如何在我的應用程序中使用UIPageControl？

Question

我正在製作一個應用程序，我需要使用UIPageControl滾動瀏覽一些圖像。可悲的是，我不知道如何使用UIPageControl或UIScrollView。通過Apple的YouTube視頻或Xcode文檔鏈接將非常感謝！

在此先感謝！

Answer 1

這裏是一個代碼，這將有助於你

CGSize size = [[UIScreen mainScreen] bounds].size; 
CGFloat frameX = size.width; 
CGFloat frameY = size.height-30; //padding for UIpageControl 

UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(offsetX, offsetY, frameX, frameY)]; 
scrollView.pagingEnabled = YES; 

scrollView.backgroundColor = [UIColor clearColor]; 
scrollView.contentSize = CGSizeMake(frameX, frameY); 


[self.view addSubview: scrollView]; 

//我們說你有圖像的陣列中imageArray

for(int i = 0; i < [imageArray]; i++) 
{ 
    UIImage *image = [UIImage imageNamed:[imageArray objectAtIndex:i]]; 
    imageView = [[UIImageView alloc] initWithImage:image]; 
    imageView.frame = CGRectMake(frameX * i, 0.0, frameX, frameY); 
    [scrollView addSubview:imageView]; 
} 

scrollView.contentSize = CGSizeMake(frameX*[imageArray count], frameY); 

請根據使用範圍申報的變量。我已經宣佈當地所有的變量，這樣就可能無法獲得混淆視聽，還添加UIPageControl在你的ViewController

的底部實施的UIScrollView的委託方法在當前頁面指示符

- (void)scrollViewDidScroll:(UIScrollView *)scrollView 
    { 
    width = scrollView.frame.size.width; 
    float xPos = scrollView.contentOffset.x+10; 

    //Calculate the page we are on based on x coordinate position and width of scroll view 
    pageControl.currentPage = (int)xPos/width; 
    } 

其中的PageControl是UIPageControl加在底部你的ViewController

Answer 2

這是一個非常好的教程由雷Wenderlich團隊如何建立尋呼滾動視圖：How To Use UIScrollView to Scroll and Zoom Content

蘋果DOCUME ntation還有一個如何實現分頁滾動視圖的示例：PhotoScroller

My answer到this previous question也可能對您有用。

Answer 3

滾動型：

滾動型被用於顯示多數意見/對象。我們可以通過水平或垂直滾動​​顯示這些視圖。 您可以處理縮放，平移，滾動等

你可以通過一些教程 Are there any good UIScrollView Tutorials on the net?

https://developer.apple.com/library/ios/documentation/windowsviews/conceptual/UIScrollView_pg/CreatingBasicScrollViews/CreatingBasicScrollViews.html

示例代碼了滾動：

UIScrollView *scroll = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0,self.view.frame.size.width, self.view.frame.size.height)]; 
//This will create a scrollview of device screen frame 

您可以啓用滾動

scroll.scrollEnabled = YES; 

實施例，用於將3次到滾動型

NSInteger numberOfViews = 3; 
for (int i = 0; i < numberOfViews; i++) { 
     CGFloat xOrigin = i * self.view.frame.size.width; 
     UIView *awesomeView = [[UIView alloc] initWithFrame:CGRectMake(xOrigin, 0, self.view.frame.size.width, self.view.frame.size.height)]; 
     awesomeView.backgroundColor = [UIColor colorWithRed:0.5/i green:0.5 blue:0.5 alpha:1]; 
     [scroll addSubview:awesomeView]; 
     [awesomeView release]; 
} 
// 3 views added horizontally to the scrollview by using xOrigin. 

最重要的部分在此爲是瞭解xOrigin。這將把每個UIView放在前一個UIView停止的位置，換句話說，每個UIView將在前一個UIView的末尾開始。 現在我們獲得了3個視圖的滾動視圖，並且可以水平添加。

設置的UIScrollView contentSize

scroll.contentSize = CGSizeMake(self.view.frame.size.width * numberOfViews, self.view.frame.size.height); 

的contentSize是三個UIViews的寬度的簡單相加，如果每個UIView的寬度爲320，和我們有三個UIViews，您的contentSize寬度爲920 。

[self.view addSubview:scroll]; 
[scroll release]; 
//Add scrollview to viewcontroller 

頁面控制： A頁數控制呈現一組表示頁水平點的用戶。當前頁面呈現爲白點。用戶可以從當前頁面轉到下一頁面或前一頁面。

要啓用分頁，您需要添加

scroll.pagingEnabled = YES; 
pageControl = [[UIPageControl alloc] init]; //SET a property of UIPageControl 
pageControl.frame = CGRectMake(100,self.view.frame.size.height-100,self.view.frame.size.width-200,100); 
pageControl.numberOfPages = 3; //as we added 3 diff views 
pageControl.currentPage = 0; 

添加委託方法滾動型的實施的PageControl點滾動時

- (void)scrollViewDidScroll:(UIScrollView *)scrollView { 
      CGFloat pageWidth = self.scrollView.frame.size.width; 
      int page = floor((self.scrollView.contentOffset.x – pageWidth/2)/pageWidth) + 1; //this provide you the page number 
      pageControl.currentPage = page;// this displays the white dot as current page 
    } 

現在你可以看到的PageControl了滾動。希望你能理解。請參閱本太 https://developer.apple.com/library/ios/documentation/uikit/reference/UIPageControl_Class/Reference/Reference.html