iOS抽屉效果开发案例分享

#import "ViewController.h"
 
@interface ViewController ()
@property(nonatomic, weak) UIView *mainV;
@property(nonatomic, weak) UIView *leftV;
@property(nonatomic, weak) UIView *rightV;
@end

#pragma mark - 添加子控件
- (void)setUpChildViews {
   
  UIView *leftV = [[UIView alloc]initWithFrame:self.view.bounds];
   
  leftV.backgroundColor = [UIColor orangeColor];
   
  [self.view addSubview:leftV];
   
  _leftV = leftV;
   
  UIView *rightV = [[UIView alloc]initWithFrame:self.view.bounds];
   
  rightV.backgroundColor = [UIColor groupTableViewBackgroundColor];
   
  [self.view addSubview:rightV];
   
  _rightV = rightV;
   
  UIView *mainV = [[UIView alloc]initWithFrame:self.view.bounds];
   
  mainV.backgroundColor = [UIColor yellowColor];
   
  [self.view addSubview:mainV];
   
  _mainV = mainV;
}
 
- (void)viewDidLoad {
  [super viewDidLoad];
   
  //添加子控件
  [self setUpChildViews];
   
  //添加Pan手势
  UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(pan:)];
   
  [self.view addGestureRecognizer:pan];
   
  //添加点按手势，在主视图上任意位置点击回到屏幕开始位置
  UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(tap)];
   
  [self.view addGestureRecognizer:tap];
   
}

#pragma mark - 手势识别方法
#define targetL -230
#define targetR 200
#define screenW [UIScreen mainScreen].bounds.size.width
- (void)pan:(UIPanGestureRecognizer *)pan {
   
  //获取手势移动的位置
  CGPoint tranP = [pan translationInView:self.view];
   
  //获取x的偏移量
  CGFloat offsetX = tranP.x;
   
  //修改mainV的frame
  _mainV.frame = [self frameWithOffsetX:offsetX];
   
  //判断mainV的x是否大于0
  [self observeValueForKeyPath:nil ofObject:nil change:nil context:nil];
   
  //复位
  [pan setTranslation:CGPointZero inView:self.view];
   
  //判断当手势结束的时候，定位
  if (pan.state == UIGestureRecognizerStateEnded) {
     
    CGFloat target = 0;
     
    if (_mainV.frame.origin.x > screenW * 0.5) {
      //定位到右边
      target = targetR;
    }else if(CGRectGetMaxX(_mainV.frame) < screenW * 0.5) {
      //定位到左边
      target = targetL;
    }
     
    //获取X轴需要移动的偏移量
    CGFloat offsetX = target - _mainV.frame.origin.x;
     
    [UIView animateWithDuration:0.25 animations:^{
       
      _mainV.frame = target == 0 ? self.view.bounds : [self frameWithOffsetX:offsetX];
 
    }];
     
  }
   
}

- (void)tap {
   
  [UIView animateWithDuration:0.25 animations:^{
    _mainV.frame = self.view.bounds;
  }];
   
}

#define kMaxY 80
#pragma mark - 根据offsetX计算mainV的frame
- (CGRect)frameWithOffsetX:(CGFloat)offsetX {
   
  //获取上一次的frame
  CGRect frame = _mainV.frame;
   
  //获取屏幕的高度
  CGFloat screenH = [UIScreen mainScreen].bounds.size.height;
   
  //获取屏幕的宽度
  //CGFloat screenW = [UIScreen mainScreen].bounds.size.width;
   
  //X轴平移一点对应Y轴需要平移的距离
  CGFloat offsetY = offsetX * kMaxY / screenW;
   
  //获取上一次的高度
  CGFloat preH = frame.size.height;
   
  //获取上一次的宽度
  CGFloat preW = frame.size.width;
   
  //获取当前高度
  CGFloat curH = preH - 2 * offsetY;
  //如果是向左滑动
  if(frame.origin.x < 0) {
    curH = preH + 2 * offsetY;
  }
   
  //获取尺寸的缩放比例
  CGFloat scale = curH / preH;
   
  //获取当前宽度
  CGFloat curW = preW * scale;
   
  //获取当前x
  frame.origin.x += offsetX;
   
  //获取当前y
  CGFloat y = (screenH - curH) / 2;
  frame.origin.y = y;
   
  frame.size.width = curW;
  frame.size.height = curH;
   
  return frame;
   
}

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSString *,id> *)change context:(void *)context {
   
  if(_mainV.frame.origin.x > 0) {//往右边滑动
    _rightV.hidden = YES;
  }else if(_mainV.frame.origin.x < 0) {//往左边滑动
    _rightV.hidden = NO;
  }
   
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
 
  return 30;
}
 
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
   
   
  static NSString *ID = @"cell";
   
  UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:ID];
   
  if(cell == nil) {
    cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:ID];
  }
   
  cell.textLabel.text = [NSString stringWithFormat:@"第%ld行", indexPath.row];
   
  return cell;
}

- (void)viewDidLoad {
  [super viewDidLoad];
   
  XXViewController *vc = [[XXViewController alloc]init];
  vc.view.frame = self.view.bounds;
   
  //让vc成为主视图控制器的子控制器
  [self addChildViewController:vc];
   
  //主视图展示tableView
  [self.mainV addSubview:vc.view];
   
}

#import <UIKit/UIKit.h>
 
@interface ViewController : UIViewController
@property(nonatomic, weak, readonly) UIView *mainV;
@property(nonatomic, weak, readonly) UIView *leftV;
@property(nonatomic, weak, readonly) UIView *rightV;
@end