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how to implement photo slide show in iphone?

开发者 https://www.devze.com 2023-02-28 06:18 出处:网络
Hello i have implemented photo slideshow with scrollview and imageview using apple\'s scrolling example

Hello i have implemented photo slideshow with scrollview and imageview using apple's scrolling example

- (void)viewDidLoad {

    kNumImages=[parray count];
    self.view.backgroundColor=[UIColor viewFlipsideBackgroundColor];
    [scrollView1 setBackgroundColor:[UIColor blackColor]];
    [scrollView1 setCanCancelContentTouches:NO];
    scrollView1.indicatorStyle=UIScrollViewIndicatorStyleWhite;
    scrollView1.clipsToBounds=YES;
    scrollView1.scrollEnabled=YES;   
    scrollView1.pagingEnabled=YES;
    scrollView1.minimumZoomScale=0.5;
    scrollView1.delegate=self;
    scrollView1.maximumZoomScale=6.0;
    NSUInteger i;
    for(i=0;i<kNumImages;i++)
    {

        NSURL *url=[NSURL URLWithString:[parray objectAtIndex:i]];
        NSLog(@"url object at index %i is %@",i,url);
        //NSString *imageName=[NSString stringWithFormat:@"image%d.jpg",i ];
        UIImage *image=[UIImage imageWithData:[NSData dataWithContentsOfURL:url]];
        imageView=[[UIImageView alloc] initWithImage:image];
        CGRect rect=imageView.frame;
        rect.size.height=kScrollObjHeight;
        rect.size.width=kScrollObjWidth;
        imageView.frame=rect;
        imageView.tag=i+1;
        [scrollView1 addSubview:imageView];
        [imageView release];
    }

    [self layoutScrollImages];
    [super viewDidLoad];
}

-(void)layoutScrollImages
{
    kNumImages=[parray count];
    view=nil;
    NSArray *subviews=[scrollView1 subviews];
    CGFloat curXLoc=0;
    for(view i开发者_如何转开发n subviews)
    {
        if([view isKindOfClass:[UIImageView class]] && view.tag>0)
        {
            CGRect frame=view.frame;
            frame.origin=CGPointMake(curXLoc, 0);
            view.frame=frame;
            curXLoc+=(kScrollObjWidth);
        }}
    [scrollView1 setContentSize:CGSizeMake((kNumImages *kScrollObjWidth),[scrollView1 bounds].size.height)];

}

this works fine.but the image sequence here starts from first image from image array instead of that i want any image say image number 3 wants to appears first in view when page is loaded and when i scroll left it should show image no.2 and when i scroll right it should show image 4.How can i do that? UPDATE: i have solved the issue using following code:

CGPoint lastFrame = CGPointMake(( 2* kScrollObjWidth), 0.0f);
[scrollView1 setContentOffset:lastFrame];


I have solved the issue using following code:

CGPoint lastFrame = CGPointMake(( 2* kScrollObjWidth), 0.0f); [scrollView1 setContentOffset:lastFrame];


You should have a look at the PageControl which shows how paging works with a UIScrollView and connect it to UIPageControl. You could easily adapt that code and put in your array of images in the order you need. It's memory efficient: only three UIImageViews are used at the same time.

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