Displaying UIButton programmatically - ios

I'm trying to display a button to the view programmatically with this code:
- (void)viewDidLoad {
_detailButton = [UIButton buttonWithType:UIButtonTypeCustom];
_detailButton.frame = CGRectMake(23, 294, 72, 37);
[_detailButton setTitle:#"UIButton!" forState:UIControlStateNormal];
[_detailButton addTarget:self
action:#selector(showPop:)
forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:_detailButton];
}
I have the button declared in the .h file like this:
#property (strong, nonatomic) UIButton *detailButton;
The code does not throw any errors or warnings, but when I run there is no button displayed.

I check your code in my project its working fine i think in your case there are some other view that cover this button so check that your code has no problem at all.

Your button probably covered by another view. Just make sure its on top of other views.
In viewWillAppear add the following line of code:
[self.view bringSubviewToFront:self.detailButton];

If your button's type is of UIButtonTypeCustom, the button's default title color is white, so you can't see it if your view's background color is white.
[_detailButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];

Related

Custom UIButton No Longer Works After Changing UIView to UIViewController

This code worked in a UIView container, but after changing that container to a UIViewController, the code no longer works:
-(void)viewDidLoad
{
[super viewDidLoad];
[self.view setUserInteractionEnabled:YES];
// set button
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
button.frame = CGRectMake(60, 30, 220, 220);
[button setImage:self.obj.img forState:UIControlStateNormal];
[button addTarget:self action:#selector(selected:) forControlEvents:UIControlEventTouchUpInside];
[button setUserInteractionEnabled:YES];
[self.view addSubview:button];
}
-(void) selected:(UIButton *) button // also tried (id) sender
{
NSLog(#“Button Selected“);
}
These containers are created programmatically (dynamically), from web services, so I cannot use Storyboard. The reason for changing to a UIViewController is that I need a segue to another screen. Also, these containers are placed in a UIScrollView.
Everything else is working properly, except the selector.
Setting the userInteraction wasn't necessary earlier, but I've gone ahead and tried that in different configurations. I've added this to the scrollview, the viewController, and the button, just for good measure.
I even tried some online tutorials for programmatically creating UIButtons in UIViewControllers and was able to do that just fine. Not sure what the issue is here. Thanks.

Having a UIButton be tapped in a UICollectionViewCell

I have a UICollectionView with its cells all laid out.
I have this declared as a subview:
#property (nonatomic, strong) UIButton *aButton;
I then have that declared in each cell like so:
if (_aButton == nil)
{
_aButton = [UIButton buttonWithType:UIButtonTypeSystem];
}
// Add in all _aButton info here
[self.contentView addSubview:_aButton];
// Call to button pressed for button
[_aButton addTarget:self action:#selector(aButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
The button click method is like so:
- (IBAction) aButtonPressed:(UIButton *) sender
{
// Code never gets heree
}
The if(_aButton== `nil) is needed since cells get reused.
How do I make this work now? Thanks.
Add button action code before button added to view.... May be it will work .
// Call to button pressed for button
[_aButton addTarget:self action:#selector(aButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
// Add in all _aButton info here
[self.contentView addSubview:_aButton];
I think, the way you are initializing the button is going to give you frame as 0,0,0,0 . So first give it a proper frame and title to be visible on the screen.
Then try tapping on that title and see if it works or not.
It's unclear what you trying to achieve here, but the button is not working because you not setting it's position and size on the cell. It could be done by setting frame or layout constraints.
Try to set button frame:
_aButton.frame = CGRectMake(0.0f, 0.0f, 50.0f, 50.0f);
You can also set background color for the button, just to make it visible on the cell:
_aButton.backgroundColor = [UIColor redColor];
Everything else is correct, button should work.

Changing a UIButton's image when it's tapped

I have a UIButton that I am programmatically creating and adding to a UITableViewCell.
I have successfully set it up so that if you tap the button and keep holding it down, it will change to the image that I have set for the "highlighted state", but this is not good enough.
When the user taps the button, I need it to completely change to the new image. If the user taps the button again, I want it to change back to the original image.
I want the image to change every time they tap. Right now it changes if they tap and keep holding it down, but it switches back to the original image as soon as they are done holding it down.
Here is the code that I have so far for my buttons:
UIImage *addFriendButtonImage = [UIImage imageNamed:#"SliderThumb-Normal-G"];
UIImage *addFriendButtonImageHighlighted = [UIImage imageNamed:#"SliderThumb-Normal"];
UIButton *addFriendButton = [[UIButton alloc]init];
addFriendButton.frame = CGRectMake(237, -10, 64, 64);
[addFriendButton setImage:addFriendButtonImage forState:UIControlStateNormal];
[addFriendButton setImage:addFriendButtonImageHighlighted forState:UIControlStateHighlighted];
I also tried setting the state for the new image to "UIControlStateSelected" but all that does it make the original image a little darker. It doesn't even change to the new image, and once again it only shows it's effect if you are holding the button down.
Set the image for both the UIControlStateHighlighted and UIControlStateSelected states:
[addFriendButton setImage:addFriendButtonImage forState:UIControlStateNormal];
[addFriendButton setImage:addFriendButtonImageHighlighted forState:UIControlStateHighlighted];
[addFriendButton setImage:addFriendButtonImageHighlighted forState:UIControlStateSelected];
Then listen for UIControlEventTouchUpInside:
[addFriendButton addTarget:self action:#selector(handleTouchUpInside:) forControlEvents:UIControlEventTouchUpInside];
Then update the selected state:
- (void)handleTouchUpInside:(UIButton *)sender {
sender.selected = !sender.selected;
}
What you want is to set new image with [addFriendButton setImage:someImage forState:UIControlStateNormal]; every time the user taps on addFriendButton (look for event UIControlEventTouchUpInside).
If you want you can still assign appropriate highlight image on [addFriendButton setImage:someImage_highlighted forState:UIControlStateHighlighted];
You need to create an IBAction method for your button. If you are using a storyboard to design your view controllers go to the respective view controller in the assistant editor (tap on the icon in the upper right corner of the Xcode window), CTRL+drag the a line from the button to the .h file of your view controller's class like this:
Select Action and enter a named for the method like touchUpInsideButton.
Repeat the same steps to create a property for your button. (But select Outlet instead of Action and give your button a name like myButton.) Now you should have these two lines in your .h file:
#property (strong, nonatomic) IBOutlet UIButton *myButton;
- (IBAction)touchUpInsideButton:(id)sender;
Now go to the .m file of your view controller. Search for the newly created action method - (IBAction)touchUpInsideButton:(id)sender and enter the following code to change the button's image when the user taps the button:
- (IBAction)touchUpInsideButton:(id)sender {
UIImage *myImage = [UIImage imageNamed:#"myImageName"];
[self.myButton setImage:myImage forState:UIControlStateNormal];
}
(You can put any code inside this method that is executed whenever the user taps the button.)
I would recommend this method if you are using a storyboard. If not please refer to #Corey's reply.

UIView addSubview works once but not twice

I would like to add a UIButton in a UIView from my xib file.
In my xib, I declare a UIView outlet named "content" with interface builder: here is the generated code :
#property (weak, nonatomic) IBOutlet UIView *content;
I would like to add a button, here is the code for this:
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setTitle:#"Show View" forState:UIControlStateNormal];
button.frame = CGRectMake(0, 8, 141.0, 56.0);
[button setBackgroundImage:[UIImage imageNamed:#"TAB_NORMAL"]
forState:UIControlStateNormal];
button.frame = CGRectMake(0, 8, 56.0, 141.0);
[self.content addSubview:button];
If I put this code in -viewDidLoad method, it works, but if I put it in a function called later, the button is never displayed.
What could be the reason ?
Thanks for your help.
If your UIView content is a top level item, that is, not contained in your main view - then it has to be strong. Only items that are not top-level can use weak, since the containing view would keep a strong reference to them. I also assume that content was immediately added to the primary view, which kept a strong reference to it (it in viewDidLoad happened before ARC nil'ed out content.
If for some reason changing the property to strong does not fix the problem, then for sure add a NSLog (or assert) to insure that content is non-nil.

UIView/UIButton coordinates flipped

I have a coreplot project. The class of the view in viewcontroller has been changed to CPTGraphHostingView.
After creating the graph (this works fine),
I am adding a button as a subview , this launches a popover
the button shown is inverted. I have the same control in different view controllers and it works fine. The Popover also appears fine.
Here is the code that creates and adds the UIButton
UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[button addTarget:self
action:#selector(monthSelection)
forControlEvents:UIControlEventTouchDown];
[button setTitle:#"Change Month" forState:UIControlStateNormal];
button.frame = CGRectMake(330, 650, 111, 40);
[self.view addSubview:button];
[here is a screenshot of whats happening. UIButton is suppose to show somewhere below the popover. What am i missing.
Do not add subviews to the graph hosting view. Instead, make other views siblings of the hosting view, i.e., add them as subviews of the same superview.

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