1、监听手势滑动的方法
1-1、监听手势开始接触屏幕方法
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
1-2、监听手势在屏幕上滑动方法
- (void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
1-3、监听手势滑动结束
- (void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
2、完整Demo
2-1：通过手势的滑动来改变背景颜色的 alpha值
//
// ViewController.m
// 66-手势滑动
//
// Created by freedom on 16/10/17.
// Copyright © 2016年 Raven. All rights reserved.
//
#import "ViewController.h"
@interface ViewController ()
/**
* 第一个点
*/
@property (nonatomic, assign) CGPoint firstPoint;
/**
* 第二个点
*/
@property (nonatomic, assign) CGPoint secondPoint;
/**
* 最开始的点
*/
@property (nonatomic, assign) CGPoint startPoint;
/**
* 滚动条
*/
@property (nonatomic, strong) UISlider *alider;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
CGFloat w = self.view.frame.size.width;
CGFloat h = self.view.frame.size.height;
UIView *blueView = [[UIView alloc] initWithFrame:CGRectMake(w-100, 100, 100, 100)];
blueView.backgroundColor = [UIColor blueColor];
[self.view addSubview:blueView];
self.alider = [[UISlider alloc] initWithFrame:CGRectMake(0, 100, w-300, h)];
self.alider.minimumValue = 0.0;
self.alider.maximumValue = 1.0;
self.alider.hidden = NO;
self.alider.value = [UIScreen mainScreen].brightness;
[self.view addSubview:self.alider];
}
#pragma mark -
#pragma mark 监听手势方法
#pragma mark 1-开始接触屏幕
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
//第一个点
for (UITouch *touch in event.allTouches) {
self.firstPoint = [touch locationInView:self.view];
}
self.startPoint = self.firstPoint;
}
#pragma mark 2-手势在屏幕上滑动
- (void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
//第二个点
for (UITouch *touch in event.allTouches) {
self.secondPoint = [touch locationInView:self.view];
}
self.alider.value += (self.firstPoint.y - self.secondPoint.y) / 500;
NSLog(@"%f", self.alider.value);
self.view.backgroundColor = [UIColor colorWithRed:self.alider.value green:0.0 blue:0.0 alpha:1.0];
self.firstPoint = self.secondPoint;
}
#pragma mark 3-手势在屏幕上滑动结束
- (void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
self.firstPoint = self.secondPoint = CGPointZero;
}
@end
3、小结
3-1、之所以使用UISlider是因为UISlider的值是从0~1来变化的，所以个人觉得，如果以后有什么需要线性变化都可以使用UISlider
3-2、演示时发现，如果UISlider显示出来（具有frame、hidden=NO）时，会发现具有UISlider区域的上面下面就不会具有滑动时间，所以建议隐藏UISlider
