ios - ios中图片的 ScrollView

Question

您好，我的要求是在 scrollview 中显示图像，同时它应该显示 next 和 previous 按钮。用户也可以滚动图像就像使用按钮移动图像一样。

我对如何获取 index/tag/imagename 或用户基于该值按钮滚动时的任何其他内容有疑问已更新。

这是我的代码

[self arrayInitiaisation];  
scrollview.pagingEnabled = YES;
scrollview.alwaysBounceVertical = NO;
scrollview.alwaysBounceHorizontal = YES;
NSInteger numberOfViews = 4;

for (int i = 0; i < numberOfViews; i++) {

    CGFloat xOrigin = i*320;
    imageView.image = [UIImage imageNamed:[NSString stringWithFormat:@"image%d",i+1]];
    imageView.contentMode = UIViewContentModeScaleAspectFit;
    [self.scrollview addSubview:imageView];
    imageView.tag = i;
    ...  

数组初始化方法

-(void) arrayInitialisation {

  count=0;
  [super viewDidLoad];
  images=[NSMutableArray arrayWithObjects : [UIImage imageNamed:@"image1.png"],
    [UIImage imageNamed :@"image2.png"],
    [UIImage imageNamed :@"image3.png"],
    [UIImage imageNamed :@"image4.png"],nil];
    [imageView setImage:[images objectAtIndex:0]];
    NSLog(@"Array Length :%d",images.count);
    [previous setEnabled:NO];
} 

行动方法

- (IBAction)nextButton:(id)sender {}
- (IBAction)prevButton:(id)sender {}

滚动工作正常，但当用户点击 prev 和 next 时，图像不会在“imageview”上更新

这是我更新后的代码

    int count=0;

    - (void)viewDidLoad
    {
    [super viewDidLoad];
    [self arrayInitialisation];
    [scrollview setScrollEnabled:YES];
    self.scrollview =[[UIScrollView alloc] initWithFrame:CGRectMake(30 , 30, 320, 412)];
    self.scrollview.delegate=self;
    scrollview.pagingEnabled = YES;
    scrollview.alwaysBounceVertical=NO;
    scrollview.alwaysBounceHorizontal=YES;
    scrollview.showsHorizontalScrollIndicator=NO;
    NSInteger numberOfViews = 4;
    for (int i = 0; i < numberOfViews; i++) {
    CGFloat xOrigin = i*320;
    imageView = [[UIImageView alloc]initWithFrame:CGRectMake(xOrigin, 0, 320, 412)];
    imageView.image = [images objectAtIndex:i];
    imageView.contentMode = UIViewContentModeScaleAspectFit;
    [self.scrollview addSubview:imageView];
    imageView.tag=i;


}

scrollview.contentSize = CGSizeMake(320*numberOfViews, 412);
scrollview.contentOffset = CGPointMake(0,0);
[self.view addSubview:self.scrollview];
}

    - (void)didReceiveMemoryWarning
      {
         [super didReceiveMemoryWarning];
         }
      -(void) arrayInitialisation{
       count=0;
        [super viewDidLoad];
       images=[NSArray arrayWithObjects :  [UIImage imageNamed:@"image1.png"],
        [UIImage imageNamed :@"image2.png"],
        [UIImage imageNamed :@"image3.png"],
        [UIImage imageNamed :@"image4.png"],nil];
     [imageView setImage:[images objectAtIndex:0]];
     NSLog(@"Array Length :%d",images.count);
    [previous setEnabled:NO];
    }


   - (IBAction)nextButton:(id)sender {
    if(count==0){
    count++;
    NSLog(@"Next Button : if Loop %d",count);
    [imageView setImage:[images objectAtIndex:count]];
    [previous setEnabled:YES];

      }
       else{

    [previous setEnabled:YES];
    count++;
     NSLog(@"Next Button : else Loop %d",count);
    if(count <images.count){
        [imageView setImage:[images objectAtIndex:count]];
    }
    else{
        [next setEnabled:NO];

    }
    }

     }

      - (IBAction)prevButton:(id)sender {
       if(count==0){
      //count--;
       NSLog(@"prev Button : if Loop %d",count);
     [imageView setImage:[images objectAtIndex:count]];
     [previous setEnabled:NO];
    [next setEnabled:YES];
    }
    else{
    count--;
     NSLog(@"prev Button : else Loop %d",count);
    [imageView setImage:[images objectAtIndex:count]];
    [previous setEnabled:YES];
    //[next setEnabled:YES];
   }
  }
    #pragma mark - ScrollView Delegate

    - (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:    (BOOL)decelerate{
    //NSLog(@"scrollViewDidEndDragging");
    /* count=count+1;
    NSLog(@"scrollViewDidEndDragging : %d",count);*/
   }
    - (void)scrollViewDidScroll:(UIScrollView *)scrollView{
    //NSLog(@"scrollViewDidScroll");

    }
     - (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset NS_AVAILABLE_IOS(5_0){
    //NSLog(@"scrollViewWillEndDragging");
    count=count+1;
    NSLog(@"scrollViewWillEndDragging : %d",count);

       }  

Answer 1

我有用于滚动图像的左右按钮，并且 imageview 宽度相同。

我正在编写按下按钮时滚动图像的代码。

int pos=0;//ViewDiaLoad

- (IBAction)OnClickLeftButton:(UIButton*)sender
{
    if(pos>0)
    {
        pos -=1;
        [scrlDemandMenu scrollRectToVisible:CGRectMake(pos*scrlDemandMenu.frame.size.width, 0, scrlDemandMenu.frame.size.width, scrlDemandMenu.frame.size.height) animated:YES];

    }
}

- (IBAction)OnClickRightButton:(UIButton*)sender
{
    if(pos<numberOfImages)
    {
        pos +=1;
        [scrlDemandMenu scrollRectToVisible:CGRectMake(pos*scrlDemandMenu.frame.size.width, 0, scrlDemandMenu.frame.size.width, scrlDemandMenu.frame.size.height) animated:YES];
    }
} 

设置 ScrollView 委托(delegate)

ScrollView 委托(delegate)方法

-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
   pos=scrollView.contentOffset.x/scrollView.frame.size.width;
}