I was wondering how you would hide an image in Objective-C.
I know you can hide text or a button like this
StartGame.hidden = YES;
But when I try to do this with an image, i get an error.
Since UILabel, UIButton, UIControl and UIImageView are all childs from UIView they all have the hidden property to hide them.
So any instance of the of a view (or its childs) can be hidden by setting the hidden property to YES.
If your UIImageView is part of your viewcontroller it would make sense to make a property of it rather then just an variable, but I can not see your full code or error to say that the error might be found there.
Also property or variables should not start with a capital, its not in line with the Objective-C style.
UIImageView *ImageView=[[UIImageView alloc] initWithFrame:CGRectMake(x, y,width, height)];
[ImageView setImage:[UIImage imageNamed:#"image.png"]];
and to hide this image You just need to write
[ImageView setHidden:YES];
Related
I've put a UIButton inside a custom UIView and the button is not receiving any touch events (it doesn't get into the highlighted state, so my problem is not about being unable to wire up a touch inside up handler). I've tried both putting it into the XIB in Interface Builder, and also tried programatically adding the UIButton into the UIView seperately, both ended with no luck. All my views are inside a UIScrollView, so I first though UIScrollView may be blocking them, so I've also added a button programatically exactly the same way I add my custom view into UIScrollView, and the button worked, elimination the possibility of UIScrollView could be the cause. My View's hiearchy is like this:
The button is over the image view, and the front layer isn't occupying my button completely, so there's no reason for me not be physically interacting with the button. At my custom view's code side, I'm creating my view as such:
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
UIView *sub = [[[NSBundle mainBundle] loadNibNamed:#"ProfileView" owner:self options:nil] objectAtIndex:0];
[self addSubview:sub];
[sub setUserInteractionEnabled:YES];
[self setUserInteractionEnabled:YES];
CALayer *layer = sub.layer;
layer.masksToBounds = YES;
layer.borderWidth = 5.0;
layer.borderColor = [UIColor whiteColor].CGColor;
layer.cornerRadius = 30.0;
/*layer.shadowOffset = CGSizeZero;
layer.shadowRadius = 20.0;
layer.shadowColor = [[UIColor blackColor] CGColor];
layer.shadowOpacity = 0.8;
*/
}
return self;
}
I've tried all combinations of setUserInteractionsEnabled, and had no luck. (Yes, also set them to checked in Interface Builder too). I've also read in another question with a similar problem that I should try overriding 'canBecomeFirstResponder' to return 'YES' and I've also done that too. But the problem persists, I can't click the button. I've not given any special properties, settings to the button, it's just a regular one. My other objects in the view (labels below, image view behind the button etc.) are working properly without problems. What could be possibly wrong here?
Thanks,
Can.
UPDATE: Here is a quick reproduction of the problem: https://dl.dropbox.com/u/79632924/Test.zip
Try to run and click the button.
Looking at the test project, I believe your problem in the way you create TestView, you do not specify the frame for it, so basically the parent view is 0 size, and the subviews you see from XIB extending out of the parent view and thus do not get anything in responder chain.
You should either specify the frame when creating TestView, or adjust the frame after loading XIB file.
I have had this problem as well. The cause for me was that the UIButton superview frame was of height 0, so I believe that even though a touch was happening, it was not being passed down to the button.
After making sure that the button's superview took a larger rectangle as a frame the button actions worked.
The root cause for this problem on my side was a faulty auto layout implementation (I forgot to set the height constraint for the button's superview).
I've found the solution. I was initializing my custom view as:
MyView *view = [[MyView alloc] init];
I've initialized it instead with a frame of my view's size, and it started responding to events:
CGRect rect = CGRectMake(0,0,width,height);
MyView *view = [[MyView alloc] initWithFrame:rect];
Storyboard Solution
Just for anyone wanting a solution to this when using storyboards and constraints.
Add a constraint between the superview (containing the button) and the UIButton with an equal heights constraint.
In my case, I had selected embed UIButton in a UIView with no inset on the storyboard. Adding the additional height constraint between the UIButton and the superview allowed the UIButton to respond to touches.
You can confirm the issue by starting the View Debugger and visually confirm that the superview of the UIButton is not selectable.
(Xcode 11, *- Should also work in earlier versions)
I want to change the titleView of navigationBar with a regular text field. Then I want to set the textField size to fill the old "normal" titleView.
I can't seem to be able to do this in storyBoard. Dragging a text Field to the place where the navigation title View is doesn't work.
So I added stuff at
-(void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
PO(self.navigationItem.titleView);
CGRect theFrame= self.navigationItem.titleView.frame;
self.navigationItem.titleView=self.searchBar;
//self.searchBar.frame = theFrame;
while (false);
...
It's working with one cached. That PO is a macro that print the content of the object. Turns out at viewDidAppear, self.navigationItem.titleView is null.
So while I can display the searchBar, I cannot make the searchBar "fill" it's space because I do not know the space is.
I prefer not to hard code it because you know, things may change in the future.
So what should I do?
I once saw codes where rather than setting the self.navigationItem.titleView, you would simply add subview to it. The problem with this approach even on viewDidAppear, self.navigationItem.titleView is 0.
I added these codes:
CGRect theFrame= self.navigationItem.titleView.frame;
CGRect theFrame2 = self.searchBar.frame;
CGRect theFrame3 = self.navigationController.navigationItem.titleView.frame;
And, I do not know how to nslog structure value, however, theFrame and theFrame3 are all 0
You can try this inside viewWillAppear:
UIView *customTitleView = [[UIView alloc]initWithFrame:CGRectMake((320-210)/2, 0, 210, 50)];
customTitleView.backgroundColor = [UIColor clearColor];
//create your UITextField or UILabel or other view and add as subview of customTitleView
self.navigationItem.titleView = customTitleView;
I need to show an image, and above it some buttons that correspond to certain clickable areas of the image, the problem is that the image has zoom, and when i zoom the image, the buttons do not stay in the same place as the picture. The solution was to use the class ImageScrolView, used in the example of Apple PhotoScroller. The button appears exactly in the right place, regardless of zoom.
Just like the example, i use a ScrollView to display multiple images, these images are shown by class ImageScrollView.
This class declares one UIView in the .H file, but in the implementation file, the method that displays the image, convert the UIView into a UIImageView
imageView = [[UIImageView alloc] initWithImage: image];
then create my button and add to the imageView.
amazon = [UIButton buttonWithType: UIButtonTypeRoundedRect];
amazonia.frame = CGRectMake (92,240,109,142);
[amazon addTarget: self action: # selector (selectState :) forControlEvents: UIControlEventTouchUpInside];
[imageView addSubview: amazon];
My problem is that the button does not respond to button events, it appears in the right place and everything, but does not respond to button events.
Any ideas? Ideias on how to implement those clickable areas on the image are welcome too.
make sure to set imageView.userInteractionEnabled = YES!
Hope that helps.
The UITextFields in my app have placeholder text defined (in Interface Builder), and I cannot cause these fields to acquire focus (i.e. show the keyboard and allow editing) when I tap on the area occupied by the placeholder text. If I tap on the textfields in an area just outside the that of placeholder text (though still within the bounds of the textfiled itself), it acts as normal (i.e. the keyboard pops up and I can edit the content of the textfield). How can I fix this?
Thanks.
EDIT 1
Ok, I think I've got it. I'm also setting a blank view to the "leftView" property of these UITextFields. If I remove this, you can touch the UITextFields in the area of the placeholder text and it reacts as expected; I need this view for the leftView though. If you change the background color of this spacer view to red, you can see that it doesn't get in the way at all, so I don't know what's going wrong.
Why does this code cause this problem?
Thanks.
+(UIView*)getTextFieldLeftSpacerViewWithBackgroundColor:(UIColor*)backgroundColor andHeight:(CGFloat)height
{
UIView *leftWrapper = [[UIView alloc] initWithFrame:CGRectMake(0.0f, 0.0f, 8.0f, height)];
leftWrapper.autoresizingMask = UIViewAutoresizingNone;
[leftWrapper setOpaque:YES];
if(backgroundColor){leftWrapper.backgroundColor = backgroundColor;}
else{leftWrapper.backgroundColor = [UIColor clearColor];}
return [leftWrapper autorelease];
}
+(void)setTextFieldLeftSpacerForTextFieled:(UITextField*)textField
{
if(textField)
{
UIView *spacer = [MYViewController getTextFieldLeftSpacerViewWithBackgroundColor:nil andHeight:textField.bounds.size.height];
textField.leftView = spacer;
textField.leftViewMode = UITextFieldViewModeAlways;
}
}
Just ran into the same problem and didn't want to subclass, just had to use :
leftWrapper.userInteractionEnabled = NO;
I abandoned this approach. Instead of using an invisible view to offset the text, I opted to subclass UITextField and provide offset CGRects for the bounds of the text within theUITextField. The following SO post was very helpful:
Indent the text in a UITextField
I have a button in a tableView Cell that I need to respond to touch events. Normally this would easily be solved by
[cell.playButton addTarget:self action:#selector(playButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
inside of -tableView:cellForRowAtIndexPath:
The problem I am having is that my button is inside of a custom UITableViewCell subclass and is also the subview of a view that I am creating inside of that class..
for example:
UIView *view = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 320, 44)];
self.theView = view;
[self addSubview:view];
[view release];
UIButton *playButton = [UIButton buttonWithType:UIButtonTypeCustom];
playButton.frame = CGRectMake(5, 5, 100, 30);
[playButton setImage:[UIImage imageNamed:#"button_playvid.png"] forState:UIControlStateNormal];
[playButton setImage:[UIImage imageNamed:#"button_playvid_active.png"] forState:UIControlStateHighlighted];
self.playButton = playButton;
[self.theView addSubview:playButton];
When the button is a subview of a view that I create within the custom UITableViewCell then the cell is highlighted instead of the button being pressed so the target that I setup in -tableView:cellForRowAtIndexPath is never called. Not sure why.. any help?
Thanks,
Joel
PS. I realize that there probably isn't a practical reason to create a background view exactly like this since there already is one. This is just example code that I'm using to explain a problem I'm having.. :D
Thanks for Looking!
The UIView you are adding is actually a UIImageView. From the docs:
New image view objects are configured to disregard user events by default. If you want to handle events in a custom subclass of UIImageView, you must explicitly change the value of the userInteractionEnabled property to YES after initializing the object.
I think that either userInteractionEnabled cascades to subviews or the superview will not pass the touch to its subviews in this case, so your button will not be receiving touches. Set your image view to have .userInteractionEnabled = YES and you should be fine.
I had the same problem and tried EVERYTHING. The thing that finally did it was implementing the method
(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
Just return whatever the height is of your custom cell (look in the NIB file)
Recently I've ran into such issue with legacy code. The reason was that earlier we used to add subviews to custom UITableViewCell instance itself and now we have to add to contentView of the cell instance.
I fixed it by changing:
addSubview(increaseButton)
to
contentView.addSubview(increaseButton)
Of course, isUserInteractionEnabled should be true.
Instead of button, you could try the same with an image. You could define which method to be called when the image is clicked.