I have a UIScrollView set up in IB. I am adding in a UIImageView to it in viewDidLoad method but it's not working. Here's my code:
- (void)viewDidLoad {
[super viewDidLoad];
UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:imageName]];
[scrollView addSubview:imageView];
[scrollView setContentSize:[imageView frame].size];
[imageView release];
}
I NSLog-ed imageView and it's not null. What am I doing wrong? Thanks.
EDIT: The screen is just blank. There's nothing there.
It sounds like your UIScrollView isn't hooked up. Is the outlet for scrollview valid? Log scrollView to verify.
Related
Currently I'm facing a problem, I would like to perform action when the UIImageView on my UITableViewCell had been tapped.
Question: How could I do it? Could any one show me the code, or any tutorial?
Thanks in advance!
This is actually easier than you would think. You just need to make sure that you enable user interaction on the imageView, and you can add a tap gesture to it. This should be done when the cell is instantiated to avoid having multiple tap gestures added to the same image view. For example:
- (instancetype)initWithCoder:(NSCoder *)aDecoder
{
if (self = [super initWithCoder:aDecoder]) {
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(myTapMethod:)];
[self.imageView addGestureRecognizer:tap];
[self.imageView setUserInteractionEnabled:YES];
}
return self;
}
- (void)myTapMethod:(UITapGestureRecognizer *)tapGesture
{
UIImageView *imageView = (UIImageView *)tapGesture.view;
NSLog(#"%#", imageView);
}
Try this
//within cellForRowAtIndexPath (where customer table cell with imageview is created and reused)
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleImageTap:)];
tap.cancelsTouchesInView = YES;
tap.numberOfTapsRequired = 1;
[imageView addGestureRecognizer:tap];
// handle method
- (void) handleImageTap:(UIGestureRecognizer *)gestureRecognizer
{
RKLogDebug(#"imaged tab");
}
make sure u have....
imageView.userInteractionEnabled = YES;
you can use a customButton instead UIImageView
A tap gesture recogniser can be very memory hungry and can cause other things on the page to break. I would personally reconmend you create a custom table cell, insert a button into the custom cell frame and in the tableview code set the self.customtablecell.background.image to the image you want. This way you can assign the button an IBaction to make it push to whatever view you want.
Use ALActionBlocks to action in block
__weak ALViewController *wSelf = self;
imageView.userInteractionEnabled = YES;
UITapGestureRecognizer *gr = [[UITapGestureRecognizer alloc] initWithBlock:^(UITapGestureRecognizer *weakGR) {
NSLog(#"pan %#", NSStringFromCGPoint([weakGR locationInView:wSelf.view]));
}];
[self.imageView addGestureRecognizer:gr];
So I've read this post
But it doesn't seem to deal with the issue of making the background NOT tint to a semi-transparent. I want the content behind the menu with buttons to be clearly visible. Is this even possible?
This is what I have currently
WPSActionSheet *actionSheet = [[WPSActionSheet alloc] initWithCompletion:completion];
[actionSheet setTitle:#""];
[actionSheet addButtonWithTitle:#"Take Photo"];
[actionSheet addButtonWithTitle:#"Choose from Library"];
[actionSheet addButtonWithTitle:#"Skip This Step"];
[actionSheet setCancelButtonIndex:2];
[actionSheet showInView:[self view]];
which shows this
UIActionSheet will always show the "tinted background". There is no way around this. You can however create your own version of the UIActionSheet using a UIView.
Just set the alpha and opaque property of UIActionSheet with delegate method -
(void)willPresentActionSheet:(UIActionSheet *)actionSheet
and it will be visible as you want.
If you want to make background of UIActionSheet transparent you can subclass it and change layoutSubviews
- (void)layoutSubviews
{
[super layoutSubviews];
UIImage* image;
CGSize size = self.frame.size;
UIGraphicsBeginImageContext(size);
image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
[[self layer] setContents:(id)image.CGImage];
}
To add some custom background just add following code to layoutSubviews:
CGRect frame = self.frame;
frame.origin = CGPointZero;
UIImageView* bg = [[UIImageView alloc] initWithFrame:frame];
bg.image = [UIImage imageNamed#"YOUR/IMAGE/NAME"];
[self addSubview:bg];
[self sendSubviewToBack:bg];
Also you can do all those actions in delegate method
- (void)willPresentActionSheet:(UIActionSheet *)actionSheet
simply replacing self to actionSheet.
I had the same problem and found a workaround. The UIActionSheet's superview contains a UIView that is used for the tinting. So you can remove the tinting by setting the opacity of this view's layer to 0.
- (void)willPresentActionSheet:(UIActionSheet *)actionSheet {
NSArray *subviews = actionSheet.superview.subviews;
UIView *tintView = [subviews objectAtIndex:0];
[tintView.layer setOpacity:0.0];
}
I've a sample project, where I have created a custom UIWebView named WebView. They are added to the view in a UIViewController. Two WebView's are initialized in the viewDidLoad and added to an array list. The first one is added as subview på self.view. The Storyboard contains a UIBarButton, and when this is tapped, the second WebView is added as subview to the self.view.
- (void)viewDidLoad
{
[super viewDidLoad];
WebView *webView1 = [[WebView alloc] initWithFrame:self.view.bounds];
WebView *webView2 = [[WebView alloc] initWithFrame:self.view.bounds];
self.webViews = [NSArray arrayWithObjects: webView1, webView2, nil];
UIWebView *webView = [self.webViews objectAtIndex:0];
[self.view addSubview:webView];
[webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:#"http://m.google.com/"]]];
}
Here is the implementation of the WebView where a toolbar is added to the bottom (-50px) of the view:
#implementation WebView
- (void) initToolbar {
UIToolbar *toolbar = [UIToolbar new];
toolbar.barStyle = UIBarStyleBlackTranslucent;
toolbar.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleTopMargin;
[toolbar sizeToFit];
toolbar.frame = CGRectMake(0, self.frame.size.height-80, 320, 30);
[self addSubview:toolbar];
}
- (id)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
if (self) {
self.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
[self initToolbar];
}
return self;
}
#end
The problem is, that the toolbar does not have the same position in the two views (they could be positioned like the first one). Why are they not positioned equally?
You can download the small sample project here:
http://uploads.demaweb.dk/UIWebView.zip
My notes: As mentioned, the two WebView's are currently initialized in the viewDidLoad. If I instead wait and first initialize then when I need them, it seems to work as expected.
The thing here is that self.frame.size.height on viewDidLoad is not the same when you initialize it via the button click. If you add the UIWebView directly in viewDidLoad, the UINavigationBar of your UINavigationController is not loaded yet and the frame of self.view is 'perceived' to be (not really, because it is) larger.
This explains the difference of 40.0 (?) points.
One possible solution to this problematic behaviour is to initialize and add (at least the first) instance of UIWebView in the viewWillAppear:animated method. (UIViewController does already implement this method)
I am trying to make clickable UIImage, where the user can click it then it'll animate...
i am working with the UIScrollVIew that's why i used the UITapGesture instead of touchesBegan, and it seems that UIGestureRecognizer is not compatible with UIImage...
am i right?
i keep receiving this error message
receiver type 'UIImage' for instance message does not declare a method
with selector 'addGestureRecognizer'
is there any other way?
You have to add TapGesture in UIImageView not UIImage
imgView.userInteractionEnabled = YES;
UITapGestureRecognizer *tapGesture1 = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(tapGesture:)];
tapGesture1.numberOfTapsRequired = 1;
[tapGesture1 setDelegate:self];
[imgView addGestureRecognizer:tapGesture1];
[tapGesture1 release];
You can response to the tap with the defined selector and do stuff there
- (void) tapGesture: (id)sender
{
//handle Tap...
}
You have to add the gesture to UIImageView, not UIImage
You can simply add a TapGestureRecognizer to a UIImageView. You have to use a UIImageView because gesture recognizer are only allowed to be added to views.
UIView *someView = [[UIView alloc] initWithFrame:CGRectZero];
UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(tapAction:)];
tapRecognizer.numberOfTapsRequired = 1;
[someView addGestureRecognizer:tapRecognizer];
You can response to the tap with the defined selector and do stuff there
- (void)tapAction:(UITapGestureRecognizer *)tap
{
// do stuff
}
Try with UIButton instead of UIIMage and make the UIButton type custom. And on clicking the same you can show the animation.
How can I use UIScrollView? please give me a simple example with one scrolling image?
This will get you an insight of the UIScrollView control:
Learning the basics of UIScrollView
Referenced from UIScrollView Tutorials
Some good samples with the basic functionalities covered
http://halmueller.wordpress.com/2008/10/08/a-very-simple-uiscrollview-demo/
http://developer.apple.com/iphone/library/samplecode/Scrolling/index.html
http://www.vimeo.com/1642150
http://jonathanwatmough.com/2008/12/implementing-tap-to-zoom-in-uiscrollview-on-an-iphone/
http://cocoawithlove.com/2009/01/multiple-virtual-pages-in-uiscrollview.html
Not to mention:
https://stackoverflow.com/search?q=UIScrollView
This can be one example. Basically we create a scrollview, set its frame, add content as a subview, and then set the content size. The image (iphone.png) below is bigger than the iphone screen so that we can scroll it.
UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 20, 320, 460)];
UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"iphone.png"]];
[scrollView addSubview:imageView];
[imageView release];
scrollView.contentSize = CGSizeMake(imageView.image.size.width, imageView.image.size.height);
[window addSubview:scrollView];
[scrollView release];
You can use below code to add UIScrollView on yourView :-
[self.ScrollView setContentSize:(CGSizeMake(self.view.frame.size.width, self.view.frame.size.height))];
Step:1
Create a UiScrollView,
#interface ViewController : UIViewController
#property (strong, nonatomic) IBOutlet UIScrollView *MyScrollView;
#end
Step2:
In your ViewController.m,
[self.MyScrollView setContentSize:(CGSizeMake(self.view.frame.size.width, self.view.frame.size.height))];
Add UIImageView in to UIScrollView.
then,
Use
imageView.image = [UIImage imageNamed:#"image1.png"];
imageView.frame = CGRectMake(0.0, 0.0, imageView.image.size.width, imageView.image.size.height);
scrollView.contentSize = CGSizeMake(imageView.image.size.width, imageView.image.size.height);