我有一个使用导航控制器的设置,该控制器包括一个嵌入页面视图控制器及其内容的容器视图。
从左:UINavigationController,我的类MTNewsViewController继承自UIViewController并实现UIPageViewControllerDataSource(持有容器视图),UIPageViewController,我的类MTNewsContentController继承自UIViewController。
我设法通过自定义文本和图像将许多页面插入到页面控制器中。但是,问题是容器视图的位置和大小。它的位置不是图像故事板所建议的,而是从左上角以另一种尺寸放置。像这样:
我不确定缺少什么。
以下是一些代码段。您对可能出什么问题有任何建议吗?我怀疑我需要在某个地方设置大小。
MTNewViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Create page view controller
self.pageViewController.dataSource = self;
[self loadNews];
MTNewsContentController *startingViewController = [self viewControllerAtIndex:0];
NSArray *viewControllers = @[startingViewController];
[self.pageViewController setViewControllers:viewControllers direction:UIPageViewControllerNavigationDirectionForward animated:NO completion:nil];
[self addChildViewController:_pageViewController];
[self.view addSubview:_pageViewController.view];
[self.pageViewController didMoveToParentViewController:self];
UIPageControl* pageControlDots = [UIPageControl appearanceWhenContainedInInstancesOfClasses:@[[MTNewsViewController class]]];
pageControlDots.pageIndicatorTintColor = [UIColor lightGrayColor];
pageControlDots.currentPageIndicatorTintColor = [UIColor blackColor];
pageControlDots.hidesForSinglePage = YES;
}
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
self.pageViewController = segue.destinationViewController;
self.pageViewController.view.frame = segue.destinationViewController.view.frame;
}
- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerBeforeViewController:(UIViewController *)viewController
{
NSUInteger index = [self getCurrentPageIndex:viewController];
if ((index == 0) || (index == NSNotFound)) {
return nil;
}
return [self viewControllerAtIndex:--index];
}
- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController *)viewController
{
NSUInteger index = [self getCurrentPageIndex:viewController];
if (index == NSNotFound) {
return nil;
}
if (++index == news.size()) {
return nil;
}
return [self viewControllerAtIndex:index];
}
- (MTNewsContentController *)viewControllerAtIndex:(NSUInteger)index
{
if ((news.size() == 0) || (index >= news.size())) {
return nil;
}
// Create a new view controller and pass suitable data.
MTNewsContentController *newPage = [self.storyboard instantiateViewControllerWithIdentifier:@"NewsPageContentController"];
newPage.imagePath = [NSString stringWithCString:news[index].kImagePath.c_str() encoding:NSUTF8StringEncoding];
newPage.textDescription = [NSString stringWithCString:news[index].kDescription.c_str() encoding:NSUTF8StringEncoding];
newPage.pageIndex = index;
return newPage;
}
- (NSInteger)presentationCountForPageViewController:(UIPageViewController *)pageViewController
{
return news.size();
}
- (NSInteger)presentationIndexForPageViewController:(UIPageViewController *)pageViewController
{
return 0;
}
- (NSUInteger)getCurrentPageIndex:(UIViewController *)viewController {
return ((MTNewsContentController*) viewController).pageIndex;
}
MTNewsContentController这里没什么特别的。只需以编程方式添加图像和一些文本。
我认为您很可能没有在容器视图上放置布局约束。结果,它在运行时的显示方式可能与情节提要中的显示方式不同。该容器视图必须在水平和垂直方向上都受到约束。您可以选择容器视图,然后在按住Ctrl键的同时将其拖动到其父视图。然后将弹出一个约束菜单。按住Shift键,然后选择最上面的四个选项,即到安全区域的前导和尾随空格,到安全区域的顶部和底部空格。确保在每个框旁边打勾。然后尝试再次运行您的应用。