I have a program that dynamically generates UIButtons in the center of
the screen with push of another button.
The buttons are not updating the x-coordinates when I rotate the device.
Here is my code for creating buttons:
- (IBAction)createButton:(UIButton *)sender {
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setBackgroundColor:[UIColor redColor]];
[button addTarget:self action:#selector(doSomething:) forControlEvents:UIControlEventTouchUpInside];
button.frame = CGRectMake(self.xCoord,self.yOffset,100.0,120.0);
[self.view addSubview:button];
_yOffset = _yOffset+130;
}
The XCoord and self.yOffset were set in viewDidLoad:
- (void)viewDidLoad {
[super viewDidLoad];
self.yOffset = 109;
self.xCoord = self.view.bounds.size.width/2-50;
}
The coordinates of the button in your code are fixed once they've been added to the view. If you want to update the frame of the buttons when the screen rotates, you'll need to trigger the repositioning of the buttons when the screen rotates.
AutoLayout in a storyboard makes this easier (if you just want a button to appear then you can add it in a storyboard and change its hidden property from NO to YES when the other button is pressed -- this won't be helpful if you want to add an arbitrary number of buttons, although you could have a hidden placeholder view that you use as a positioning reference)
If you want to keep the buttons x-position, you need to add Auto Layout constraints. There are a couple ways to do this programmatically. You can use the NSLayoutConstraint object directly or use Auto Layout's Visual Format Language. For more info, see Apple's documentation.
Related
I want to have several buttons and other objects in a long UIScrollView in my app. In storyboard, I added a UIScrollView to fill the entre view, and then created an IBOutlet in my .h file. I synthesized the scroller in my .m file, and then used the following code to start the scroller:
#synthesize scroller = _scroller;
- (void)viewDidLoad
{
[super viewDidLoad];
[_scroller setScrollEnabled:YES];
[_scroller setContentSize:CGSizeMake(640, 3000)];
}
So now I need to know how to actually add things, such as buttons, to the area of the scroller that extends below what you can see in the view. My problem is that as I add butons to my view in storyboard, I can only add things to what you can see in the view, and therefore need to know how to add buttons to part that I will scroll to!
Hopefully this is clear. Thanks for all your help!
UPDATE
I have posted a screencast that walks through this technique step-by-step.
ORIGINAL
The easiest way to handle this is simply to make the view in your storyboard taller. When the app runs, any of the normal container view controllers (UINavigationController, UITabBarController, UISplitViewController, or even UIViewController when it's the root view controller of its window) will resize the view to fit on the screen and scroll.
Here's an example of how to set it up in Xcode:
I changed the view controller's size from “Inferred” to “Freeform”. Then I changed its view's height from 460 to 800. (By the way, control-shift-click gives you a menu of all objects under the cursor.)
Here's what happens when I run it in the simulator:
As you can see, the view hierarchy was resized to fit the screen, but the subviews of the UIScrollView weren't repositioned, and the scroll view set its content size appropriately. (That may only work properly with autolayout, though...)
So, an example to you how to add a Button:
UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[btn setTitle:#"Cool title" forState:UIControlStateNormal];
[btn setFrame:CGRectMake(50, 700, 100, 100)];
[btn addTarget:self action:#selector(action:) forControlEvents:UIControlEventTouchUpInside];
[_scroller addSubview:btn];
You just need to set the frame of the view that you want to add and after that add it as a subview in your scroll.
You can you use the Size inspector(Left part of xcode) in order to position it. or reposition it programmatically.
Cheers,
Kel
I have(/had) a UITextField subclass which has a custom delete button as a rightView property.
This is working fine up until I rotate the device and then the button does not react anymore.
I changed my approach and 'cheated' a bit. Now I'm adding the UIButton on top of the UITextField in code. Which also works fine up until I rotate the device. I checked with backgroundColors if there are no other elements on top of the button.
I also tried removing the button and adding it again when the device rotates. It's visible but the action does not trigger. If I start my app in Portrait or in Landscape it works up until I rotate the device.
How I add the button:
if (!btn_delete)
{
btn_delete = [[UIButton alloc] initWithFrame:CGRectMake(self.view.frame.size.width - 70, (tf_search.frame.size.height / 2) - 8, 17, 16)];
[btn_delete setImage:[UIImage imageNamed:#"icon_cross_textfield"] forState:UIControlStateNormal];
[btn_delete addTarget:self action:#selector(clearTextField:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:btn_delete];
[self.view bringSubviewToFront:btn_delete];
}
else
{
[btn_delete removeFromSuperview];
btn_delete = nil;
}
Method -(void)clearTextField:(UIButton*)sender does not get called after rotation.
Any advice is appreciated.
The UIButton was added to a UIViewController's UIView which was part of a UIView of another UIViewController. They all had clearColour as backgroundColor so the UIButton was still visible but not in the bounds of the superView.
I want to have several buttons and other objects in a long UIScrollView in my app. In storyboard, I added a UIScrollView to fill the entre view, and then created an IBOutlet in my .h file. I synthesized the scroller in my .m file, and then used the following code to start the scroller:
#synthesize scroller = _scroller;
- (void)viewDidLoad
{
[super viewDidLoad];
[_scroller setScrollEnabled:YES];
[_scroller setContentSize:CGSizeMake(640, 3000)];
}
So now I need to know how to actually add things, such as buttons, to the area of the scroller that extends below what you can see in the view. My problem is that as I add butons to my view in storyboard, I can only add things to what you can see in the view, and therefore need to know how to add buttons to part that I will scroll to!
Hopefully this is clear. Thanks for all your help!
UPDATE
I have posted a screencast that walks through this technique step-by-step.
ORIGINAL
The easiest way to handle this is simply to make the view in your storyboard taller. When the app runs, any of the normal container view controllers (UINavigationController, UITabBarController, UISplitViewController, or even UIViewController when it's the root view controller of its window) will resize the view to fit on the screen and scroll.
Here's an example of how to set it up in Xcode:
I changed the view controller's size from “Inferred” to “Freeform”. Then I changed its view's height from 460 to 800. (By the way, control-shift-click gives you a menu of all objects under the cursor.)
Here's what happens when I run it in the simulator:
As you can see, the view hierarchy was resized to fit the screen, but the subviews of the UIScrollView weren't repositioned, and the scroll view set its content size appropriately. (That may only work properly with autolayout, though...)
So, an example to you how to add a Button:
UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[btn setTitle:#"Cool title" forState:UIControlStateNormal];
[btn setFrame:CGRectMake(50, 700, 100, 100)];
[btn addTarget:self action:#selector(action:) forControlEvents:UIControlEventTouchUpInside];
[_scroller addSubview:btn];
You just need to set the frame of the view that you want to add and after that add it as a subview in your scroll.
You can you use the Size inspector(Left part of xcode) in order to position it. or reposition it programmatically.
Cheers,
Kel
I want to have several buttons and other objects in a long UIScrollView in my app. In storyboard, I added a UIScrollView to fill the entre view, and then created an IBOutlet in my .h file. I synthesized the scroller in my .m file, and then used the following code to start the scroller:
#synthesize scroller = _scroller;
- (void)viewDidLoad
{
[super viewDidLoad];
[_scroller setScrollEnabled:YES];
[_scroller setContentSize:CGSizeMake(640, 3000)];
}
So now I need to know how to actually add things, such as buttons, to the area of the scroller that extends below what you can see in the view. My problem is that as I add butons to my view in storyboard, I can only add things to what you can see in the view, and therefore need to know how to add buttons to part that I will scroll to!
Hopefully this is clear. Thanks for all your help!
UPDATE
I have posted a screencast that walks through this technique step-by-step.
ORIGINAL
The easiest way to handle this is simply to make the view in your storyboard taller. When the app runs, any of the normal container view controllers (UINavigationController, UITabBarController, UISplitViewController, or even UIViewController when it's the root view controller of its window) will resize the view to fit on the screen and scroll.
Here's an example of how to set it up in Xcode:
I changed the view controller's size from “Inferred” to “Freeform”. Then I changed its view's height from 460 to 800. (By the way, control-shift-click gives you a menu of all objects under the cursor.)
Here's what happens when I run it in the simulator:
As you can see, the view hierarchy was resized to fit the screen, but the subviews of the UIScrollView weren't repositioned, and the scroll view set its content size appropriately. (That may only work properly with autolayout, though...)
So, an example to you how to add a Button:
UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[btn setTitle:#"Cool title" forState:UIControlStateNormal];
[btn setFrame:CGRectMake(50, 700, 100, 100)];
[btn addTarget:self action:#selector(action:) forControlEvents:UIControlEventTouchUpInside];
[_scroller addSubview:btn];
You just need to set the frame of the view that you want to add and after that add it as a subview in your scroll.
You can you use the Size inspector(Left part of xcode) in order to position it. or reposition it programmatically.
Cheers,
Kel
I want to add a view and a button programmatically like follows.
The problem is that the button does not react on clicking. I mean neither does it get highlighted or calls the selector.
The reason is that I want to implement a list row for a recording (a sound file). The list row should be selectable for drill-down and have a play button. So I got a RecordingView subclassing UIView that itself adds the button using a target from the constructor. See code below.
If anyone has a better approach to do this that could also be a solution.
#implementation MyViewController
- (IBAction) myAction {
RecordingView *recordingView = [[RecordingView alloc] initWithFrame:CGRectMake(30, 400, 130, 50)withTarget:self];
[recordingView setUserInteractionEnabled:YES];
[[self view] addSubview:recordingView];
}
#implementation RecordingView
- (id)initWithFrame:(CGRect)frame withTarget:(id) target
{
self = [super initWithFrame:frame];
UIButton *playButton = [[UIButton alloc] initWithFrame:CGRectMake(185, 5, 80, 40)];
[playButton setTitle:#"Play" forState:UIControlStateNormal];
[playButton setTitleColor:[UIColor darkTextColor]forState:UIControlStateNormal];
// creating images here ...
[playButton setBackgroundImage:imGray forState: UIControlStateNormal];
[playButton setBackgroundImage:imRed forState: UIControlStateHighlighted];
[playButton setEnabled:YES];
[playButton setUserInteractionEnabled:YES];
[playButton addTarget: target
action: #selector(buttonClicked:)
forControlEvents: UIControlEventTouchDown];
[self addSubview:playButton];
return self;
}
When I add the button the same way, directly in the view controller .m-file, the button does react on clicking. So there is something about the RecordingView. What do I need to do different here?
Also, are there any better ways to provide the target and selector for the touch event?
You may simply need to set userInteractionEnabled to YES on your RecordingView.
Another problem is that you are creating the RecordingView with a frame width of 130, but you are setting the X-axis origin of playButton to 185. This means playButton is entirely outside of the bounds of its superview. The default value for clipsToBounds is NO, so the button is drawn anyway. But touch events will never reach the button, because they are rejected when the system hit-tests the RecordingView.
This is from the hitTest:withEvent: documentation in UIView Class Reference:
Points that lie outside the receiver’s bounds are never reported as hits, even if they actually lie within one of the receiver’s subviews. This can occur if the current view’s clipsToBounds property is set to NO and the affected subview extends beyond the view’s bounds.
You need to either make RecordingView's frame wider, or move playButton to be inside the bounds of its superview.