本文实例为大家分享了iOS实现简单抽屉效果的具体代码，供大家参考，具体内容如下
实现思路及步骤：
1、首先准备要滑动的view
#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;
}
2、监听触摸事件，记录横轴方向的偏移量，有了偏移量就可以通过偏移量改动视图的位置
#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;
}
如何实时监听一个对象的属性(只能监听对象，不能监听结构体)?kvo
// 1.监听 2 ，实现：observeValueForKeyPath 方法
/**
* 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]; //实时监听mainview的frame
// 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));//当前的frame
if (_mainView.frame.origin.x < 0) { // 主界面的x<0,往左移动
// 显示右边
_rightView.hidden = NO;
// 隐藏左边
_leftView.hidden = YES;
}else if (_mainView.frame.origin.x > 0){ // 往右移动
// 显示左边
_rightView.hidden = YES;
// 隐藏右边
_leftView.hidden = NO;
}
}
当x轴偏移的时候，如何缩放高度？
当x偏移时，y轴缩小为: x的偏移量/
#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;//HMMaxY 缩放的最大Y
CGFloat scale = (screenH - 2 * offsetY) / screenH;//比例
if (_mainView.frame.origin.x < 0) { // 往左边滑动
scale = (screenH + 2 * 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;
}
定位：
#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 != 0) {
[UIView animateWithDuration:0.25 animations:^{
_mainView.frame = self.view.bounds;
}];
}
CGFloat screenW = [UIScreen mainScreen].bounds.size.width;
CGFloat target = 0;
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;
}
全：
@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 < 0) { // 往左移动
// 显示右边
_rightView.hidden = NO;
// 隐藏左边
_leftView.hidden = YES;
}else if (_mainView.frame.origin.x > 0){ // 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 - 2 * offsetY) / screenH;
if (_mainView.frame.origin.x < 0) { // 往左边滑动
scale = (screenH + 2 * 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 != 0) {
[UIView animateWithDuration:0.25 animations:^{
_mainView.frame = self.view.bounds;
}];
}
CGFloat screenW = [UIScreen mainScreen].bounds.size.width;
CGFloat target = 0;
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;
}
