如果想监听一个view上面的触摸事件，不使用手势实现的步骤
(1). 自定义一个view
(2). 实现view的touches方法，在方法内部实现具体处理代码
通过touches方法监听view触摸事件，有很明显的几个缺点
(1). 必须得自定义view
(2). 由于是在view内部的touches方法中监听触摸事件，因此默认情况下，无法让其他外界对象监听view的触摸事件
(3). 不容易区分用户的具体手势行为
ios 3.2之后，苹果推出了手势识别功能（gesture recognizer），在触摸事件处理方面，大大简化了开发者的开发难度
为了完成手势识别，必须借助于手势识别器：uigesturerecognizer
利用uigesturerecognizer，能轻松识别用户在某个view上面做的一些常见手势
uigesturerecognizer是一个抽象类，定义了所有手势的基本行为，使用它的子类才能处理具体的手势
uigesturerecognizer的子类
uitapgesturerecognizer(敲击)
uipinchgesturerecognizer(捏合，用于缩放)
uipangesturerecognizer(拖拽)
uiswipegesturerecognizer(轻扫)
uirotationgesturerecognizer(旋转)
uilongpressgesturerecognizer(长按)
uigesturerecognizer继承于nsobject
// 初始化手势要触发的对象与事件 - (instancetype)initwithtarget:(nullable id)target action:(nullable sel)action // 添加手势要触发的对象与事件 - (void)addtarget:(id)target action:(sel)action; // 移除手势要触发的对象与事件 - (void)removetarget:(nullable id)target action:(nullable sel)action; // 手势状态 @property(nonatomic,readonly) uigesturerecognizerstate state; // 代理 @property(nullable,nonatomic,weak) id delegate; // 手势是否可用，默认yes @property(nonatomic, getter=isenabled) bool enabled; // 只读，手势所属的视图 @property(nullable, nonatomic,readonly) uiview *view; // 默认yes.意思就是说一旦手势被识别，那么就调用[touchview touchescancelled:withevent] @property(nonatomic) bool cancelstouchesinview; // 默认no.意思就是再手势识别成功之前，touchobj还是要分发到touchview. // 设置为yes的时候就表示从手势识别成功之前touchobj不给touchview分发 @property(nonatomic) bool delaystouchesbegan; // 默认yes:在手势识别成功之前，touchesended不会被调用。 // 设置为no:在手势识别成功之前，touchesended会被调用 @property(nonatomic) bool delaystouchesended; // 当指定的识别器(调用者)识别失败，才去识别另一个识别器othergesturerecognizer - (void)requiregesturerecognizertofail:(uigesturerecognizer *)othergesturerecognizer; // 获取手势识别器的触摸点 - (cgpoint)locationinview:(nullable uiview*)view; // 获取手势识别器的触摸点个数 - (nsuinteger)numberoftouches; // 指定触摸点的位置 - (cgpoint)locationoftouch:(nsuinteger)touchindex inview:(nullable uiview*)view;
注意： 使用多个手势必须使用代理
// 是否允许触发手势 - (bool)gesturerecognizershouldbegin:(uigesturerecognizer *)gesturerecognizer; // 是否允许多个同时支持多个手势，默认不允许，手势必须要设置代理 - (bool)gesturerecognizer:(uigesturerecognizer *)gesturerecognizer shouldrecognizesimultaneouslywithgesturerecognizer:(uigesturerecognizer *)othergesturerecognizer; // 这个方法在这两个gesture recognizers中的任意一个将堵塞另一个的触摸事件时调用， // 如果返回yes,则两个gesture recognizers可同时识别， // 如果返回no，则并不保证两个gesture recognizers必不能同时识别， // 因为另外一个gesture recognizer的此方法可能返回yes。 // 也就是说两个gesture recognizers的delegate方法只要任意一个返回yes，则这两个就可以同时识别； // 只有两个都返回no的时候，才是互斥的。默认情况下是返回no - (bool)gesturerecognizer:(uigesturerecognizer *)gesturerecognizer shouldrequirefailureofgesturerecognizer:(uigesturerecognizer *)othergesturerecognizer ns_available_ios(7_0); // 是否允许手势识别器识别失败的时候使用另一个识别器othergesturerecognizer - (bool)gesturerecognizer:(uigesturerecognizer *)gesturerecognizer shouldberequiredtofailbygesturerecognizer:(uigesturerecognizer *)othergesturerecognizer ns_available_ios(7_0); // 是否允许接收触摸点 - (bool)gesturerecognizer:(uigesturerecognizer *)gesturerecognizer shouldreceivetouch:(uitouch *)touch; // 是否允许接收长按点 - (bool)gesturerecognizer:(uigesturerecognizer *)gesturerecognizer shouldreceivepress:(uipress *)press;
// 需要连续敲击几次才可触发，默认1次 @property (nonatomic) nsuinteger numberoftapsrequired; // 需要几根手指一起敲击才可触发，默认1根 @property (nonatomic) nsuinteger numberoftouchesrequired __tvos_prohibited;
提示： 模拟器快捷键：opsin + shift 向上拖“两个触摸点”
// 缩放比例 @property (nonatomic) cgfloat scale; // 缩放速度 @property (nonatomic,readonly) cgfloat velocity;
// 拖动的最短距离 @property (nonatomic) nsuinteger minimumnumberoftouches __tvos_prohibited; // 拖动的最长距离 @property (nonatomic) nsuinteger maximumnumberoftouches __tvos_prohibited; // 在指定的view上得坐标 - (cgpoint)translationinview:(nullable uiview *)view; // 设置在view中移动以后的坐标为translation - (void)settranslation:(cgpoint)translation inview:(nullable uiview *)view; // 拖动view，返回的值就用于计算view相对于父控件拖动的速度 - (cgpoint)velocityinview:(nullable uiview *)view;
// 需要几根手指一起轻扫才可触发，默认1根 @property(nonatomic) nsuinteger numberoftouchesrequired __tvos_prohibited; // 设置轻扫方向 @property(nonatomic) uiswipegesturerecognizerdirection direction;
// 旋转角度 @property (nonatomic) cgfloat rotation; // 旋转速度 @property (nonatomic,readonly) cgfloat velocity;
注意： 长安手势一般会触发两次，所有一般为了只做一次，要做一次判断
// 需要连续长按几次才可触发，默认0次 @property (nonatomic) nsuinteger numberoftapsrequired; // 需要几根手指一起长按才可触发，默认1根 @property (nonatomic) nsuinteger numberoftouchesrequired __tvos_prohibited; // 最小长按时间 @property (nonatomic) cftimeinterval minimumpressduration; // 允许移动距离 @property (nonatomic) cgfloat allowablemovement;
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#import "viewcontroller.h"
@interface viewcontroller ()
@property (weak, nonatomic) iboutlet uiimageview *imageview;
@end
@implementation viewcontroller
- (void)viewdidload {
[super viewdidload];
// do any additional setup after loading the view, typically from a nib.
[self setuptap];
[self setuplongpress];
[self setupswipe];
[self setuprotation];
[self setuppinch];
[self setuppan];
}
#pragma mark - 点按手势
- (void)setuptap {
uitapgesturerecognizer *gesturerecognizer = [[uitapgesturerecognizer alloc] initwithtarget:self action:@selector(actionuptap)];
// 多个手势必须要代理
gesturerecognizer.delegate = self;
[_imageview addgesturerecognizer:gesturerecognizer];
}
- (void)actionuptap {
nslog(@"点按手势");
}
#pragma mark - 长按手势
- (void)setuplongpress {
uilongpressgesturerecognizer *gesturerecognizer = [[uilongpressgesturerecognizer alloc] initwithtarget:self action:@selector(actionlongpress)];
gesturerecognizer.delegate = self;
[_imageview addgesturerecognizer:gesturerecognizer];
}
- (void)actionlongpress {
nslog(@"长按手势");
}
#pragma mark - 轻扫手势
- (void)setupswipe{
// 默认向右轻扫，如果要同时有多个轻扫方向，必须要创建轻扫对象
uiswipegesturerecognizer *gesturerecognizerright = [[uiswipegesturerecognizer alloc] initwithtarget:self action:@selector(actionswipe)];
[_imageview addgesturerecognizer:gesturerecognizerright];
uiswipegesturerecognizer *gesturerecognizerleft = [[uiswipegesturerecognizer alloc] initwithtarget:self action:@selector(actionswipe)];
// 向左轻扫
gesturerecognizerleft.direction = uiswipegesturerecognizerdirectionleft;
[_imageview addgesturerecognizer:gesturerecognizerleft];
uiswipegesturerecognizer *gesturerecognizerup = [[uiswipegesturerecognizer alloc] initwithtarget:self action:@selector(actionswipe)];
// 向上轻扫
gesturerecognizerup.direction = uiswipegesturerecognizerdirectionup;
[_imageview addgesturerecognizer:gesturerecognizerup];
uiswipegesturerecognizer *gesturerecognizerdown = [[uiswipegesturerecognizer alloc] initwithtarget:self action:@selector(actionswipe)];
// 向下轻扫
gesturerecognizerdown.direction = uiswipegesturerecognizerdirectiondown;
[_imageview addgesturerecognizer:gesturerecognizerdown];
}
- (void)actionswipe {
nslog(@"轻扫手势");
}
#pragma mark - 旋转手势
- (void)setuprotation {
uirotationgesturerecognizer *gesturerecognizer = [[uirotationgesturerecognizer alloc] initwithtarget:self action:@selector(actionrotation:)];
gesturerecognizer.delegate = self;
[_imageview addgesturerecognizer:gesturerecognizer];
}
- (void)actionrotation:(uirotationgesturerecognizer *)rotation {
_imageview.transform = cgaffinetransformrotate(_imageview.transform, rotation.rotation);
// 复位
rotation.rotation = 0;
}
#pragma mark - 捏合手势
- (void) setuppinch {
uipinchgesturerecognizer *gesturerecognizer = [[uipinchgesturerecognizer alloc] initwithtarget:self action:@selector(actionpinch:)];
gesturerecognizer.delegate = self;
[_imageview addgesturerecognizer:gesturerecognizer];
}
- (void)actionpinch:(uipinchgesturerecognizer *)pinch {
_imageview.transform = cgaffinetransformscale(_imageview.transform, pinch.scale, pinch.scale);
// 复位
pinch.scale = 1;
}
#pragma mark - 拖拽手势
- (void)setuppan {
uipangesturerecognizer *gesturerecognizer = [[uipangesturerecognizer alloc] initwithtarget:self action:@selector(actionpan:)];
gesturerecognizer.delegate = self;
[_imageview addgesturerecognizer:gesturerecognizer];
}
- (void)actionpan:(uipangesturerecognizer *)pan {
//nslog(@"%ld",[pan numberoftouches]);
// 获取手势的触摸点
// cgpoint curp = [pan locationinview:self.imageview];
cgpoint pantrans = [pan translationinview:_imageview];
_imageview.transform = cgaffinetransformtranslate(_imageview.transform, pantrans.x, pantrans.y);
// 复位
[pan settranslation:cgpointzero inview:_imageview];
}
#pragma mark - 手势代理
// 是否允许多个同时支持多个手势，默认不允许，手势必须要设置代理
- (bool)gesturerecognizer:(uigesturerecognizer *)gesturerecognizer shouldrecognizesimultaneouslywithgesturerecognizer:(uigesturerecognizer *)othergesturerecognizer {
return yes;
}
// 是否允许触发手势事件
- (bool)gesturerecognizershouldbegin:(uigesturerecognizer *)gesturerecognizer {
return yes;
}
// 是否允许接收触摸点
- (bool)gesturerecognizer:(uigesturerecognizer *)gesturerecognizer shouldreceivetouch:(uitouch *)touch {
return yes;
}
@end
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