如何使用UIScrollview动态加载图像

时间:2013-10-22 11:51:11

标签: iphone ios objective-c uiview uiscrollview

我有点困惑如何使用UIScrollview或其他对象动态加载图像...

![动态显示来自webservice的图像] [1]

在上图中,它支持水平和垂直滚动图像。我们可以使用UIScrollview或其他对象(例如UICollectionView

)执行此操作

以下是用于显示7张图像的水平滚动视图的一般代码,

int x=10;
int y=20;

for (int i=1; i<=7; i++)
{
    UIView *bgView=[[UIView alloc]initWithFrame:CGRectMake(x, y, 80, 80)];
    bgView.tag=i;
    UIImageView *bgImgView=[[UIImageView alloc]initWithFrame:CGRectMake(1, 1, 55, 55)];
    bgImgView.tag=1;
    bgImgView.image=[UIImage imageNamed:[NSString stringWithFormat:@"img_%d.png",i]];
    [bgView addSubview:bgImgView];
    [self.videoscrollview addSubview:bgView];
    x=x+80;
}
self.scrollview.contentSize=CGSizeMake(7*80, 84);

我们可以使用UIView处理一个UIImageViewUIScrollview方法,使用{{1}}来显示图片吗?

我想处理不同大小的UIViews,它们是UIScrollview ...

的子视图

我用谷歌搜索但没有发现任何相关的东西。有什么建议可以解决这个问题吗?

4 个答案:

答案 0 :(得分:1)

假设你的图像名称是喜欢:images_1 / 2 ... / 10 ... / n。(确保来自此图像名称的日期图像)

试试这个:

int x=10; int y=20;

for (int i=1; i<=7; i++)
{
      UIView *bgView=[[UIView alloc]initWithFrame:CGRectMake(x, y, 80, 80)];
      bgView.tag=i;
      UIImageView *bgImgView=[[UIImageView alloc]initWithFrame:CGRectMake(1, 1, 55, 55)];
      bgImgView.tag=1;

      NSString *image = [NSString stringWithFormat:@"images_%d.png",i];
      bgImgView.image = [UIImage imageNamed:image];

     [bgView addSubview:bgImgView];
     [self.videoscrollview addSubview:bgView];
     x=x+80;
 }

 self.scrollview.contentSize=CGSizeMake(7*80, 84);

检查它是否正常工作,可能会起作用吗?

快乐的编码。

答案 1 :(得分:0)

为此,首先你必须计算并检查scrollview的可见区域,即contentOffset,然后你必须加载该可见部分的对象,当你分配新对象时,你应该将它们存储在一个数组中。当任何图像移动到可见区域之外时,您应该将其从滚动视图中移除。 这样它将占用更少的内存,您可以加载许多图像而不会收到内存警告。

您可以按照本文获取一些提示,以便如何在scrollView

中添加和删除对象

http://www.raywenderlich.com/10518/how-to-use-uiscrollview-to-scroll-and-zoom-content

答案 2 :(得分:0)

Try this for dynamic image From NSBundle:

NSString * resourcePath = [[NSBundle mainBundle] resourcePath];
NSError * error;
NSArray * directoryContents = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:resourcePath error:&error];
NSMutableArray *imageArray = [[NSMutableArray alloc]init];

for (int i=0; i<directoryContents.count; i++) {
    NSString *pathExtension = [[directoryContents objectAtIndex:i] pathExtension];
    if ([pathExtension isEqualToString:@"png"]  || [pathExtension isEqualToString:@"jpg"] ) {
        [imageArray addObject:[directoryContents objectAtIndex:i]];
    }
}
Now u have array of all images

for (int i=1; i<=imageArray.count; i++)
{
  UIView *bgView=[[UIView alloc]initWithFrame:CGRectMake(x, y, 80, 80)];
  bgView.tag=i;
  UIImageView *bgImgView=[[UIImageView alloc]initWithFrame:CGRectMake(1, 1, 55, 55)];
  bgImgView.tag=1;
  bgImgView.image=[UIImage imageNamed:[imageArray objectAtIndex:i]];
  [bgView addSubview:bgImgView];
 [self.videoscrollview addSubview:bgView];
  x=x+80;

} self.scrollview.contentSize = CGSizeMake(i * 80,84);

答案 3 :(得分:0)

感谢您的宝贵答案。我使用下面的代码暂时解决了上述问题。

Bool isOddViewNo; //在.h文件

isOddViewNo = YES; //在viewDidLoad

int x=10;
int y=10;

for (int i=0; i<=15; i++)
{
    if (isOddViewNo)
    {
        isOddViewNo=NO;
        UIView *oddView=[[UIView alloc]initWithFrame:CGRectMake(x, y, 90, 90)];
        UIImageView *oddImgView=[[UIImageView alloc]initWithFrame:CGRectMake(1, 1, 85, 85)];
        oddImgView.image=[UIImage imageNamed:[NSString stringWithFormat:@"img_%d.png",i]];
        [oddView addSubview:oddImgView];
        [self.scrollview addSubview:oddView];
        x+=90;
    }
    else
    {
        isOddViewNo=YES;
        UIView *evenView=[[UIView alloc]initWithFrame:CGRectMake(x, y, 150, 150)];
        UIImageView *evenImgView=[[UIImageView alloc]initWithFrame:CGRectMake(1, 1, 145, 145)];
        evenImgView.image=[UIImage imageNamed:[NSString stringWithFormat:@"img_%d.png",i]];
        [evenView addSubview:evenImgView];
        [self.scrollview addSubview:evenView];
        x+=150;
    }

    if ((i+1)%3==0)
    {
        //if added image is 4 th image
        y+=150;
        x=10;
    }

    if (y+150>self.scrollview.frame.size.height)
    {
        self.scrollview.contentSize=CGSizeMake(400, y+150);
    }
    else
    {
        self.scrollview.contentSize=CGSizeMake(320, self.scrollview.frame.size.height+150);
    }
}

![我在UIScrollview的每一行显示三个不同大小的视图。哪个可以水平和垂直滚动。这是从模拟器拍摄的屏幕截图] [1]