How to Dynamically Load Images Using UIScrollview - iphone

Question

I am bit confused how to accomplish to load images dynamically using UIScrollview or other objects ...
![Dynamically displaying images coming from webservice][1]
In the above image it supports both horizontal and vertical scrolling of images. Can we do this using UIScrollview or other objects like UICollectionView?
Below is the general code for horizontal scrollview for displaying 7 images,
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);
Can we handle with one UIView and UIImageView like above method using UIScrollview for displaying images?
I want to handle UIViews with different sizes which are subviews to UIScrollview...
I googled but not found any related stuff. Any suggestions to deal with this?

Answer 1

Assuming that your image names are Likes: images_1/2.../10.../n.(Make sure daynamic image coming from this imagename)
Try this one :
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);
check that it's working or not,may be it will work?
happy coding.

Answer 2

For this, first you have to calculate and check for the visible area of scrollview i.e. contentOffset , then you have to load objects for that visible part and as you alloc new object you should store them in an array. As any image moves outside the visible area you should remove it from scrollview.
This way it will take less memory and you could load many images without getting memory warning.
You could follow this article to get some hint how to add and remove objects from scrollView
http://www.raywenderlich.com/10518/how-to-use-uiscrollview-to-scroll-and-zoom-content

Answer 3

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);

Answer 4

Thanks for your valuable answers. I fixed temporarily above issue using below code.
Bool isOddViewNo; //at .h file
isOddViewNo=YES; //at 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);
}
}
![I am Displaying three views with different sizes in each row of UIScrollview. Which is scrollable both horizontally and Vertically. Here is the screen shot taken from simulator][1]