直接在controller里面加代码实现的抽屉效果
代码语言：javascript复制@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];
//把左侧边的view先隐藏
_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坐标位置
CGFloat Xresult = translation.x _leftView.frame.origin.x;
//向右
if (translation.x >= 0) {
//leftView已全部拉出，则无法再向右
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，则无法再向左
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;
//清空移动的距离，这是关键
[recognizer setTranslation:CGPointZero inView:recognizer.view];
//做弹回效果，以中轴为界限
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) {
}];
}</pre> 
