DirectionPanGestureRecognizer 专门识别竖向或者横向的拖动

DirectionPanGestureRecognizer.h

#import <UIKit/UIKit.h>
#import <UIKit/UIGestureRecognizerSubclass.h>

typedef enum {
    DirectionPangestureRecognizerVertical,
    DirectionPanGestureRecognizerHorizontal
} DirectionPangestureRecognizerDirection;

@interface DirectionPanGestureRecognizer : UIPanGestureRecognizer

@property (nonatomic, assign) DirectionPangestureRecognizerDirection direction;
@property (assign, nonatomic) BOOL hadRecognizer;

@end

DirectionPanGestureRecognizer.m

#import "DirectionPanGestureRecognizer.h"

@interface DirectionPanGestureRecognizer ()
@end

@implementation DirectionPanGestureRecognizer

@synthesize direction = _direction;

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    [super touchesMoved:touches withEvent:event];
    if (self.state == UIGestureRecognizerStateFailed) return;
    if (self.hadRecognizer == YES) {
        return;
    }
    CGPoint nowPoint = [[touches anyObject] locationInView:self.view];
    CGPoint prevPoint = [[touches anyObject] previousLocationInView:self.view];
    CGFloat moveX = prevPoint.x - nowPoint.x;
    CGFloat moveY = prevPoint.y - nowPoint.y;
    if (self.direction == DirectionPangestureRecognizerVertical) {
        if (fabs(moveX) > fabs(moveY)) {
            self.state = UIGestureRecognizerStateFailed;
        } else if(fabs(moveY) > fabs(moveX)) {
            self.hadRecognizer = YES;
        }
    } else {
        if (fabs(moveX) < fabs(moveY)) {
            self.state = UIGestureRecognizerStateFailed;
        } else if(fabs(moveY) < fabs(moveX)) {
            self.hadRecognizer = YES;
        }
    }

}

- (void)reset {
    [super reset];
    self.hadRecognizer = NO;
}

@end

use.md

    #import "DirectionPanGestureRecognizer.h"
    
    ...
    
    DirectionPanGestureRecognizer *verticalPanGestReco = [[DirectionPanGestureRecognizer alloc] initWithTarget:self action:@selector(panG:)];
    verticalPanGestReco.direction = DirectionPangestureRecognizerVertical;
    [self addGestureRecognizer:verticalPanGestReco];
    
    #pragma mark - 竖向手势识别
    - (void)panG:(DirectionPanGestureRecognizer*)gR
    {
            switch (gR.state) {
                    case UIGestureRecognizerStateBegan:
            
                            break;
                    case UIGestureRecognizerStateChanged:
                            if (gR.hadRecognizer) {
                                    // ...
                            }
                            break;
                    case UIGestureRecognizerStateEnded:
                            break;
                    default:
                            break;
            }
    }