子视图并不响应 tap 点击触摸手势 , 而是至于父视图响应 tap 触摸手势的效果 , 精确定位触摸的位置:
手势触摸位置识别
1.从代理方法能否开始过滤手势触摸的位置:
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer;
2.从手势能否进入 Possible 状态就开始过滤手势触摸的位置:
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch;
//
// GestureConditionViewController.m
// 15-手势实践
//
// Created by miaodong on 2017/6/19.
// Copyright © 2017年 miaodong. All rights reserved.
//
#import "GestureConditionViewController.h"
@interface GestureConditionViewController () <UIGestureRecognizerDelegate> {
UIView *_superView;
UIView *_subView;
UITapGestureRecognizer *_tap;
}
@end
@implementation GestureConditionViewController
#pragma mark - life Cycle
- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];
self.edgesForExtendedLayout = UIRectEdgeNone;
_superView = [[UIView alloc] initWithFrame:CGRectMake(50, 50, 200, 200)];
_superView.backgroundColor = [UIColor lightGrayColor];
[self.view addSubview:_superView];
_subView = [[UIView alloc] initWithFrame:CGRectMake(20, 20, 100, 100)];
_subView.backgroundColor = [UIColor orangeColor];
[_superView addSubview:_subView];
_tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tap:)];
_tap.delegate = self;
[_superView addGestureRecognizer:_tap];
}
#pragma mark - 手势方法
- (void)tap:(UITapGestureRecognizer *)tapGesture {
[self alertMessage:@"tap"];
}
- (void)alertMessage:(NSString *)message {
UIAlertController *alertVC = [UIAlertController alertControllerWithTitle:@"AlertVC" message:message preferredStyle:UIAlertControllerStyleAlert];
[alertVC addAction:[UIAlertAction actionWithTitle:@"确定" style: UIAlertActionStyleCancel handler:nil]];
[self presentViewController:alertVC animated:YES completion:nil];
}
//方法一:
#pragma mark - <UIGestureRecognizerDelegate>
//让父视图响应这个 tap 手势,子视图不响应这个手势:
//- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer {
// if (gestureRecognizer == _tap) {
// CGPoint location = [gestureRecognizer locationInView:_superView];
// //如果在第一个参数方块里包含了第二个参数的点坐标:
// if (CGRectContainsPoint(_subView.frame, location)) {
// return NO;
// }
// return YES;
// }
// return YES;
//}
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
{
if (gestureRecognizer == _tap) {
//如果触摸位置所在的视图不是父视图 , 并且 触摸位置所在的视图是父视图的子孙视图:
// if (touch.view != _superView && [touch.view isDescendantOfView:_superView]) {
// //那么就不响应手势:
// return NO;
// }
//用下面这种判断也是可以的~因为子视图是添加到父视图上的,触摸点击子视图位置的时候是 摸不到 父视图上的点的!
if (!(touch.view == _superView)) {
return NO;
}
return YES;
}
return YES;
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
}
@end
