

    if (sender.state == UIGestureRecognizerStateBegan || sender.state == UIGestureRecognizerStateChanged) {
        self.transform = CGAffineTransformRotate(self.transform, sender.rotation);
        sender.rotation = 0;
    }

}

- (void)panView:(UIPanGestureRecognizer *)sender
{
    [self adjustAnchorPointForGestureRecognizer:sender];

    if (sender.state == UIGestureRecognizerStateBegan || sender.state == UIGestureRecognizerStateChanged) {
        CGPoint translation = [sender translationInView:self.superview];
        [self setCenter:CGPointMake(self.center.x + translation.x, self.center.y + translation.y)];
        [sender setTranslation:CGPointZero inView:self.superview];
    }
}

- (void)pinchView:(UIPinchGestureRecognizer *)sender
{
    [self adjustAnchorPointForGestureRecognizer:sender];

    if (sender.state == UIGestureRecognizerStateBegan || sender.state == UIGestureRecognizerStateChanged) {
        sender.view.transform = CGAffineTransformScale(sender.view.transform, sender.scale, sender.scale);
        sender.scale = 1.0;
    }
}

- (void)adjustAnchorPointForGestureRecognizer:(UIGestureRecognizer *)sender
{
    if (sender.state == UIGestureRecognizerStateBegan) {
        CGPoint locationInView = [sender locationInView:self];
        CGPoint locationInSuperview = [sender locationInView:self.superview];

        self.layer.anchorPoint = CGPointMake(locationInView.x / self.bounds.size.width, locationInView.y / self.bounds.size.height);
        self.center = locationInSuperview;
    }
}

@end

到目前为止它工作得很好并且编译器没有给出警告，但是我不确定视图是否设置了自己的框架和中心，并且是自己的委托。但它确实有助于清理视图控制器，并且感觉非常整洁和便携。那么这实际上是否会导致任何微妙的错误或违反任何最佳实践规则？

UIView具有自包含的UIGestureRecognizer代码

0 个答案: