ScrollView无限滚动
typedef enum {
CycleDirectionPortait,
// 垂直滚动
CycleDirectionLandscape // 水平滚动
}CycleDirection;
@protocol CycleScrollViewDelegate;
@interface CycleScrollView : UIView <UIScrollViewDelegate> {
UIScrollView *scrollView;
UIImageView *curImageView;
int totalPage;
int curPage;
CGRect scrollFrame;
CycleDirection scrollDirection; // scrollView滚动的方向
NSArray *imagesArray; // 存放所有需要滚动的图片 UIImage
NSMutableArray *curImages; // 存放当前滚动的三张图片
id delegate;
}
@property (nonatomic, assign) id delegate;
- (int)validPageValue:(NSInteger)value;
- (id)initWithFrame:(CGRect)frame cycleDirection:(CycleDirection)direction pictures:(NSArray *)pictureArray;
- (NSArray *)getDisplayImagesWithCurpage:(int)page;
- (void)refreshScrollView;
@end
@protocol CycleScrollViewDelegate <NSObject>
@optional
- (void)cycleScrollViewDelegate:(CycleScrollView *)cycleScrollView didSelectImageView:(int)index;
- (void)cycleScrollViewDelegate:(CycleScrollView *)cycleScrollView didScrollImageView:(int)index;
@end
#import "CycleScrollView.h"
@implementation CycleScrollView
@synthesize delegate;
- (id)initWithFrame:(CGRect)frame cycleDirection:(CycleDirection)direction pictures:(NSArray *)pictureArray
{
self = [super initWithFrame:frame];
if(self)
{
scrollFrame = frame;
scrollDirection = direction;
//总共图片数量
totalPage = pictureArray.count;
// 显示的是图片数组里的第一张图片
curPage = 1;
//当前三张图片数组
curImages = [[NSMutableArray alloc] init];
//总共图片数组
imagesArray = [[NSArray alloc] initWithArray:pictureArray];
scrollView = [[UIScrollView alloc] initWithFrame:frame];
scrollView.backgroundColor = [UIColor blackColor];
scrollView.showsHorizontalScrollIndicator = NO;
scrollView.showsVerticalScrollIndicator = NO;
scrollView.pagingEnabled = YES;
scrollView.delegate = self;
[self addSubview:scrollView];
// 在水平方向滚动
if(scrollDirection == CycleDirectionLandscape) {
scrollView.contentSize = CGSizeMake(scrollView.frame.size.width * 3,
scrollView.frame.size.height);
}
// 在垂直方向滚动
if(scrollDirection == CycleDirectionPortait) {
scrollView.contentSize = CGSizeMake(scrollView.frame.size.width,
scrollView.frame.size.height * 3);
}
[self addSubview:scrollView];
[self refreshScrollView];
}
return self;
}
//--------------------------------------------------
- (void)refreshScrollView {
NSArray *subViews = [scrollView subviews];
if([subViews count] != 0) {
[subViews makeObjectsPerformSelector:@selector(removeFromSuperview)];
}
[self getDisplayImagesWithCurpage:curPage];
for (int i = 0; i < 3; i++) {
UIImageView *imageView = [[UIImageView alloc] initWithFrame:scrollFrame];
imageView.userInteractionEnabled = YES;
imageView.image = [curImages objectAtIndex:i];
UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self
action:@selector(handleTap:)];
[imageView addGestureRecognizer:singleTap];
[singleTap release];
// 水平滚动
if(scrollDirection == CycleDirectionLandscape) {
imageView.frame = CGRectOffset(imageView.frame, scrollFrame.size.width * i, 0);
}
// 垂直滚动
if(scrollDirection == CycleDirectionPortait) {
imageView.frame = CGRectOffset(imageView.frame, 0, scrollFrame.size.height * i);
}
[scrollView addSubview:imageView];
}
if (scrollDirection == CycleDirectionLandscape) {
[scrollView setContentOffset:CGPointMake(scrollFrame.size.width, 0)];
}
if (scrollDirection == CycleDirectionPortait) {
[scrollView setContentOffset:CGPointMake(0, scrollFrame.size.height)];
}
}
//--------------------------------------------------
- (NSArray *)getDisplayImagesWithCurpage:(int)page {
int pre = [self validPageValue:curPage-1];
int last = [self validPageValue:curPage+1];
if([curImages count] != 0)
[curImages removeAllObjects];
[curImages addObject:[imagesArray objectAtIndex:pre-1]];
[curImages addObject:[imagesArray objectAtIndex:curPage-1]];
[curImages addObject:[imagesArray objectAtIndex:last-1]];
return curImages;
}
//--------------------------------------------------
- (int)validPageValue:(NSInteger)value {
if(value == 0)
value = totalPage;
// value＝1为第一张，value = 0为前面一张
if(value == totalPage + 1)
value = 1;
return value;
}
- (void)scrollViewDidScroll:(UIScrollView *)aScrollView {
int
x = aScrollView.contentOffset.x;
int y = aScrollView.contentOffset.y;
NSLog(@"did x=%d y=%d", x, y);
// 水平滚动
if(scrollDirection == CycleDirectionLandscape) {
// 往下翻一张
if(x >= (2*scrollFrame.size.width)) {
curPage = [self validPageValue:curPage+1];
[self refreshScrollView];
}
if(x <= 0) {
curPage = [self validPageValue:curPage-1];
[self refreshScrollView];
}
}
// 垂直滚动
if(scrollDirection == CycleDirectionPortait) {
// 往下翻一张
if(y >= 2 * (scrollFrame.size.height)) {
curPage = [self validPageValue:curPage+1];
[self refreshScrollView];
}
if(y <= 0) {
curPage = [self validPageValue:curPage-1];
[self refreshScrollView];
}
}
if ([delegate respondsToSelector:@selector(cycleScrollViewDelegate:didScrollImageView:)]) {
[delegate cycleScrollViewDelegate:self didScrollImageView:curPage];
}
}
- (void)scrollViewDidEndDecelerating:(UIScrollView *)aScrollView {
int x = aScrollView.contentOffset.x;
int y = aScrollView.contentOffset.y;
NSLog(@"--end x=%d y=%d", x, y);
if (scrollDirection == CycleDirectionLandscape) {
[scrollView setContentOffset:CGPointMake(scrollFrame.size.width, 0) animated:YES];
}
if (scrollDirection == CycleDirectionPortait) {
[scrollView setContentOffset:CGPointMake(0, scrollFrame.size.height) animated:YES];
}
}
- (void)handleTap:(UITapGestureRecognizer *)tap {
if ([delegate respondsToSelector:@selector(cycleScrollViewDelegate:didSelectImageView:)]) {
[delegate cycleScrollViewDelegate:self didSelectImageView:curPage];
}
}
- (void)dealloc
{
[imagesArray release];
[curImages release];
[super dealloc];
}
@end