ios - 从另一个类调用时如何修复处理 PanGestureRecognizer 的错误？

Question

我想将 PanGestureRecognizer 添加到 UIViewController 的 UIView。我将 View 分成九个相等的部分，并由它们创建一个 UIViews。我还在每个部分添加了 PanGestureRocgnizer。当我在另一个需要它的类中调用它时，它工作正常，但是当我触摸屏幕的某个部分以启动 PangestureRecognizer 的句柄方法时，我得到错误: [UIView handlePanGestureRocognizer:]: 无法识别的选择器发送到实例 0x17de2ee0 .这是我的代码:

#import "CustomGestureRecognizer.h"

@implementation CustomGestureRecognizer
@synthesize arrayOfPatternsForComparison;
@synthesize arrayOfSubviews;
@synthesize arrayOfPanGestureRecognizers;



- (void)initialize:(UIView *)view {
    arrayOfPatternsForComparison = [[NSMutableArray alloc] init];
    arrayOfSubviews = [[NSMutableArray alloc] init];
    arrayOfPanGestureRecognizers = [[NSMutableArray alloc] init];

    [self createPatternsForComparison];
    [self splitScreenInParts:view];
    [self setPanGestrueRecognizersOnEveryPartOfTheScreen];
}

- (void)createPatternsForComparison {

}

- (void)splitScreenInParts:(UIView *)view {
    CGSize onePart = CGSizeMake(view.frame.size.width/3, view.frame.size.height/3);
    CGFloat x_positionOfPart = 0;
    CGFloat y_positionOfPart = 0;

    for (NSUInteger j=0; j<3; j++) {
        for (NSUInteger i=0; i<3; i++) {
            UIView *_view = [[UIView alloc] initWithFrame:CGRectMake(x_positionOfPart, y_positionOfPart, onePart.width, onePart.height)];

            [[_view layer] setBorderWidth:1.0];
            [[_view layer] setBorderColor:[UIColor redColor].CGColor];

            x_positionOfPart += onePart.width;
            [arrayOfSubviews addObject:_view];
            [view addSubview:_view];
        }
        y_positionOfPart += onePart.height;
        x_positionOfPart = 0;
    }

}

- (void)setPanGestrueRecognizersOnEveryPartOfTheScreen {
    for (UIView *view in arrayOfSubviews) {
        UIPanGestureRecognizer *panGestureRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:view action:@selector(handlePanGestureRocognizer:)];
        [[panGestureRecognizer view] setTag:[arrayOfSubviews indexOfObject:view]];
        [view addGestureRecognizer:panGestureRecognizer];
    }
}


- (void)handlePanGestureRocognizer:(UIPanGestureRecognizer *)sender {
    NSLog(@"%d", [[sender view] tag]);
}



@end

在另一类 UIViewController 我这样称呼它:

- (void)viewWillAppear:(BOOL)animated {
    CustomGestureRecognizer *cgr = [[CustomGestureRecognizer alloc] init];
    [cgr initialize:[self view]];
}

如何解决这个问题？感谢您的回答。

Answer 1

因为cgr当你调用它时被释放。

您必须创建一个 var CustomGestureRecognizer *cgr在 .h 中，然后:

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    cgr = [[CustomGestureRecognizer alloc] init];
    [cgr initialize:[self view]];
}

然后改变这一行

UIPanGestureRecognizer *panGestureRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:view action:@selector(handlePanGestureRocognizer:)];

到

UIPanGestureRecognizer *panGestureRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handlePanGestureRocognizer:)];