xamarin.ios 使用仅图像代码实现 PageController

Posted 2023-03-16

【中文标题】xamarin.ios 使用仅图像代码实现 PageController

【英文标题】：xamarin.ios implement PageController with images only code

【发布时间】：2016-08-06 15:01:26

【问题描述】：

我正在开发一个带有 xamarin、只有代码、没有 StoryBoard 或任何设计器的 ios 应用程序。 我需要实现一个包含许多图像并水平滚动的 UiViewController，就像this。

我没有找到适合我的东西。 所以有人有一些建议或一些例子给我看吗？

【问题讨论】：

该链接适用于 tvOS，而不是 iOS

【参考方案1】：

您似乎需要一个没有情节提要或 .xib 的 UIPageViewController。

你需要 3 个自定义类来实现它。

MyPageViewController - 自定义UIPageViewController

public class MyPageViewController : UIPageViewController

    private List<ContentViewController> pages = new List<ContentViewController>();

    public MyPageViewController() : base(UIPageViewControllerTransitionStyle.Scroll, UIPageViewControllerNavigationOrientation.Horizontal)
    
        View.Frame = UIScreen.MainScreen.Bounds;

        pages.Add(new ContentViewController(0,UIColor.Red));
        pages.Add(new ContentViewController(1,UIColor.Green));
        pages.Add(new ContentViewController(2,UIColor.Blue));

        DataSource = new PageDataSource(pages);

        SetViewControllers(new UIViewController[]  pages [0] as UIViewController , UIPageViewControllerNavigationDirection.Forward, false, null);
    

PageDataSource:

public class PageDataSource : UIPageViewControllerDataSource

    List<ContentViewController> pages; 

    public PageDataSource(List<ContentViewController> pages)
    
        this.pages = pages;
    

    override public UIViewController GetPreviousViewController(UIPageViewController pageViewController, UIViewController referenceViewController)
    
        ContentViewController currentPage = referenceViewController as ContentViewController;
        ContentViewController pageToReturn = null;

        if (currentPage.Index == 0)
        
            pageToReturn = pages[pages.Count - 1];
        
        else
        
            pageToReturn = pages[currentPage.Index - 1];
        

        // NOTE: If the same view controller is returned, UIPageViewController will break and show black screen
        return pageToReturn != currentPage ? pageToReturn : null; 
    

    override public UIViewController GetNextViewController(UIPageViewController pageViewController, UIViewController referenceViewController)
    
        ContentViewController currentPage = referenceViewController as ContentViewController;
        ContentViewController pageToReturn = pages[(currentPage.Index + 1) % pages.Count];

        return pageToReturn != currentPage ? pageToReturn : null;
    

ContentViewController - 自定义UIViewController，只需添加属性Index

public class ContentViewController : UIViewController

    private int index = -1;
    public int Index
    
        get
         
            return index;
        
    

    public ContentViewController(int _index, UIColor backColor)
    
        this.index = _index;
        this.View.Frame = UIScreen.MainScreen.Bounds;
        this.View.BackgroundColor = backColor;
    

最后，覆盖 AppDelegate.cs 中的 FinishedLaunching 方法：

public override bool FinishedLaunching(UIApplication application, NSDictionary launchOptions)

    this.Window = new UIWindow(UIScreen.MainScreen.Bounds);
    this.Window.RootViewController = new MyPageViewController();
    this.Window.MakeKeyAndVisible();

    return true;

希望对你有帮助。

如果您还有问题，请在此处留下。