[英]iPhone App how to programmatically detect Scrolling of scrollview?
[英]How to load bundle of images in a scrollview with horrizondal scrolling in iphone?
我有一个iPhone应用程序,需要加载大量图像(即50张左右),该图像有一个小矩形(略高于缩略图),每行包含3个,一页中有4列,并且我需要水平滚动加载接下来的12张图像,依此类推。 我还需要显示它下的页码为1,2等。
任何人都可以在正确的方向上引导我在滚动视图中实现这一目标吗?我真的一团糟,如何向这样的滚动视图添加imageview,每个图像视图也都有自己的按钮。
我解决此问题的方法如下:(由于它们取决于您的特定需求和要求,因此我将不提供许多详细信息)。
.h文件:
#import <UIKit/UIKit.h>
@interface ViewController : UIViewController <UIScrollViewDelegate>
@property (unsafe_unretained, nonatomic) IBOutlet UIScrollView *scrollView;//assuming the scrollView is connected in a xib file
-(id)initWithImages:(NSArray*)images;//that could be whatever format you get your images(UIImage, urls to download, file names or custom views. Here we assume that the array contains instances of UIImage)
@end
.m文件:
#import "ViewController.h"
@interface ViewController ()
@property (nonatomic, strong) NSArray *images;
@property (nonatomic, assign) CGFloat pageWidth;
@property (nonatomic, assign) int currentPage;
@end
@implementation ViewController
-(id)initWithImages:(NSArray*)images{
self = [super init];
if(self){
self.images = images;
}
return self;
}
-(void)viewDidLoad{
[super viewDidLoad];
[self.scrollView setDelegate:self];
[self.scrollView setContentSize:CGSizeMake(self.scrollView.frame.size.width*self.imageURLsArray.count,
self.scrollView.frame.size.height)];
[self.scrollView setPagingEnabled:YES];
[self.scrollView setShowsVerticalScrollIndicator:NO];
self.pageWidth = self.scrollView.frame.size.width;
for(int i = 0; i < self.images.count; i++){
UIImageView *imageView = [[UIImageView alloc]initWithFrame:CGRectMake(self.scrollView.frame.size.width*i,
self.scrollView.frame.origin.y,
self.scrollView.frame.size.width,
self.scrollView.frame.size.height)];
imageView.image = [self.images objectAtIndex:i];
[self.scrollView addSubview:imageView];
}
}
-(void)scrollViewDidScroll:(UIScrollView *)scrollView{
int page = floor(scrollView.contentOffset.x - self.pageWidth/2)/self.pageWidth + 1;
if(self.currentPage != page){
NSLog(@"Scrolled to new page: %d", page);
self.currentPage = page;
//do additional things based on the fact that you have scrolled to a new page (like changing the page number)
}
}
@end
使用UItableview创建带有两个图像视图的自定义单元格,并将该自定义单元格加载到索引路径的单元格中,然后创建一个nsarray并将图像名称传递到该数组中,然后将该图像转换为数据格式,例如
nsdata * data = [URL的NSdata dataWithcontents [索引为indexpath.row的数组对象]]; cell.imageview.image = [uiimage imagewithdata:data]; 为此,您应该知道创建自定义单元。
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.