I'm using UINavigationController and I have a UIView added to self.window
UIView *myView = [[UIView alloc] init];
myView.frame=CGRectMake(0,20,320,100);//20 is to position view under status bar
[[[self.window subviews] objectAtIndex:0] addSubview:myView];
This is done in AppDelegate.m file.
And this way myView covers up the navigation bar completely.
However, when the screen orientation changes, somehow the navigation bar is brought to the very front (just like what bringSubViewToFront does) and is on top of myView (a portion of view is covered up by navigation bar).
Does anyone know why this happened? Is there a way I can keep myView on top of everything?
If you don't want to show the navigation bar, just hide it:
self.navigationController.navigationBarHidden = YES;
or:
[self.navigationController setNavigationBarHidden:YES animated:YES];
if you want to animate the change from not hidden to hidden.
You can also adjust the "z" coordinate for stuff on the screen
[aview sendSubviewToBack:asubview];
and
[aview sendSubviewToFront:asubview];
When I receive a memory warning in my navigation based iPhone App the background image disappears in the previously allocated navigation controllers.
The background image is set as the background property of a UIView. This view is then added to the main window of the App delegate:
UIView *backgroundView = [[UIView alloc] initWithFrame: window.frame];
backgroundView.backgroundColor = [UIColor colorWithPatternImage:[[Utilities sharedManager] getImageWithName:#"Hintergrund2"]];
backgroundView.tag = 56789;
[window addSubview:backgroundView];
[backgroundView release];
[window addSubview:[navigationController view]];
[window makeKeyAndVisible];
After I received the memory warning message and pressed the back button of the navigation controller the previous navigation controller shows up the normal Apple gray background. I have to navigate back to my home screen and navigate forward to "reset" the background image.
Can anyone tell me why the background disappears? It is not because of the image, when I set the background to a standard UIColor like blackColor the background (color) also disappears.
Thank you in advance for your help!
regards
Phil
It is undefined what the OS does with stuff added directly to the main UIWindow in case of low memory situations.
Maybe consider using a simple UIViewController for the background? You will then at least get callbacks when there is a low memory situation.
First, you should probably add your controller to the window like this:
window.rootViewController = navigationController;
I haven't tested this, but perhaps you can set the background color of the window directly:
window.backgroundColor = [UIColor colorWithPatternImage:[[Utilities sharedManager] getImageWithName:#"Hintergrund2"]];
If that doesn't work, you'll need a better way to recreate your view state in low memory situations. The most standard way to do this is by defining the background in each xib, which is reloaded. Alternatively, you could catch the low memory warning and recreate as needed by seeing if your backgroundView has a superview.
Make sure that you are setting the calling self.view.backgroundColor = [UIColor clearColor]; in the view controller's - (void) viewDidLoad otherwise the window's image will not be displayed.
- (void) viewDidLoad
{
[super viewDidLoad];
self.view.backgroundColor = [UIColor clearColor];
...
}
My problem was that I set the view's backgroundColor when it is initialized
MyTableViewController *myTVC =
[[MyTableViewController alloc] initWithStyle:UITableViewStyleGrouped];
myTVC.view.backgroundColor = [UIColor clearColor];
and not in - (void) viewDidLoad.
In this situation, the UITableViewController's view's background color was set after it was initially created. However after a low memory warning, the UIViewController's that were not displayed have - (void) viewDidUnload called on them. That deallocate their views. Just before the UIViewController was to be displayed again, - (void) viewDidLoad was called and created a new view, but the view's background color was set to the default which is not clear.
I currently have several view controllers and transitions set up throughout my app using:
ViewController2 *controller2 = [[ViewController2 alloc] initWithNibName:#"ViewController2" bundle:nil];
controller2.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
[self presentModalViewController:controller2 animated:YES];
[controller2 release]; controller2 = nil;
What I really want is when the vertical transition is made, I want an image of bubbles to travel up the screen with the transition. Is there anyway of adding an Image to these transitions. If not I would like to know how to create this effect as I have seen it in apps before.
Thanks in Advance,
Adam
Simple way would be to add a UIImageView the size of the view being animated, with your bubbles image set to it as a subview of that view. You can then remove it in the viewDidUnload or where appropriate in your code.
All of my view has a blue navigation bar but when I want user to choose a photo, the UIImagePicker is black. I tried to set the navigation bar of UIImagePickerController to blue using UIBarStyleDefault but it does not work for me, the color is still black. I tried with other UIBarStyle like UIBarStyleBlack and UIBarStyleOpaque as well but it doesn't change the navigation bar of the picker anyway. Here is my code
// Let the user choose a new photo.
UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];
imagePicker.delegate = self;
imagePicker.navigationBar.barStyle = UIBarStyleDefault;
[self presentModalViewController:imagePicker animated:YES];
[imagePicker release];
Another way is using
- (void)navigationController:(UINavigationController *)navigationController
willShowViewController:(UIViewController *)viewController
animated:(BOOL)animated {
navigationController.navigationBar.barStyle = UIBarStyleDefault;
}
that is an istance method of the UINavigationControllerDelegate protocol.
This will change the navigation bar style to blue.
I think there is no way to change it. So my solution is using Color Meter to get the color of the default navigation bar in color code: red code, blue code, green code. Then I use the method
imagePicker.navigationBar.tintColor = [UIColor colorWithRed:redCode green:greenCode blue:blueCode alpha:0.1];
UINavigationBar tintColor
UIColor Reference
using the delegate to change it worked for me.
I'm trying to create a transparent modal View on top of my navigation controller. Does anyone know if this is possible?
A modal view will cover the view it is pushed on top of as well as the navigation bar for your navigation controller. However, if you use the -presentModalViewController:animated: approach, then once the animation finishes the view just covered will actually disappear, which makes any transparency of your modal view pointless. (You can verify this by implementing the -viewWillDisappear: and -viewDidDisappear: methods in your root view controller).
You can add the modal view directly to the view hierarchy like so:
UIView *modalView =
[[[UIView alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
modalView.opaque = NO;
modalView.backgroundColor =
[[UIColor blackColor] colorWithAlphaComponent:0.5f];
UILabel *label = [[[UILabel alloc] init] autorelease];
label.text = #"Modal View";
label.textColor = [UIColor whiteColor];
label.backgroundColor = [UIColor clearColor];
label.opaque = NO;
[label sizeToFit];
[label setCenter:CGPointMake(modalView.frame.size.width / 2,
modalView.frame.size.height / 2)];
[modalView addSubview:label];
[self.view addSubview:modalView];
Adding the modalView as a subview to the root view like this will not actually cover the navigation bar, but it will cover the entire view below it. I tried playing around with the origin of the frame used to init the modalView, but negative values cause it to not display. The best method that I found to cover the entire screen besides the status bar is to add the modalView as a subview of the window itself:
TransparentModalViewAppDelegate *delegate = (TransparentModalViewAppDelegate *)[UIApplication sharedApplication].delegate;
[delegate.window addSubview:modalView];
The easiest way is to use modalPresentationStyle property of navigationController (but you'll have to make animation by yourself):
self.navigationController.modalPresentationStyle = UIModalPresentationCurrentContext;
[self presentModalViewController:modalViewController animated:NO];
modalViewController.view.alpha = 0;
[UIView animateWithDuration:0.5 animations:^{
modalViewController.view.alpha = 1;
}];
I accomplish this most easily by setting up an "OverlayViewController" that sits above all other subviews of my window or root view. Set this up in your app delegate or root view controller, and make OverlayViewController a singleton so that it can be accessed from anywhere in your code or view controller hierarchy. You can then call methods to show modal views, show activity indicators, etc, whenever you need to, and they can potentially cover any tab bars or navigation controllers.
Sample code for root view controller:
- (void)viewDidLoad {
OverlayViewController *o = [OverlayViewController sharedOverlayViewController];
[self.view addSubview:o.view];
}
Sample code you might use to display your modal view:
[[OverlayViewController sharedOverlayViewController] presentModalViewController:myModalViewController animated:YES];
I haven't actually used -presentModalViewController:animated: with my OverlayViewController but I expect this would work just fine.
See also: What does your Objective-C singleton look like?
I had this same problem and in order to The solution is to add the modal view with addSubview: and animate the change in the view hierarchy with UIView’s animateWithDuration:delay:options:animations:completion:
I added a property and 2 methods to a subclass of UIViewController (FRRViewController) that includes other functionalities. I will be publishing the whole stuff on gitHub soon, but until then you can see the relevant code below. For more info, you can check my blog: How to display a transparent modal view controller.
#pragma mark - Transparent Modal View
-(void) presentTransparentModalViewController: (UIViewController *) aViewController
animated: (BOOL) isAnimated
withAlpha: (CGFloat) anAlpha{
self.transparentModalViewController = aViewController;
UIView *view = aViewController.view;
view.opaque = NO;
view.alpha = anAlpha;
[view.subviews enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
UIView *each = obj;
each.opaque = NO;
each.alpha = anAlpha;
}];
if (isAnimated) {
//Animated
CGRect mainrect = [[UIScreen mainScreen] bounds];
CGRect newRect = CGRectMake(0, mainrect.size.height, mainrect.size.width, mainrect.size.height);
[self.view addSubview:view];
view.frame = newRect;
[UIView animateWithDuration:0.8
animations:^{
view.frame = mainrect;
} completion:^(BOOL finished) {
//nop
}];
}else{
view.frame = [[UIScreen mainScreen] bounds];
[self.view addSubview:view];
}
}
-(void) dismissTransparentModalViewControllerAnimated:(BOOL) animated{
if (animated) {
CGRect mainrect = [[UIScreen mainScreen] bounds];
CGRect newRect = CGRectMake(0, mainrect.size.height, mainrect.size.width, mainrect.size.height);
[UIView animateWithDuration:0.8
animations:^{
self.transparentModalViewController.view.frame = newRect;
} completion:^(BOOL finished) {
[self.transparentModalViewController.view removeFromSuperview];
self.transparentModalViewController = nil;
}];
}
}
Here's what I did to solve the problem - Google the details but this approach worked very well for me:
Take a screenshot of the underlying view. https://devforums.apple.com/message/266836 - this leads to a ready-made method that returns a UIView for the current screen.
Hand the screenshot to the modal view (I used a property)
Present the modal view
In the modal view controller's viewDidAppear, set the image as UIImageView at index 0. Adjust the vertical position of the image by the height of the status bar.
In the modal view controller's viewWillDisappear, remove the image again
The effect is:
The view animates in as any modal view does - the semi transparent parts of the modal view glide over the existing view
As soon as the animation stops, the background is set to the screenshot - this makes it appear as if the old view is still underneath even though it isn't.
As soon as the modal view's disappear animation starts, the image is removed. The OS meanwhile shows the old navigation view so the modal view transparently glides away and out of sight as you'd expect.
I tried animating in my own overlay view but it didn't work very well. I got a crash with no indication as to what has crashed. Rather than chase this down I did the bg view & Works really well.
Code in the modal view - I think you can figure out the rest, namely setting the property modalView.bgImage...
- (void)viewDidAppear:(BOOL)animated {
// background
// Get status bar frame dimensions
CGRect statusBarRect = [[UIApplication sharedApplication] statusBarFrame];
UIImageView *imageView = [[UIImageView alloc] initWithImage:self.bgImage];
imageView.tag = 5;
imageView.center = CGPointMake(imageView.center.x, imageView.center.y - statusBarRect.size.height);
[self.view insertSubview:imageView atIndex:0];
}
- (void)viewWillDisappear:(BOOL)animated {
[[self.view viewWithTag:5] removeFromSuperview];
}
self.modalPresentationStyle = UIModalPresentationCurrentContext;
[self presentModalViewController:newview animated:YES];
and make sure you setup the modal view background to be transparent,
self.view.background = .... alpha:0.x;
if you set modalPresentationStyle for the modal view controller to:
viewController.modalPresentationStyle = 17;
The view in the background is not removed. (TWTweetComposeViewController use it).
I did not try to pass App Store review with this code though
This post about displaying a semi-transparent "Loading..." view might give a few pointers on how to proceed.
Yeah, you have to add the view manually, and if you want to slide in from the bottom or whatever you have to do the animation yourself too.
I wrote a class to do this, and a semi-modal datepicker using that class as an example.
You can find documentation in this blog post, the code is on github
I've been researching this same issue for the past week. I tried all the various answers and examples found in Google and here on StackOverflow. None of them worked that well.
Being new to iOS programming, I wasn't aware of something called UIActionSheet. So if you're trying to accomplish this in order to show a modal overlay of buttons (such as a modal asking someone how they want to share something), just use UIActionSheet.
Here is a webpage that shows an example of how to do this.
I got this idea from https://gist.github.com/1279713
Prepare:
In the modal view xib (or scene using storyboard), I setup the full-screen background UIImageView (hook it with the .h file and give it a property "backgroundImageView") with 0.3 alpha. And I set the view (UIView) background color as plain black.
Idea:
Then in "viewDidLoad" of the modal view controller I capture the screenshot from the original status and set that image to the background UIImageView. Set the initial Y point to -480 and let it slide to Y point 0 using 0.4-second duration with EaseInOut animation option. When we dismiss the view controller, just do the reverse thing.
Code for the Modal View Controller Class
.h file:
#property (weak, nonatomic) IBOutlet UIImageView *backgroundImageView;
- (void) backgroundInitialize;
- (void) backgroundAnimateIn;
- (void) backgroundAnimateOut;
.m file:
- (void) backgroundInitialize{
UIGraphicsBeginImageContextWithOptions(((UIViewController *)delegate).view.window.frame.size, YES, 0.0);
[((UIViewController *)delegate).view.window.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage * screenshot = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
backgroundImageView.image=screenshot;
}
- (void) backgroundAnimateIn{
CGRect backgroundImageViewRect = backgroundImageView.frame;
CGRect backgroundImageViewRectTemp = backgroundImageViewRect;
backgroundImageViewRectTemp.origin.y=-480;
backgroundImageView.frame=backgroundImageViewRectTemp;
[UIView animateWithDuration:0.4 delay:0.0 options:UIViewAnimationCurveEaseInOut animations:^{
backgroundImageView.frame=backgroundImageViewRect;
} completion:^(BOOL finished) {
}];
}
- (void) backgroundAnimateOut{
CGRect backgroundImageViewRect = backgroundImageView.frame;
backgroundImageViewRect.origin.y-=480;
[UIView animateWithDuration:0.4 delay:0.0 options:UIViewAnimationCurveEaseInOut animations:^{
backgroundImageView.frame=backgroundImageViewRect;
} completion:^(BOOL finished) {
}];
}
In viewDidLoad, simply call:
[self backgroundInitialize];
[self backgroundAnimateIn];
In anywhere we dismiss the modal view controller, we call:
[self backgroundAnimateOut];
Please note that this will ALWAYS animate the background image. So if this modal view controller transition style (or the segue transition style) is not set to "Cover Vertical", you may not need to call the animation methods.
I finally accomplished this, for a navigation or tab bar interface, by combining an overlay view controller (see: pix0r's answer) that's hidden / un-hidden before hiding or showing a view controller based on this very good blog post.
Concerning the view controller, the tip is to make its background view the clearColor, then the semi-transparent overlay view is visible and whatever views are added as subviews in the view controller are in front and most importantly opaque.
I've created open soruce library MZFormSheetController to present modal form sheet on additional UIWindow. You can use it to present transparency modal view controller, even adjust the size of the presented view controller.
For iOS 8+ you can use UIModalPresentationOverCurrentContext presentation style for presented view controller to easy achieve desired behavior.
UIViewController *viewController = [[UIViewController alloc] init];
viewController.view.backgroundColor = [[UIColor blackColor] colorWithAlphaComponent:0.9f];
viewController.modalPresentationStyle = UIModalPresentationOverCurrentContext;
[self presentViewController:viewController animated:YES completion:nil];
If you also need to support iOS 7 - check this thread.
You can achieve transparent/semi-transparent modal view effect by overlaying a transparent/semi-transparent button on both the view and the navigation bar.
You can access the navigation bar through the navigationBar property of the UINavigationController.
I found that UIButton unlike UILabel will trap mouse events - hence giving the correct modal behavior.
I just found a workaround for that. Just create a 1X1 of UIViewController and add it to your parent view controller. And show the transparent modal view controller in that UIViewController.
on viewDidLoad;
self.dummyViewController = [[UIViewController alloc] init];
[self.dummyViewController.view setFrame:CGRectMake(0, 0, 1, 1)];
[self.view addSubView:self.dummyViewController.view];
when you need to open a transparentViewController;
[self.dummyViewController presentModalViewController:yourTransparentModalViewController animated:true];
If you need a screen like the attached one, the below code may help you.
The code:
MyViewController * myViewController = [[MyViewController alloc] initWithNibName:nibName bundle:nil];
UINavigationController * myNavigationController = [[UINavigationController alloc] initWithRootViewController: myViewController];
myNavigationController.modalPresentationStyle = UIModalPresentationPageSheet;
[self presentModalViewController: myNavigationController animated:YES];
If say you want a screen overlay, use the parentViewController.view, it will place above navigation bar ++
MyCustomViewController* myOverlayView = [[MyCustomViewController alloc] init];
[self.parentViewController.view addSubview:myOverlayView];
This worked for me:
UIViewController *modalViewController = [[UIViewController alloc] init];
modalViewController.view.backgroundColor = [UIColor whiteColor] colorWithAlpha:0.5];
[self showDetailViewController:modalViewController sender:nil];