UIScrollView代码实现循环滚动

iPhone开发应用中循环滚动一个UIScrollView代码实现是本文要介绍的内容，主要是介绍UIScrollView来实现循环滚动的案例，来看详细内容。

// testScrollViewViewController.m

// testScrollView

// Created by cash on 11-7-4.

// Copyright 2011年 xbiii3s@gmail.com. All rights reserved.

#import "testScrollViewViewController.h"

@implementation testScrollViewViewController

@synthesize scrollView, slideImages;

#define WIDTH_OF_SCROLL_PAGE 320

#define HEIGHT_OF_SCROLL_PAGE 460

#define WIDTH_OF_IMAGE 320 #define HEIGHT_OF_IMAGE 460

#define LEFT_EDGE_OFSET 0

- (void)viewDidLoad {

scrollView = [[UIScrollView alloc] init];

CGRect scrollFrame;

scrollFrame.origin.x = 0;

scrollFrame.origin.y = 0;

scrollFrame.size.width = WIDTH_OF_SCROLL_PAGE;

scrollFrame.size.height = HEIGHT_OF_SCROLL_PAGE;

scrollView = [[UIScrollView alloc] initWithFrame:scrollFrame];

scrollView.bounces = YES;

scrollView.pagingEnabled = YES;

scrollView.delegate = self;

scrollView.userInteractionEnabled = YES;

slideImages = [[NSMutableArray alloc] init];

[slideImages addObject:@"IMG_0116.PNG"];

[slideImages addObject:@"IMG_0118.PNG"];

[slideImages addObject:@"IMG_0119.PNG"];

[slideImages addObject:@"main_bg.png"];

//add the last image first

UIImageView *imageView = [[UIImageView alloc]

initWithImage:[UIImage imageNamed:[slideImages objectAtIndex:([slideImages count]-1)]]]

imageView.frame = CGRectMake(LEFT_EDGE_OFSET, 0, WIDTH_OF_IMAGE, HEIGHT_OF_IMAGE);

[scrollView addSubview:imageView];

[imageView release];

for (int i = 0;i<[slideImages count];i++) {

//loop this bit

UIImageView *imageView = [[UIImageView alloc]

initWithImage:[UIImage imageNamed:[slideImages objectAtIndex:i]]];

imageView.frame = CGRectMake((WIDTH_OF_IMAGE * i) + LEFT_EDGE_OFSET + 320, 0, WIDTH_OF_IMAGE, HEIGHT_OF_IMAGE);

[scrollView addSubview:imageView];

[imageView release];

}

//add the first image at the end

imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:[slideImages objectAtIndex:0]]];

imageView.frame = CGRectMake((WIDTH_OF_IMAGE * ([slideImages count] + 1)) + LEFT_EDGE_OFSET, 0, WIDTH_OF_IMAGE, HEIGHT_OF_IMAGE);

[scrollView addSubview:imageView];

[imageView release];

[scrollView setContentSize:CGSizeMake(WIDTH_OF_SCROLL_PAGE * ([slideImages count] + 2), HEIGHT_OF_IMAGE)];

[scrollView setContentOffset:CGPointMake(0, 0)];

[self.view addSubview:scrollView];

[self.scrollView scrollRectToVisible:CGRectMake(WIDTH_OF_IMAGE,0,WIDTH_OF_IMAGE,HEIGHT_OF_IMAGE) animated:NO];

[super viewDidLoad];} - (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {

int currentPage = floor((self.scrollView.contentOffset.x - self.scrollView.frame.size.width

/ ([slideImages count]+2)) / self.scrollView.frame.size.width) + 1;

if (currentPage==0) {

//go last but 1 page

[self.scrollView scrollRectToVisible:CGRectMake(WIDTH_OF_IMAGE * [slideImages count],0,WIDTH_OF_IMAGE,HEIGHT_OF_IMAGE) animated:NO];

} else

if (currentPage==([slideImages count]+1)) {

//如果是最后+1,也就是要开始循环的第一个

[self.scrollView scrollRectToVisible:CGRectMake(WIDTH_OF_IMAGE,0,WIDTH_OF_IMAGE,HEIGHT_OF_IMAGE) animated:NO];

}

}

- (void)didReceiveMemoryWarning {

// Releases the view if it doesn't have a superview.

[super didReceiveMemoryWarning];

// Release any cached data, images, etc that aren't in use.

}

- (void)viewDidUnload {

// Release any retained subviews of the main view.

// e.g. self.myOutlet = nil;

}

- (void)dealloc {

[scrollView release];

[slideImages release];

[super dealloc];

}

@end