what is the best way for horizontal scrolling of image in iphone sdk. Image has to be get from web server something like lazy loading?
please help me.
Here is my suggestion:
First, set fixed size for your UIScrollView.
scroll.size = ... // your size
Next, determine width and height for contentSize of your scroll. Fix the height. the width is the value changeable. After each lazy image is loaded successfully, adjust the width.
Assume, all the image have the same height. Then, each time when there's an image is loaded, the code is:
(in the below code, I assume that the new image is appended. In your case, you can configure properly for your need)
float oldScrollWith = scroll.contentSize.width
// creat new_image_view (UIImageView)
// configure it to display in the scroll
...
new_image_view.frame = CGRectMake(oldScrollWidth, 0, imageViewWidth, fixed_image_height)
// append the new view to the scroll
float newScrollWidth = oldScrollWidth + new_image_view.frame.size.width // re-calculate the width for the contentSize of scroll
scroll.contentSize = CGSizeMake(newScrollWidth, fixed_image_height);
[scroll addSubview:new_image_view];
Related
I've done quite a bit of looking into this but have been unsuccessful in finding a solution.
I have a UIScrollView called scrollView inside of UIView. I'm using this scrollView in pagingEnabled mode. Inside of scrollView, I have 3 different views created programmatically. Inside of these 3 different views, I have a bunch of stuff(UILabel,UITextView etc.). All of the views contents are dynamic and determined at runtime.So, i really don't know scrollView.contentSize. If i give the content size of this scrollView,Sometimes ,I have a screen with white blank at the botton of the screen when user scrolls down. My question is : Can i set the content size dynamically for each single page of this scrollView? For example,for page 1 :
self.scrollViewNews.contentSize = CGSizeMake(constant1,constant2);
And set something else for page 2 as well .
I think you're confused about contentSize vs the paging size. The paging size is always the size of the scrollView bounds, and isn't a property you can otherwise set. That is, when you swipe left/right it will "page" by the width of the scrollview.
contentSize is the size of the virtual bounding box of all the subviews within the scrollview. This only serves to limit how far the scrollview will scroll, and for paging, how many times it will page, i.e. contentSize.width / bounds.size.width.
Assuming the scrollView isn't zoomed in/out (zoomScale = 1.0) then you need to position and size your subviews on the virtual 'page boundaries'. They can take up the full page boundary (be sized to match scrollview.bounds) or be inset. If you have some content that is larger/smaller then you'll have to decide if you want to change the scale of that content or size it up/down within the page bounds.
Yes you can dynamically set the content size of the scrollView. Also You can use this method:
self.scrollViewNews.contentSize = CGSizeMake(constant1,constant2);
Nothing wrong this method. You are seeing the blank space at bottom because you ares setting the height of the scrollView's contentSize to a larger value than it's content. That's the issue. Adjust the height according to the contents, blank space will go.
please, try to get the actual content size from the current content.
the content must be some inherited class from the UIView and it has a frame.size.width and frame.size.height property.
you can use those to set the contentSize of your UIScrollview for the current content at that time when you add the content to the UIScrollView.
Yeah. You can set the scrollView size dynamically through
scroller.contentSize = CGSizeMake(1650, 2000);
You can use the following property to set the dynamic frame for each pages
[urScrollView scrollRectToVisible:frame animated:YES];
if you are using pagingEnabled = YES for your scrollview
The below UIScrollViewDelegate delegate will adjust the page and content
-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{
int page = urScrollView.contentOffset.x/urScrollView.frame.size.width;
pageControl.currentPage = page;
}
//pager action
- (IBAction)changePage:(id)sender{
int page = pageControl.currentPage;
CGRect frame = urScrollView.frame;
frame.origin.x = frame.size.width * page;
frame.origin.y = 0;
[urScrollView scrollRectToVisible:frame animated:YES];
}
please look at this sample app
Try out this.
- (void)viewDidLoad
{
float sizeOfContent = 0;
UIView *lLast = [scrollView.subviews lastObject];
NSInteger wd = lLast.frame.origin.y;
NSInteger ht = lLast.frame.size.height;
sizeOfContent = wd+ht;
scrollView.contentSize = CGSizeMake(scrollView.frame.size.width, sizeOfContent);
}
I have an Image and an ImageView, the ImageView occupies the whole screen and I want to resize the image to fit the ImageView. The ImageView is inside a ScrollView with only vertical scroll bar enabled, which means the Image should be resized with maximum width equal to that of the screen(ImageView), in the mean time keeping the ratio, not constrained on the resized height. The ImageView's height will fit with resized Image, if the height exceeds the height of the screen we can use the scroll bar to see it.
So I want suggestions on:
1) How I can resize an Image with a fixed width if the original width is less than the desired one, no resize is required. No constraint on height.
2) How I can make the ImageView fit the height of the Image automatically?
First, you can calculate the new image's height by yourself.
(if, image's size = (300,200), imageView's width = 320, the new image's height = 200*(320/300))
Then, from this thread The simplest way to resize an UIImage?
You can resize the Image with new width and height.
Total soultion:
UIImage* i= /* original image */;
UIImage* j =[self imageWithImage:i scaledToSize:newSize]; //new Image
[theImageView setImage:j];
(And this code also works fine with iOS 4.x)
I've a screen in an app I'm coding structured like this:
View
ScrollView
View
label 1
label 2
label 3
View
UIImageView
WebView
When loaded it adds some html string into the Web View and as the whole content (labels,image,html content) is longer than the screen height, I would like to allow the screen to scroll down/up when user is reading content. This is why I added the SrollView but nothing scroll!
I also did is scroll_view.contentSize = [self.view bounds].size; but it didn't work
Any idea on how to do this ?
Thx in advance for helping,
Stephane
By default UIScrollView is set a contentSize equal to its frame size. If you want it to be scrollable, you have to explicitly set the contentSize.
scrollView.contentSize = CGSizeMake(_width, _height);
Mostly you won't be knowing the actual contents size while you create the scroll view. You can assign the contentSize after adding the UIWebview(as web view is the last view in your scroll view). You can do it like this,
// Add other views to scrollView
// Create and configure webView
[scrollView addSubview:webView];
float _width = scrollView.contentSize.width; // No change in width
float _height = CGRectGetMaxY(webView); // Returns (webView.frame.origin.y + webView.frame.size.height)
scrollView.contentSize = CGSizeMake(_width, _height);
Below code u observe Here "Height" declare Dynamically as your Requirement
EXample :
if([Myarray length]>25)
{
myString = [myString stringByAppendingFormat:#"<tr><th align=\"left\">%#</tr>",str_owes ];
height += 50;
}
webview.frame=CGRectMake(25, 153, 420, height);
[webview loadHTMLString:myString baseURL:nil];
scrollview.contentSize=CGSizeMake(0, webview.frame.origin.y+webview.frame.size.height+50);
You need to set the UIScrollView's contentSize to be the size of the two views + the UIWebView combined.
You will also need to make sure that the UIWebView if of the right size and then turn scrolling off, as you may get scrolling issues otherwise (one scroll view inside another).
More info: http://developer.apple.com/library/ios/#DOCUMENTATION/UIKit/Reference/UIScrollView_Class/Reference/UIScrollView.html
I have a scrollView which consists of 3 textViews, buttons and labels in a detailView. i am using 3 text view because i need different fonts for my view title, date and description. problem is sometimes description is long and sometimes its small and same thing with headings. then view doesn't loog good at all because of alot of empty spaces between title and description. Is it possible to set the size of textView and scroll view dynamically or is there any better approach to solve this problem. thanx in advance
You need to adjust the frames of the text views to match their respective contentSizes (see the top answer here: How do I size a UITextView to its content? on how to do that, uses the contentSize property of the textview), then you adjust the contentSize of the scrollView based on the frames of all the controls.
Assuming your textviews are placed consecutively vertically (just adjust the code if there is spacing, etc.):
// (first adjust each text view's frame per the linked answer)
...
// then adjust the frames of the content
CGRect topTextViewFrame = topTextView.frame;
CGRect middleTextViewFrame = middleTextView.frame;
middleTextViewFrame.origin.y = topTextViewFrame.origin.y + topTextViewFrame.size.height;
middleTextView.frame = middleTextViewFrame;
CGRect bottomTextViewFrame = bottomTextView.frame;
bottomTextViewFrame.origin.y = middleTextViewFrame.origin.y + middleTextViewFrame.size.height;
// then adjust your other controls based on these frames, for example:
CGRect myButtonFrame = myButton.frame;
myButtonFrame.origin.y = bottomTextViewFrame.origin.y + bottomTextViewFrame.size.height;
// finally adjust the contentSize of the scrollview assuming the button is the bottom element
CGSize csize = myScrollView.contentSize;
csize.height = myButtonFrame.origin.y + myButtonFrame.size.height;
myScrollView.contentSize = csize;
You could set the size of the frame to be dependent on the character length by setting the frame at the onset to be:
CGRectMake (0.0, 0.0, [yourString count]*10, 30.0);
This is what I did when I had a UIPopover come up with a variable name.
I have a UITextView and I would like to only allow it to be scrollable horizontally only.
Basically when the UITextView word-wraps I want the user to have to scroll horizontally to be able to view the rest of the contents.
You can set the content size of the text view to the height of the view. Just make sure the width of the content extends past the width of the textView's frame or else it won't scroll.
// UITextView* myTextView: gets declared somewhere...
// The text view (subclass of a UIScrollView) won't go past its content size
[myTextView setContentSize:CGSizeMake(width, myTextView.frame.size.height)];
// Just in case, if you don't want your user bouncing the view up/down
[myTextView setAlwaysBounceVertical:NO];
I hope that's what you were looking for.
The solution is to turn off all the scroll options on the UITextView itself, then embed it in another UIScrollView. You can get actual code by searching on this term "DualScrollTextView" in google. You cannot force changes to contentSize to accomplish this - many have tried.
This worked for me:
self.dishNameLabel.text = #"Here is some very longgggg text to test with";
float width = ceil([self.dishNameLabel.text sizeWithAttributes:#{NSFontAttributeName: [UIFont fontWithName:#"WorkSans-SemiBold" size:15.0]}].width);
self.dishNameLabel.frame = CGRectMake(self.dishNameLabel.frame.origin.x, self.dishNameLabel.frame.origin.y, width, self.dishNameLabel.frame.size.height);
self.dishNameScrollView.contentSize = CGSizeMake( width, self.dishNameScrollView.frame.size.height);
Of course, you will have to replace your text and font with your respective specs