@interface ViewController () { UIView* _leftView;} @end @implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib.  _leftView = [[UIView alloc] init]; //把左側邊的view先隱藏 _leftView.frame = CGRectMake(-200, 0, 200, self.view.frame.size.height); _leftView.backgroundColor = [UIColor greenColor]; [self.view addSubview:_leftView];  UIPanGestureRecognizer* pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handlePan:)]; [self.view addGestureRecognizer:pan];} - (void)handlePan:(UIPanGestureRecognizer*) recognizer { CGPoint translation = [recognizer translationInView:self.view]; //增量后的x坐標位置 CGFloat Xresult = translation.x + _leftView.frame.origin.x;  //向右 if (translation.x >= 0) { //leftView已全部拉出，則無法再向右 if (_leftView.frame.origin.x >= 0 || Xresult >= 0) {  _leftView.frame = CGRectMake(0, 0, 200, self.view.frame.size.height);    return; } } else if (translation.x < 0) {//向左 //leftView已全部收回，則無法再向左 if (_leftView.frame.origin.x <= -200 || Xresult <= -200) {  _leftView.frame = CGRectMake(-200, 0, 200, self.view.frame.size.height);  return; } }  CGRect frame = _leftView.frame; frame.origin.x += translation.x; _leftView.frame = frame;  //清空移動的距離，這是關鍵 [recognizer setTranslation:CGPointZero inView:recognizer.view];  //做彈回效果，以中軸為界限 if (recognizer.state == UIGestureRecognizerStateEnded) { if (_leftView.frame.origin.x > -100) {  [self closeView:NO]; } else {  [self closeView:YES]; } }} - (void)closeView:(BOOL)close { if (close) { [self moveView:CGRectMake(-200, 0, 200, self.view.frame.size.height)]; } else { [self moveView:CGRectMake(0, 0, 200, self.view.frame.size.height)]; }} - (void)moveView:(CGRect)frame { [UIView animateWithDuration:0.3 animations:^{ _leftView.frame = frame; } completion:^(BOOL finished) {   }];}

#import "PathView.h"#import "UIView+Additions.h" @implementation PathView - (instancetype)init { self = [super init]; if (self) { [self setupGestureRecognizer]; } return self;} - (void)setupGestureRecognizer { UIPanGestureRecognizer* pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handlePan:)]; [self addGestureRecognizer:pan];} - (void)handlePan:(UIPanGestureRecognizer*)recognizer { CGPoint translation = [recognizer translationInView:self];  CGFloat Xresult = translation.x + self.left;  if (translation.x >= 0) {//向右 if (self.left >= _leftWidth || Xresult >= _leftWidth) {  self.frame = CGRectMake(_leftWidth, 0, self.width, self.height);  return; } } else if (translation.x < 0) {//向左 if (self.left <= -_rightWidth || Xresult <= -_rightWidth) {  self.frame = CGRectMake(-_rightWidth, 0, self.width, self.height);  return; } }  self.left += translation.x;  if (recognizer.state == UIGestureRecognizerStateEnded) { if (self.left > _leftWidth / 2) {  [self openLeft:YES openRight:NO]; }   else if (self.left < -(_rightWidth / 2)) {  [self openLeft:NO openRight:YES]; }   else {  [self openLeft:NO openRight:NO]; } }  //清空移動的距離 [recognizer setTranslation:CGPointZero inView:recognizer.view];} - (void)openLeft:(BOOL)left openRight:(BOOL)right { if (!left && !right) { [self moveView:CGRectMake(0, 0, self.width, self.height)];   } else if (!left && right) { [self moveView:CGRectMake(-_rightWidth, 0, self.width, self.height)];   } else if (left && !right) { [self moveView:CGRectMake(_leftWidth, 0, self.width, self.height)];   }} - (void)moveView:(CGRect)frame { [UIView animateWithDuration:0.3 animations:^{ self.frame = frame; } completion:^(BOOL finished) {   }];}