标签：key raft curl nss form eal gem cin horizon
先说初始化
- (UIPageViewController *)PageViewController{
if(!_PageViewController){
//书脊位置，只有在UIPageViewControllerTransitionStylePageCurl才生效
NSDictionary *options =[NSDictionary dictionaryWithObject:[NSNumber numberWithInteger:UIPageViewControllerSpineLocationMin]
forKey: UIPageViewControllerOptionSpineLocationKey];
//两个page之间的间距，只有UIPageViewControllerTransitionStyleScroll格式才生效
// NSDictionary *options =[NSDictionary dictionaryWithObject:[NSNumber numberWithInteger:0]
// forKey: UIPageViewControllerOptionInterPageSpacingKey];
_PageViewController = [[ UIPageViewController alloc]initWithTransitionStyle:UIPageViewControllerTransitionStylePageCurl navigationOrientation:UIPageViewControllerNavigationOrientationHorizontal options:options];
_PageViewController.view.backgroundColor = [UIColor clearColor];
_PageViewController.dataSource = self;
_PageViewController.delegate = self;
}
return _PageViewController;
}
然后填充内容
//填充PageView
- (void)setPageViewData{
[self.controllerArray removeAllObjects];
ReadingSubViewController *subView = [self viewControllerAtIndex:0];
[self.controllerArray addObject:subView];
[self.PageViewController setViewControllers:self.controllerArray direction:UIPageViewControllerNavigationDirectionForward animated:YES completion:^(BOOL finished) {
}];
}
- (ReadingSubViewController *)viewControllerAtIndex:(NSInteger)index{
NSLog(@"push%ld",index);
ReadingSubViewController *subView = [[ReadingSubViewController alloc]init];
subView.pageModel = self.bookpageData[index];
subView.bookModel = self.model;
subView.pageIndex = index;
_open = YES;
[self pushButtonClick];
return subView;
}
&&重点
重点是是他内部的运行逻辑，我也是今天才搞清楚。
先看delegate
#pragma mark ==========PageVCDelegate==========
//这个方法是返回前一个页面,如果返回为nil,那么UIPageViewController就会认为当前页面是第一个页面不可以向前滚动或翻页
- (nullable UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerBeforeViewController:(UIViewController *)viewController{
NSInteger index = [self getIndex:(ReadingSubViewController *)viewController];
NSLog(@"before=%ld",index);
if (index == 0 || index == NSNotFound) {
return nil;
}
index -- ;
ReadingSubViewController *playVC = [self viewControllerAtIndex:index];
if (index+1< 10) {
self.pageNumberLB.text = [NSString stringWithFormat:@"0%ld/%ld",index+1,_maxPage];
}else{
self.pageNumberLB.text = [NSString stringWithFormat:@"%ld/%ld",index+1,_maxPage];
}
return playVC;
}
//这个方法是下一个页面,如果返回为nil,那么UIPageViewController就会认为当前页面是最后一个页面不可以向后滚动或翻页
- (nullable UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController *)viewController{
NSInteger index = [self getIndex:(ReadingSubViewController *)viewController];
if (index == NSNotFound || index == _maxPage - 1) {
return nil;
}
NSLog(@"after=%ld",index);
index ++;
ReadingSubViewController *playVC = [self viewControllerAtIndex:index];
if (index+1< 10) {
self.pageNumberLB.text = [NSString stringWithFormat:@"0%ld/%ld",index+1,_maxPage];
}else{
self.pageNumberLB.text = [NSString stringWithFormat:@"%ld/%ld",index+1,_maxPage];
}
return playVC;
}
- (NSInteger)getIndex:(ReadingSubViewController *)subVC{
return subVC.pageIndex;
}
如果TransitionStyle是UIPageViewControllerTransitionStylePageCurl
那么从首页开始拖动的时候，往左拖动，会触发viewControllerBeforeViewController这个代理方法，并不会触发viewControllerAfterViewController代理方法。
然后每次往右拖动时只会加载一个ViewController。上面整个流程的Log如下
eadingViewController.m[88] push0 ReadingViewController.m[102] before=0 ReadingViewController.m[121] after=0 ReadingViewController.m[88] push1 ReadingViewController.m[136] 开始滚动 ReadingViewController.m[140] isCompleted:成功 ReadingViewController.m[121] after=1 ReadingViewController.m[88] push2 ReadingViewController.m[136] 开始滚动 ReadingViewController.m[140] isCompleted:成功
如果TransitionStyle是UIPageViewControllerTransitionStyleScroll
那么从首页开始拖动，不管是往右还是往左，都肯定会viewControllerAfterViewController，为PageController加载好下个Page的ViewController。我往左拖动的Log如下
ReadingViewController.m[88] push0 ReadingViewController.m[102] before=0 ReadingViewController.m[121] after=0 ReadingViewController.m[88] push1
虽然拖动完成的代理方法没有执行。但是 viewControllerAfterViewController方法触发，加载好了下一页的ViewController内容。
然后往右拖动会提前加载第三页的内容Log如下
ReadingViewController.m[102] before=0 ReadingViewController.m[121] after=0 ReadingViewController.m[88] push1 ReadingViewController.m[136] 开始滚动 ReadingViewController.m[140] isCompleted:成功 ReadingViewController.m[121] after=1 ReadingViewController.m[88] push2
如果是开始就往右拖动的话Log如下
ReadingViewController.m[88] push0 ReadingViewController.m[121] after=0 ReadingViewController.m[88] push1 ReadingViewController.m[102] before=0 ReadingViewController.m[136] 开始滚动 ReadingViewController.m[140] isCompleted:成功 ReadingViewController.m[121] after=1 ReadingViewController.m[88] push2 ReadingViewController.m[136] 开始滚动 ReadingViewController.m[140] isCompleted:成功 ReadingViewController.m[121] after=2 ReadingViewController.m[88] push3
这是拖动到第三页的时候，但是第四页其实已经预加载好了。
之前一直没有用过UIPageViewControllerTransitionStyleScroll，今天用了一次才发现自己认识的很不清晰。做下记录
标签：key raft curl nss form eal gem cin horizon
原文地址：https://www.cnblogs.com/wycstudy/p/10179036.html
