I have several UIView layers in one ViewController.
How can I determine the order of UIView programmatically?
I found the solution...
In the UIView documentation, where are several methods listed for the manipulation of the order of subviews:
bringSubviewToFront(_:)
sendSubviewToBack(_:)
removeFromSuperview()
insertSubview(_:atIndex:)
insertSubview(_:aboveSubview:)
insertSubview(_:belowSubview:)
exchangeSubviewAtIndex(_:withSubviewAtIndex:)
In Swift 4.0
view.sendSubview(toBack:yourUIView)
view.bringSubview(toFront:yourUIView)
Views are ordered from back-most to front-most in view.subviews array.
For example, here are 3 subview added to an empty view.
view.addSubview(UILabel())
view.addSubview(UIButton())
view.addSubview(UITextField())
Printing the subviews with the following code
for view in view.subviews {
print(view.debugDescription)
}
has the output
<UILabel: 0x7feef00042e0; frame = (0 0; 0 0); userInteractionEnabled = NO; layer = <_UILabelLayer: 0x60400008c210>>
<UIButton: 0x7feef00045c0; frame = (0 0; 0 0); opaque = NO; layer = <CALayer: 0x604000222300>>
<UITextField: 0x7feeef02c800; frame = (0 0; 0 0); text = ''; opaque = NO; gestureRecognizers = <NSArray: 0x60800005b090>; layer = <CALayer: 0x604000222280>>
When the views are reordered, the position in view.subviews changes
if let button = view.subviews.first(where: { $0 is UIButton }) {
view.bringSubview(toFront: button)
}
Now, printing the view, has the output
<UILabel: 0x7feef00042e0; frame = (0 0; 0 0); userInteractionEnabled = NO; layer = <_UILabelLayer: 0x60400008c210>>
<UITextField: 0x7feeef02c800; frame = (0 0; 0 0); text = ''; opaque = NO; gestureRecognizers = <NSArray: 0x60800005b090>; layer = <CALayer: 0x604000222280>>
<UIButton: 0x7feef00045c0; frame = (0 0; 0 0); opaque = NO; layer = <CALayer: 0x604000222300>>
Related
I am trying to loop all my subviews and print them in NSLog.
I have developed this recursive method:
- (void)allSubViews:(UIView*)mainV
{
for (UIView *view in mainV.subviews) {
NSLog(#"%#", view);
if ([[view subviews]count]>0) {
[self allSubViews:view];
}
}
}
which I call from MainViewController.m:
[self allSubViews:self.myView];
The result is:
2015-09-12 11:18:48.919 Profile-Statistics[3153:506562] <_UILayoutGuide: 0x7fc70bf1c330; frame = (0 0; 0 0); hidden = YES;
layer = >
2015-09-12 11:18:48.919 Profile-Statistics[3153:506562] <_UILayoutGuide: 0x7fc70bf1ced0; frame = (0 0; 0 0); hidden = YES;
layer = >
My View has Top and Bottom Layout Guide and a View which has 3 UIButtons, 1 ImageView and 1 UIView.
Did I miss something here?
Update:
Screenshot of StoryBoard
For what it's worth, I tried this in a sample project with a bunch of subviews and it worked as expected.
#import "ViewController.h"
#interface ViewController ()
#end
#implementation ViewController
- (IBAction)printButtonTapped:(id)sender {
[self allSubviews:self.view];
}
- (void) allSubviews:(UIView*) parent {
NSLog(#"%#", parent);
for (UIView *child in parent.subviews) {
[self allSubviews:child];
}
}
#end
Console output is:
2015-09-13 22:06:00.904 RecursivePrint[66243:3455899] <UIView: 0x7fa902e0e6e0; frame = (0 0; 375 667); autoresize = W+H; layer = <CALayer: 0x7fa902e15030>>
2015-09-13 22:06:00.905 RecursivePrint[66243:3455899] <UIView: 0x7fa902e0e840; frame = (70 56; 452 337); autoresize = RM+BM; layer = <CALayer: 0x7fa902e15050>>
2015-09-13 22:06:00.905 RecursivePrint[66243:3455899] <UIView: 0x7fa902e24c90; frame = (31 33; 153 160); autoresize = RM+BM; layer = <CALayer: 0x7fa902e21f00>>
2015-09-13 22:06:00.906 RecursivePrint[66243:3455899] <UIView: 0x7fa902e24fc0; frame = (219 41; 153 160); autoresize = RM+BM; layer = <CALayer: 0x7fa902e1ec10>>
2015-09-13 22:06:00.906 RecursivePrint[66243:3455899] <UIButton: 0x7fa902d177e0; frame = (164.5 603; 46 30); opaque = NO; autoresize = RM+BM; layer = <CALayer: 0x7fa902d16c80>>
2015-09-13 22:06:00.907 RecursivePrint[66243:3455899] <UIButtonLabel: 0x7fa902d1f010; frame = (0 6; 46 18); text = 'Button'; alpha = 0.2; opaque = NO; userInteractionEnabled = NO; layer = <_UILabelLayer: 0x7fa902d1f670>>
2015-09-13 22:06:00.907 RecursivePrint[66243:3455899] <_UILayoutGuide: 0x7fa902e25ed0; frame = (0 0; 0 20); hidden = YES; layer = <CALayer: 0x7fa902e21b20>>
2015-09-13 22:06:00.907 RecursivePrint[66243:3455899] <_UILayoutGuide: 0x7fa902f77ec0; frame = (0 667; 0 0); hidden = YES; layer = <CALayer: 0x7fa902f09f70>>
As a side note, this is the first time in over a year that I've tried to do something in Objective-C. The Swift version seems so much easier to understand:
import UIKit
class ViewController: UIViewController {
#IBAction func printButtonTapped(sender: UIButton) {
printSubviews(self.view)
}
}
func printSubviews(parent:UIView) {
print(parent)
for child in parent.subviews {
printSubviews(child)
}
}
In addition, the Swift version of printSubviews is defined as a function, not a method so you don't call it from self, you just call it with the top level view you want to start with.
I have a ViewController and some label and textfield for user to input, and in some point I need to loop over all textfield to collect the user's input.
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
self.configureView()
for views in self.view.subviews {
if view is UITextField
{
println("inside")
}
println(views.description)
}
}
For this code, the "inside" never print out. But I do see some the information of views.description
<UILabel: 0x7fa4b1c7bd00; frame = (16 97; 76 21); text = 'FromDate'; opaque = NO; autoresize = RM+BM; userInteractionEnabled = NO; layer = <_UILabelLayer: 0x7fa4b1c44580>>
<UILabel: 0x7fa4b1c9fd60; frame = (16 169; 82 21); text = 'ControlNO'; opaque = NO; autoresize = RM+BM; userInteractionEnabled = NO; layer = <_UILabelLayer: 0x7fa4b1c77fb0>>
>
<UITextField: 0x7fa4b1c7a050; frame = (106 95; 197 30); text = ''; clipsToBounds = YES; opaque = NO; autoresize = RM+BM; layer = <CALayer: 0x7fa4b1c6c800>>
<UITextField: 0x7fa4b1c9c060; frame = (106 126; 197 30); text = ''; clipsToBounds = YES; opaque = NO; autoresize = RM+BM; tag = 1; layer = <CALayer: 0x7fa4b1c9c2c0>>
<_UILayoutGuide: 0x7fa4b1d11d20; frame = (0 0; 0 0); hidden = YES; layer = <CALayer: 0x7fa4b1d11e00>>
<_UILayoutGuide: 0x7fa4b1d253f0; frame = (0 0; 0 0); hidden = YES; layer = <CALayer: 0x7fa4b1d12f60>>
but if I println(views.dynamicType) I could only see ExistentialMetatype.
What is wrong in my code?
The loop variable is called views, but you test view (which is
not the loop variable and therefore identical to self.view):
for views in self.view.subviews { // "views" here
if view is UITextField { // "view" here
println("inside")
}
}
If you rename the loop variable to view
for view in self.view.subviews {
if view is UITextField {
println("inside")
}
}
then everything works as expected.
You can use isKindOfClass:
var tex = UITextField()
if tex.isKindOfClass(UITextField){
println("yes")
}
#Christian's code will work. Here is another solution.
if let view = tex as? UITextField {
// view is a UITextField
}
I am working on one app. Which capture images continuously, there is one button to stop capturing. But the problem is that button targeted method is not being called. Even when I clicked on the screen anywhere it didn't detect touch or gesture. I have implemented gesture and touch delegate methods to check. Capturing image is not on main thread so main thread is free. So I am not able to find the reason why view not able to detect the touch. There are almost 6-7 button on that particular view, none of them trigger their method. While working with ios7 its running properly, It will detect touch and button targeted method trigger also.
I have thought that there should be any-view that will be overlap those button so i print the stake of subview , which is as below.Button which stop capturing is with text "START". I have just share stake after START button only as i think in stake the last item will be on top in view.
<UIButtonLabel: 0x15dfb0d0; frame = (5 14; 41 16); text = 'START';
opaque = NO; userInteractionEnabled = NO; layer = <_UILabelLayer:
0x15dfb190>>
<UIButton: 0x15e8c590; frame = (63 7; 36 32); opaque = NO; autoresize
= RM+BM; layer = <CALayer: 0x15e8c690>>
<UIButtonLabel: 0x15df0400; frame = (15 10; 6 12); text = '0'; opaque
= NO; userInteractionEnabled = NO; layer = <_UILabelLayer: 0x15d98db0>>
<UIImageView: 0x15e97c00; frame = (-295 -272; 1557 1568);
clipsToBounds = YES; hidden = YES; autoresize = W+H;
autoresizesSubviews = NO; layer = <CALayer: 0x15ea2920>>
<_UILayoutGuide: 0x15e90ba0; frame = (0 0; 0 0); hidden = YES; layer =
<CALayer: 0x15ea2b10>>
<_UILayoutGuide: 0x15e86120; frame = (0 1024; 0 0); hidden = YES;
layer = <CALayer: 0x15e6fc40>>
<MPVolumeView: 0x15db7840; frame = (18 340; 284 23); alpha = 0; opaque
= NO; layer = <CALayer: 0x15dbd2e0>>
<UILabel: 0x15daee40; frame = (0 0; 0 0); text = 'No Volume
Available'; opaque = NO; autoresize = W+BM; userInteractionEnabled =
NO; layer = <_UILabelLayer: 0x15dd5be0>>
<MPButton: 0x15dd5e00; baseClass = UIButton; frame = (131.5 2.5; 21.5
18); alpha = 0; opaque = NO; autoresize = LM+BM; layer = <CALayer:
0x15dd6030>>
<UIImageView: 0x15de0c30; frame = (-39.25 -41; 100 100); alpha = 0;
opaque = NO; userInteractionEnabled = NO; tag = 1886548836; layer =
<CALayer: 0x15ea5330>>
<UIImageView: 0x15ea5790; frame = (0 0; 21.5 18); clipsToBounds = YES;
opaque = NO; userInteractionEnabled = NO; layer = <CALayer:
0x15ea5810>>
I am using auto-layout. Please can you help me to handle this problem. I am new with auto-layout. so anything that i can change in storyboard get this problem solved please let me know. Thanks in advance.
Thanks for all your answers. I got solution by moving irate code from +initialize method of AppDelegate to didFinishLaunchingWithOptions method. My iRate get initialized and configure but don't show popup. May be that's why i was not able to perform any touch on screen.
When is UIView.didAddSubview called ?
I have created a simple View and ViewController app.
When I run this app, didAddSubview is called twice on first time the View appears.
https://github.com/toshi0383/HelloUIView
below is the log output
didAddSubView
<_UILayoutGuide: 0x7f92d3425210; frame = (0 0; 0 0); hidden = YES; layer = <CALayer: 0x7f92d3419cf0>>
didAddSubView
<_UILayoutGuide: 0x7f92d3425c10; frame = (0 0; 0 0); hidden = YES; layer = <CALayer: 0x7f92d34244a0>>
viewDidLoad
[<_UILayoutGuide: 0x7f92d3425210; frame = (0 0; 0 0); hidden = YES; layer = <CALayer: 0x7f92d3419cf0>>, <_UILayoutGuide: 0x7f92d3425c10; frame = (0 0; 0 0); hidden = YES; layer = <CALayer: 0x7f92d34244a0>>]
didMoveToWindow
didMoveToSuperView
layoutSubviews
<ViewTest.View: 0x7f92d3424bc0; frame = (0 0; 375 667); autoresize = W+H; layer = <CALayer: 0x7f92d3423320>>
UILayoutGuide is a private Apple class.
UILayoutGuide is normally referred to -topLayoutGuide and -bottonLayoutGuide, those are not really constraints.
same questions here:
stack overflow : what-is-uilayoutguide
I'm getting some issues with a constraint relative from the bottom layout.
There are some views inside a UITabBarViewController. When I change to another view from the tab and return to first one, the viewcontroller not recognize the bottom layout as the tab bar, but from the bottom of the view.
I uploaded the problem here: https://sites.google.com/site/rveducationapps/layoutError.png?attredirects=0&d=1
I already tried put in ViewDidAppear and also ViewWillAppear:
[self.view layoutSubviews];
[self.view setNeedsUpdateConstraints];
I logged the subviews in the two cases, the right one and after I exit and return to the view:
subviews:(
"<UIView: 0x146b2260; frame = (210 0; 814 712); autoresize = RM+BM; layer = <CALayer: 0x146b22c0>>",
"<UIButton: 0x146a9eb0; frame = (727 672; 287 30); opaque = NO; autoresize = RM+BM; layer = <CALayer: 0x146aa070>>",
"<UITableView: 0x151d3400; frame = (0 0; 210 761); clipsToBounds = YES; autoresize = W+H; gestureRecognizers = <NSArray: 0x146b14b0>; layer = <CALayer: 0x146ade20>; contentOffset: {0, 0}>",
"<_UILayoutGuide: 0x146b23b0; frame = (0 0; 0 20); hidden = YES; layer = <CALayer: 0x146b24a0>>",
"<_UILayoutGuide: 0x146b28a0; frame = (0 712; 0 56); hidden = YES; layer = <CALayer: 0x146b2910>>"
)
subviews:(
"<UIView: 0x146b2260; frame = (210 0; 814 768); autoresize = RM+BM; layer = <CALayer: 0x146b22c0>>",
"<UIButton: 0x146a9eb0; frame = (727 728; 287 30); opaque = NO; autoresize = RM+BM; layer = <CALayer: 0x146aa070>>",
"<UITableView: 0x151d3400; frame = (0 0; 210 817); clipsToBounds = YES; autoresize = W+H; gestureRecognizers = <NSArray: 0x146b14b0>; layer = <CALayer: 0x146ade20>; contentOffset: {0, 0}>",
"<_UILayoutGuide: 0x146b23b0; frame = (0 0; 0 20); hidden = YES; layer = <CALayer: 0x146b24a0>>",
"<_UILayoutGuide: 0x146b28a0; frame = (0 768; 0 0); hidden = YES; layer = <CALayer: 0x146b2910>>"
)
I see there are some differences, specially in:"<_UILayoutGuide: 0x146b28a0; frame = (0 712; 0 56); hidden = YES; layer = <CALayer: 0x146b2910>>"
But I don't know how to fix it.
EDITED:
I think I fixed. I selected the UIViewController in the Storyboard and disabled the EXTEND EDGES->Under Bottom Bars option.
If you are transitioning from your UITabBarViewController to a new UIViewController, and then attempting to go back to your tabBarController from that UIViewController, then you could simply segue back to the UITabBarViewController(The segue will take you back to your rootViewController for your UITabBarViewController).
If you need to transition back to a specific tab, instantiate a custom segue and send it back to a different tab using a different specified VC, this can be set in your UITabBarViewController class or in your applications AppDelegate.m file.