利用手勢操作實現抽屜效果：
第一步：搭建UI
(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;
}
第二步：獲取手勢操作對象，獲取手勢移動大小
- (void)touchesMoved:(NSSet )touches withEvent:(UIEvent )event
{
// 獲取UITouch對象
UITouch *touch = [touches anyObject];
// 獲取當前點
CGPoint currentPoint = [touch locationInView:self.view];// 獲取上一個點
CGPoint prePoint = [touch previousLocationInView:self.view];// x軸偏移量：當手指移動一點的時候，x偏移多少
CGFloat offsetX = currentPoint.x - prePoint.x;// 設置當前主視圖的frame
_mainView.frame = [self getCurrentFrameWithOffsetX:offsetX];_isDraging = YES;
}
第三步：利用手勢平移量來重寫計算新的frame
//#define HMMaxY 60
// 當手指偏移一點，根據X軸的偏移量算出當前主視圖的frame
- (CGRect)getCurrentFrameWithOffsetX:(CGFloat)offsetX
{
CGFloat screenW = [UIScreen mainScreen].bounds.size.width;
CGFloat screenH = [UIScreen mainScreen].bounds.size.height;
// 獲取y軸偏移量，手指每移動一點，y軸偏移多少
CGFloat offsetY = offsetX * HMMaxY / screenW;CGFloat scale = (screenH - 2 * offsetY) / screenH;if (_mainView.frame.origin.x < 0) { // 往左邊滑動scale = (screenH + 2 * offsetY) / screenH;
}// 獲取之前的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;
}
第四步：定位于復位業務邏輯
//#define HMRTarget 250
//#define HMLTarget -220
/*
_mainView.frame.origin.x > screenW * 0.5 定位到右邊
CGRectGetMaxX(_mainView.frame) < screenW * 0.5 定位到左邊 -220
*/
// 定位
- (void)touchesEnded:(NSSet )touches withEvent:(UIEvent )event
{
// 復位
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) { // 定位到右邊target = HMRTarget;
}else if (CGRectGetMaxX(_mainView.frame) < screenW * 0.5) { // 定位到左邊target = HMLTarget;
}[UIView animateWithDuration:0.25 animations:^{if (target) { // 在需要定位左邊或者右邊// 獲取x軸偏移量CGFloat offsetX = target - _mainView.frame.origin.x;// 設置當前主視圖的frame_mainView.frame = [self getCurrentFrameWithOffsetX:offsetX];}else{ // 還原_mainView.frame = self.view.bounds;}
}];_isDraging = NO;
}
)
)
)
