******HMDrawViewController.m
#import "HMDrawViewController.h" @interface HMDrawViewController () @property (nonatomic, assign) BOOL isDraging;
@end @implementation HMDrawViewController - (void)viewDidLoad
{
// UIViewController
[super viewDidLoad];
// Do any additional setup after loading the view. // 1.添加子控件
[self addChildView];
#warning 第三步 观察_mainView的frame改变
// 2.监听
/**
* 给_mainView添加一个观察者
*
* KeyPath：监听frame这个属性
*
* options：监听新值的改变
*/
[_mainView addObserver:self forKeyPath:@"frame" options:NSKeyValueObservingOptionNew context:nil]; } // 当_mainView的frame属性改变的时候就会调用
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
NSLog(@"%@", NSStringFromCGRect(_mainView.frame)); if (_mainView.frame.origin.x < ) { // 往左移动
// 显示右边
_rightView.hidden = NO;
// 隐藏左边
_leftView.hidden = YES;
}else if (_mainView.frame.origin.x > ){ // 往右移动
// 显示左边
_rightView.hidden = YES;
// 隐藏右边
_leftView.hidden = NO; }
} #warning 第一步
- (void)addChildView
{
// left
UIView *leftView = [[UIView alloc] initWithFrame:self.view.bounds];
leftView.backgroundColor = [UIColor greenColor];
[self.view addSubview:leftView];
_leftView = leftView; // right
UIView *rightView = [[UIView alloc] initWithFrame:self.view.bounds];
rightView.backgroundColor = [UIColor blueColor];
[self.view addSubview:rightView];
_rightView = rightView; // mainView
UIView *mainView = [[UIView alloc] initWithFrame:self.view.bounds];
mainView.backgroundColor = [UIColor redColor];
[self.view addSubview:mainView];
_mainView = mainView;
} #warning 第二布
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
// 获取UITouch对象
UITouch *touch = [touches anyObject]; // 获取当前点
CGPoint currentPoint = [touch locationInView:self.view]; // 获取上一个点
CGPoint prePoint = [touch previousLocationInView:self.view]; // x轴偏移量：当手指移动一点的时候，x偏移多少
CGFloat offsetX = currentPoint.x - prePoint.x; // 设置当前主视图的frame
_mainView.frame = [self getCurrentFrameWithOffsetX:offsetX]; _isDraging = YES;
}
#warning 第四步
#define HMMaxY 60
// 当手指偏移一点，根据X轴的偏移量算出当前主视图的frame
- (CGRect)getCurrentFrameWithOffsetX:(CGFloat)offsetX
{
CGFloat screenW = [UIScreen mainScreen].bounds.size.width;
CGFloat screenH = [UIScreen mainScreen].bounds.size.height; // 获取y轴偏移量，手指每移动一点，y轴偏移多少
CGFloat offsetY = offsetX * HMMaxY / screenW; CGFloat scale = (screenH - * offsetY) / screenH; if (_mainView.frame.origin.x < ) { // 往左边滑动
scale = (screenH + * offsetY) / screenH;
} // 获取之前的frame
CGRect frame = _mainView.frame;
frame.origin.x += offsetX;
frame.size.height = frame.size.height *scale;
frame.size.width = frame.size.width *scale;
frame.origin.y = (screenH - frame.size.height) * 0.5; return frame;
} #define HMRTarget 250
#define HMLTarget -220
/*
_mainView.frame.origin.x > screenW * 0.5 定位到右边
CGRectGetMaxX(_mainView.frame) < screenW * 0.5 定位到左边 -220 */
// 定位
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{ // 复位
if (_isDraging == NO && _mainView.frame.origin.x != ) {
[UIView animateWithDuration:0.25 animations:^{ _mainView.frame = self.view.bounds;
}];
} CGFloat screenW = [UIScreen mainScreen].bounds.size.width; CGFloat target = ;
if (_mainView.frame.origin.x > screenW * 0.5) { // 定位到右边
target = HMRTarget;
}else if (CGRectGetMaxX(_mainView.frame) < screenW * 0.5) { // 定位到左边
target = HMLTarget;
} [UIView animateWithDuration:0.25 animations:^{ if (target) { // 在需要定位左边或者右边 // 获取x轴偏移量
CGFloat offsetX = target - _mainView.frame.origin.x; // 设置当前主视图的frame
_mainView.frame = [self getCurrentFrameWithOffsetX:offsetX]; }else{ // 还原
_mainView.frame = self.view.bounds;
}
}]; _isDraging = NO; } @end
***HMDrawViewController.h文件
#import <UIKit/UIKit.h> @interface HMDrawViewController : UIViewController @property (nonatomic, weak, readonly) UIView *mainView;
@property (nonatomic, weak, readonly) UIView *leftView;
@property (nonatomic, weak, readonly) UIView *rightView; @end