I searched here a lot but I am not able to do it.
Basically, I want to scroll below i.e in downward direction to check whether a coupon image which I am using is available or not. This is initiated by a button click.
This is how I create the scroll view:
UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 20, 320, 440)];
scrollView.contentSize = CGSizeMake(320,500);
[self.view addSubView:scrollView];
-(void)movedown
{
[scrollView setContentOffset:CGPointMake(0,500) animated:YES];
}
it can be used to move down as upto 500 in y direction as u desired for 500 from scrollView.contentSize = CGSizeMake(320,500);
- (IBAction) yourBtnInScrollViewPressed : (id) sender
{
[yourScrollView scrollRectToVisible:CGRectMake(x, y, yourScrollView.frame.size.width, yourScrollView.frame.size.height) animated:YES];
}
You can change the UIScrollView position as required on button pressed.
- (IBAction) yourBtnInScrollViewPressed : (id) sender
{
[yourScrollView setContentOffset:CGSizeMake(x,y)];
//set Your x and Y coordinates as you required.
}
You can change the currently codinates of your UIScrollView.
I made a pretty decent post about automagically scrolling UIScrollViews. Maybe it can help you out a bit.
UITableView scroll smooth with certain speed?
Good luck ;)
-(IBAction)scrolldown
{
[scrollView setContentOffset:CGSizeMake(100,30)]; //change 30 if you want to see below images.
}
Related
I have UIScrollView on which I am using 2 UIButtons. UIScrollView initial frame is (0,0,768,1024). I want when I click on first button the UIScrollView y-cordinate position will be 500, means it will scrolldown 500 positions below to its actual position.
And when I click second Button which Will show on UIScrollView, Position Y-cordinate of UIScrollView y=535, then UIScrollView Move up to Position y= 0 again.
First button click UIScrollView y = 500
Second button click UIScrollView y = 0
Any hints from experts would be very welcome.
Maybe you do not want to change the frame of the scroll view (this would just displace the whole view), but the contentOffset. This can be animated, too.
CGPoint offset = scrollView.contentOffset;
offset.y += 500;
[scrollView setContentOffset:offset animated:YES];
This may solve ur pbm
-(IBAction) clickfirstbutton
{
[scrollview setContentOffset:CGPointMake(0, 500)) animated:TRUE];
}
-(IBAction) clicksecondbutton
{
[scrollview setContentOffset:CGPointMake(0, 0) animated:TRUE];
}
If u don't want animations use
[scrollview setContentOffset:CGPointMake(0, 0) animated:FALSE];
I need in my project to make the scroll an image continuously, ie from the bottom of the image once scrolled by continuing to scroll to the top should start from the base and so on, in a sort of loop, how can I do to do this?
Thanks
In this example i am taking total 5 images
- (void)viewDidLoad {
[super viewDidLoad];
// add the last image (image4) into the first position
[self addImageWithName:#"image4.jpg" atPosition:0];
// add all of the images to the scroll view
for (int i = 1; i < 5; i++) {
[self addImageWithName:[NSString stringWithFormat:#"image%i.jpg",i] atPosition:i];
}
// add the first image (image1) into the last position
[self addImageWithName:#"image1.jpg" atPosition:5];
scrollView.contentSize = CGSizeMake(320, 2496);
[scrollView scrollRectToVisible:CGRectMake(0,416,320,416) animated:NO];
}
- (void)addImageWithName:(NSString*)imageString atPosition:(int)position {
// add image to scroll view
UIImage *image = [UIImage imageNamed:imageString];
UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
imageView.frame = CGRectMake(0,position*416,320, 416);
[scrollView addSubview:imageView];
[imageView release];
}
implement delegate method
- (void)scrollViewDidEndDecelerating:(UIScrollView *)sender {
NSLog(#"%f",scrollView.contentOffset.y);
// The key is repositioning without animation
if (scrollView.contentOffset.y == 0) {
// user is scrolling to the left from image 1 to image 4
// reposition offset to show image 4 that is on the right in the scroll view
[scrollView scrollRectToVisible:CGRectMake(0,1664,320,416) animated:NO];
}
else if (scrollView.contentOffset.y == 2080) {
// user is scrolling to the right from image 4 to image 1
// reposition offset to show image 1 that is on the left in the scroll view
[scrollView scrollRectToVisible:CGRectMake(0,416,320,416) animated:NO];
}
}
I gives the two reference link for the automatically scroll the scroll view where the you can grap the source code also and implement into your project it's amazing funcationality
1) Automatically scroll the scroll view
2) As par your requirement created post of like wise gallery.
May this post is useful for you.
Happy codeing
Thanks and Regards,
#Samuel
I have a UITextView inside of a UIScrollView that is configured offscreen when the code below runs in my ViewController's viewDidLoad. Unfortunately, if the "eventDetails" text is particularly long nothing is displayed inside the UITextView until I interact with it (e.g click inside and drag for example).
My question: How to have it so the text is displayed in the UITextView WITHOUT forcing the user to interact with the UITextView first?
Here is the code:
UITextView *txtDetails = [[UITextView alloc] initWithFrame:CGRectMake(-4, yOffset, page3ScrollView.frame.size.width, 0)];
[txtDetails setEditable:NO];
[txtDetails setScrollEnabled:NO];
[txtDetails setFont:[UIFont systemFontOfSize:12]];
[txtDetails resizeAndSetTextWithMaxSize:CGSizeMake(txtDetails.frame.size.width, 999999999) forText:eventDetails withAdditionalHeightOf:16.f];
[page3ScrollView addSubview:txtDetails];
CGRect frame = txtDetails.frame;
frame.size.height = [txtDetails contentSize].height;
txtDetails.frame = frame;
[page3ScrollView setContentSize:CGSizeMake(page3ScrollView.frame.size.width, txtDetails.frame.origin.y + txtDetails.frame.size.height)];
Thanks
I was able to get this working by setting the UITextView's text ONLY when needed (e.g. is about to come on screen). Below is the relevant code:
- (void)scrollViewDidEndDecelerating:(UIScrollView *)sv
{
if (sv == scrollView) [self updatePagedView];
}
- (void)updatePagedView
{
int currentPage = pageControl.currentPage;
// *** loadDetailsPage3 is where I set the text ***
if (currentPage == 2) {
[self loadDetailsPage3];
}
}
If anyone has a better solution or needs more explanation just hit me up in the comments.
I've had the same issue and it's taken me several hours to find a suitable fix for it... Here's what I came up with...
-(void)DidBecomeActive {
if (!DidUpdateBounds) {
DidUpdateBounds = true; // instance variable set to false on load
NSString *oldtext = uiTextView.text;
//The trick is (1) removing it from it's superview
// (2) resetting it's 'text' property
// (3) re-adding it to the view WHILE it's on-screen.
[uiTextView removeFromSuperview];
uiTextView.text = oldtext;
[self.view addSubview:uiTextView];
[self.view setNeedsDisplay];
}
}
I'm using CoreAnimation to switch to this view. So right before I execute that code, I call this
//The 0,-300,480,300 is bounds of the UIView my offscreen UITextview is on
[self.view.layer setBounds:CGRectMake(0, -300, 480, 300)];
// SetNeedsDisplay, then call my method above to
//FORCIBILY redrew the UITextView while it's effectively on-screen
[self.view setNeedsDisplay];
[TextLogVC DidBecomeActive];
//CoreAnimation then goes here
This solves the issue. After setting the layer.bounds it redraws the control(UITextView) and it thinks it's onscreen. Then CoreAnimation takes care of animating from my current UIView to the new UIView and all of the text in the uiTextView is displayed throughout the animation.
Looks like the views that you are setting up are not refreshed.
And when you interact with the views then they are refreshed and your changes are rendered to the display...
Try adding [txtDetails setNeedsDisplay]; [page3ScrollView setNeedsDisplay]; after your code in viewDidLoad.
If it will help then maybe we'll find some more elegant solution...
I have seen this question being addressed several times here at SO, e.g Problem with UIScrollView Content Offset, but I´m still not able to solve it.
My iphone app is basically a tab bar controller with navigation bar. I have a tableview controller made programmatically and a DetailViewController that slides in when I tap a cell in my tableview controller.
The DetailViewController is made in IB and has the following hierarchy:
top view => UIScrollView => UIView => UIImage and a UITextField.
My goal is to be able to scroll the image and text field and this works well. The problem is that my UIScrollView always gets positioned at the bottom instead at the top.
After recommendations her at SO, I have made my UIScrollView same size as the top view and instead made the UIView with the max height (1500) of my variable contents.
In ViewDidLoad I set the contentSize for the UIScrollView (as this is not accessible from IB):
- (void)viewDidLoad {
[scrollView setContentSize:CGSizeMake(320, 1500)];
[scrollView setContentOffset:CGPointMake(0, 0) animated:YES];
NSLog(#"viewDidLoad: contentOffset y: %f",[scrollView contentOffset].y);
}
Specifically setting the contentOffset, I would expect my scrollView to always end up at the top. Instead it always go to the bottom. It looks to me that there is some autoscrolling beyond my control taking place after this method.
My read back of the contentOffset looks OK. It looks to me that there may be some timing related issues as the scrolling result may vary whether animation is YES or NO.
A ugly workaround I have found is by using this delegate method:
- (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrView {
NSLog(#"Prog. scrolling ended");
[scrollView setContentOffset:CGPointMake(0, 0) animated:YES];
}
This brings my scrollview to top, but makes it bounce down and up like a yo-yo
Another clue might be that although my instance variables for the IBOutlet are set before I push the view controller, the first time comes up with empty image and textfield:
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
if (!detailViewController) {
detailViewController = [[DayDetailViewController alloc] init];
}
// Pass dictionary for the selected event to next controller
NSDictionary *dict = [eventsDay objectAtIndex:[indexPath row]];
// This method sets values for the image and textfield outlets
[detailViewController setEventDictionary:dict];
// Push it onto the top of the navigation controller´s stack.
[[self navigationController] pushViewController:detailViewController animated:NO];
}
If I set animation to YES, and switch the order of the IBOutlet setting and pushViewController, I can avoid the emptiness upon initialization. Why?
Any help with these matters are highly appreciated, as this is really driving me nuts!
Inspired of Ponchotg´s description of a programmatically approach, I decided to skip interface builder. The result was in some way disappointing: The same problem, with the scrollview ending up in unpredictable positions (mostly at bottom), persisted.
However, I noticed that the scroll offset error was much smaller. I think this is related to the now dynamic (and generally smaller) value of ContentOffset. After some blind experimenting I ended up setting
[textView setScrollEnabled:YES];
This was previously set to NO, as the UITextView is placed inside the scrollview, which should take care of the scrolling. (In my initial question, I have erroneously said it was a UITextField, that was wrong)
With this change my problem disappeared, I was simply not able to get into the situation with scrollview appearing at bottom anymore in the simulator! (At my 3G device I have seen a slight offset appear very seldom, but this is easily fixed with scrollViewDidEndScrollingAnimation delegate described previously ).
I consider this as solved now, but would appreciate if anyone understand why this little detail messes up things?
OK! i have a question before i can give a correct answer.
Why are you using a UIView inside the Scrollview?
You can always only put your UIImageView and UITextField inside the UIScrollView without the UIView
and set the contentSize dynamically depending on the size of the text.
to give you an example how i do it:
int contSize = 0;
imageView.frame = CGRectMake(10, 0, 300, 190);
imageView.image = [UIImage imageNamed:#"yourimage"];
contSize = 190 //or add extra space if you dont want your image and your text to be so close
[textField setScrollEnabled:NO];
textField.font = [UIFont systemFontOfSize:15];
textField.textColor = [UIColor grayColor];
textField.text = #"YOUR TEXT";
[textField setEditable:NO];
textField.frame = CGRectMake(5, contSize, 310, 34);
CGRect frameText = textField.frame;
frameText.size.height = textField.contentSize.height;
textField.frame = frameText;
contSize += (textField.contentSize.height);
[scrollView setScrollEnabled:YES];
[scrolView setContentSize:CGSizeMake(320, contSize)];
In the above example I first create an int to keep track of the ysize of my view then Give settings and the image to my UIImageView and add that number to my int then i give settings and text to my UITextField and then i calculate the size of my text depending on how long is my text and the size of my font, then add that to my int and finally assign the contentSize of my ScrollView to match my int.
That way the size of your scrollview will always match your view, and the scrollView will always be at top.
But if you don't want to do all this, you can allways just:
[scrollView setContentOffset:CGPointMake(0, 0) animated:NO];
at the end of the code where you set your image and your text, and the NOto avoid the bouncing.
Hope this helps.
I am pretty new to iphone programming. I just started about a month ago and have only been tinkering with small tutorial type applications but anyways, here is my question.
I currently have a UIScrollView thats scrollable and zoomable, that loads a UIImageView subview, and i want to add in some controls(UIButtons) over the image view but when i zoom in and out the whole group(the buttons and the image) zoom togeather.
If I add the UIButtons to my UIScrollView and zoom, the image zooms and the buttons stay in origional place
If I add the UIButtons to my UIImageView they zoom correctly but arent buttons anymore. IE they lose their interactivity.
Later ill add lots of buttons into an array and add them.
I would appreciate any help i can get
This is part of my mainViewController.m:
- (void)viewDidLoad
{
[scrollView2 setBackgroundColor:[UIColor blackColor]];
[scrollView2 setCanCancelContentTouches:NO];
scrollView2.clipsToBounds = YES; // default is NO, we want to restrict drawing within our scrollview
scrollView2.indicatorStyle = UIScrollViewIndicatorStyleWhite;
scroll2ImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"bigNH.jpg"]];
[scrollView2 addSubview:scroll2ImageView];
[scrollView2 setContentSize:CGSizeMake(scroll2ImageView.frame.size.width, scroll2ImageView.frame.size.height)];
scrollView2.minimumZoomScale = .5;
scrollView2.maximumZoomScale = 3;
scrollView2.delegate = self;
[scrollView2 setScrollEnabled:YES];
UIButton *myButton = [UIButton buttonWithType:UIButtonTypeCustom];
CGRect newSize = CGRectMake(658, 435, 50, 50); // position in the parent view and set the size of the button
myButton.frame = newSize;
[myButton setImage:[UIImage imageNamed:#"redStop.png"] forState:UIControlStateNormal];
// add targets and actions
[myButton addTarget:self action:#selector(buttonClicked:) forControlEvents:UIControlEventTouchUpInside];
// add to a view
[scroll2ImageView addSubview:myButton];
[redLineArray addObject:myButton];
[scroll2ImageView release];
}
This might not help and it is not what it appears that you want to do.
However, when I want buttons associated with a scrollview, I add a parent view, add the buttons to that view and also add the scrollview to that view. The button(s) and the scrollview would be siblings. This allows the user to scroll around the contents of the scrollview, while insuring that the buttons are always in view.
-isdi-
By default, UIImageView has userInteraction disabled. Have you changed this?
Also, I would be really uneasy adding subviews to an UIImageView, it's really meant to hold one image. It would be better to create a normal UIView and add the UIButtons and UIImageView to that. It's very easy to control the ordering so that the buttons appears on top of the image.
P.S. Just to make your life easier, instead of :
[scrollView2 setContentSize:CGSizeMake(scroll2ImageView.frame.size.width, scroll2ImageView.frame.size.height)];
You can use :
[scrollView2 setContentSize:scroll2ImageView.frame.size];
Make a single view to contain all your zoomable content (everything it would appear), and call it say contentView. Now place everything you want in that contentView, the imageView and all your buttons etc.
In your UIScrollView delegate place this: (Be sure to set the scrollView's delegate if you haven't already)
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
return self.contentView;
}
Only one view is allowed to zoom, but that one view can however contain other views that will scale because they're child views.
Also be sure to set the scrollView's contentSize value to the exact size of your zoomable contentView.