I want to create a different class with a view and call that class on screen.
When I run the app, the view does not appear. If I delete that structure and create the button on the main file, it works fine. When I put it on a different class, it does not work.
MyView.h
#import <UIKit/UIKit.h>
#interface viewHome : UIViewController
-(UIView*) myHome;
#end
MyView.m (Creating a button for test)
#import "viewHome.h"
#implementation viewHome
-(UIView*) myHome {
UIView * myScreen = [[UIView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]];
myScreen.backgroundColor = [UIColor whiteColor];
UIButton * myButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
myButton.frame = CGRectMake(100,100,100,44);
[myButton setTitle:#"Login" forState:UIControlStateNormal];
[myScreen addSubview:myButton];
return myScreen;
}
#end
viewController.m
[...]
- (void)viewDidLoad
{
[super viewDidLoad];
viewHome * fncScreen;
UIView * homeScreen = [fncScreen myHome];
[self.view addSubview:homeScreen];
}
Thanks
Its a bad practice to add one viewController's view as a subview to an another viewcontroller. (unless you are using certain classes/methods that let you have childViewControllers).
Its exactly for this reason, your view doesn't appear in one case, and appears in the other case.
try adding the -(UIView*) myHome method in your viewController.m, and do a
[self.view addsubview: [self myHome]];
here's a good SO post about Nested UIViewControllers:
Is it wise to "nest" UIViewControllers inside other UIViewControllers like you would UIViews?
You could call the method [fncScreen myHome] after allocation your view homeScreen.
like this -
UIView *homeScreen = [[UIView alloc] init];
homeScreen = [funScreen myHome];
[self.view addSubView: homeScreen];
[homeScreen release];
Hope this will help you.
One obvious mistake I see in your code is this line:
viewHome * fncScreen;
OK, that's a pointer declaration, but you didn't actually create the object.
You need something like this:
viewHome * fncScreen = [[viewHome alloc] init];
Then you can call methods on such initialized object.
I have an app that I am working on, and in an effort to save on views that I make, I want to be able to dynamically pass the view an image. So for example, I make a view:
FlipsideViewController *controller = [[FlipsideViewController alloc] initWithNibName:#"FlipsideView" bundle:nil];
Then I want to set the image that the view's imageview shows before I present it:
UIImage *image = [UIImage imageNamed: #"IMG_5010_2.jpg"];
[controller.imageView setImage:image];
[controller.label setText:#"HI"];//I am trying to do this too and it isn't working...
But it just isn't working!! Does anyone have any thoughts on this? Please help!!
Thanks
NOTE: I do have UIImageView and UILabel attributes set on the view I am trying to present...
You should set the image within viewDidLoad method of the relevant UIViewController as the view won't exist during the init phase and will have been displayed by the time viewDidAppear is called.
Perhaps you could try this:
add two new properties to your FlipsideViewController:
#property (retain) UIImage *image;
#property (copy) NSString *labelText;
Don't forget to synthesize them in your FlipsideViewController.m.
Then when you instantiate your FlipsideViewController:
FlipsideViewController *controller = [[FlipsideViewController alloc] initWithNibName:#"FlipsideView" bundle:nil];
UIImage *image = [UIImage imageNamed: #"IMG_5010_2.jpg"];
controller.image = image;
controller.labelText = #"Hi";
and then in your FlipsideViewController viewDidLoad method you can assign the values in the properties to the view IBOutlets:
- (void)viewDidLoad {
//do other stuff
[self.imageView setImage:self.image];
[self.label setText:self.labelText];
//any other stuff
}
Sure you've got your IBOutlets hooked up properly in the nib file?
Assuming you've put this code in the right place in your view controller, this should be working fine. So it's either you're not in a place that this code is getting run, or the things you're configuring aren't hooked to any objects in the nib. It has to be one of those two things.
I have a viewcontroller which contains an instance variable containing a dictionary object with a bunch of data. The view is fairly complex and contains several subviews that i instantiate and embed from seperate view files(To avoid having a thousand lines of UI code in the actual viewcontroller) - But how do these subviews, which exists in their own files, get access to my dictionary object from the viewcontroller?
So when im editing the DescriptionView.m file - How do i get access to the contents of the locationData dictionary object from the ViewController?
Hope you understand what i mean.
Here's a snippet from the ViewController:
CaseViewController.h
#import "DescriptionView.h"
#interface CaseViewController : UIViewController {
NSDictionary *locationData;
DescriptionView *descriptionView;
}
#property (nonatomic, retain) NSDictionary *locationData;
#property (nonatomic, retain) DescriptionView *descriptionView;
#end
CaseViewController.m
- (void)loadView {
UIView *view = [[UIView alloc] init];
descriptionView = [[DescriptionView alloc] initWithFrame:CGRectMake(0, 130, 320, 237)];
descriptionView.hidden = NO;
[view addSubview:descriptionView];
self.view = view;
[view release];
}
Ideally you should never access any properties of viewcontroller from the view.
The main idea of MVC architecture is that viewcontroller tells it's views what to render and not vise versa.
So you just have to provide all the data that your view needs for rendering during it's initialization:
- (void)loadView {
UIView *view = [[UIView alloc] init];
descriptionView = [[DescriptionView alloc] initWithFrame:CGRectMake(0, 130, 320, 237) paramDict: self.locationData]; descriptionView.hidden = NO;
[view addSubview:descriptionView];
[descriptionView release]; // BTW add this line here (or in dealloc) or you'll have a leak
self.view = view; [view release];
}
If you need to update your view dynamically, then you should add some methods to your view and call them from viewcolnroller.
E.g.:
DescriptionView.m:
-(void) updateWithDict:(NSDictionary*) udict;
If you need to perform some actions when some button in DescriptionView is pressed (or any other user interaction) a good idea would be declaring a protocol like DescriptionViewDelegate (or smth like that):
-(void) descriptionViewButton1Pressed:(DescriptionView*) dview;
-(void) descriptionViewButton2Pressed:(DescriptionView*) dview;
then make your CaseViewController a delegate and implement that methods there.
The simpliest way to have a reference to its viewcontroller from a view is to extend UIView:
#interface MyView: UIView {
UIViewController *mViewController;
}
Then in loadView
MyView *view = [[MyView alloc] init];
view.mViewController = self;
I have a custom UIView called TiledImage which has a single property named tiledImage and a custom drawRect method. I add this view to my ViewController, but when the ViewController is deallocated the dealloc for this view is never being called, even though I am releasing the view and setting it to nil. What could be causing this? I don't have any other references to the view, so my understanding is that it should release correctly.
This is how I add the view to my view controller:
NSString *imagePath = [[NSBundle mainBundle] pathForResource:#"tile" ofType:#"png"];
UIImage *image = [[UIImage alloc] initWithContentsOfFile:imagePath];
self.backImageView = [[TiledImage alloc] initWithFrame:IMAGE_FRAME];
self.backImageView.tiledImage = image;
[self.view addSubview:self.backImageView];
[self.view sendSubviewToBack:self.backImageView];
[image release];
And in my ViewController's dealloc method I have this:
_backImageView.tiledImage = nil, [_backImageView release], _backImageView = nil;
That line of code is hit, but dealloc is never called on TiledView. Note that _backImageView is the var that the property backImageView uses.
Can someone give me ideas on what I may be doing wrong that is preventing the dealloc on the TiledImage object from being called?
If self.backImageView is a retain property, you have a memory leak - the TiledImage has a retain count of 1 prior to invoking the setter, 2 afterwards.
Your code for adding the view should look like e.g. the following instead:
TiledImage *imageView = [[TiledImage alloc] initWithFrame:IMAGE_FRAME];
self.backImageView = imageView;
[imageView release];
I've been trying to set up a custom background for the whole of my NavigationBar (not just the titleView) but have been struggling.
I found this thread
http://discussions.apple.com/thread.jspa?threadID=1649012&tstart=0
But am not sure how to implement the code snippet that is given. Is the code implemented as a new class? Also where do I instatiate the UINavigationController as I have an application built with the NavigationView template so it is not done in my root controller as per the example
Uddhav and leflaw are right. This code works nicely:
#interface CustomNavigationBar : UINavigationBar
#end
#implementation CustomNavigationBar
-(void) drawRect:(CGRect)rect
{
UIImage *image = [UIImage imageNamed: #"myNavBarImage"];
[image drawInRect:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];
}
#end
// this can go anywhere
+(UINavigationController*) myCustomNavigationController
{
MyViewController *vc = [[[MyViewController alloc] init] autorelease];
UINavigationController *nav = [[[NSBundle mainBundle] loadNibNamed:#"CustomNavigationController" owner:self options:nil] objectAtIndex:0];
nav.viewControllers = [NSArray arrayWithObject:vc];
return nav;
}
You have to create CustomNavigationController.xib and put a UINavigationController in it and change the navigationBar class to "CustomNavigationBar".
You must use the 'appearance' proxy to change the background and other styling properties of controls such as UINavigationBar, UIToolBar etc. in iOS 5.xx. However, these are not available for iOS 4.xx so for backwards compatibility, you need a hybrid solution.
If you want to support both iOS 4.xx and iOS 5.xx devices (i.e. your DeploymentTarget is 4.xx), you must be careful in wrapping the call to the appearance proxy by checking at runtime if the 'appearance' selector is present or not.
You can do so by:
//Customize the look of the UINavBar for iOS5 devices
if ([[UINavigationBar class]respondsToSelector:#selector(appearance)]) {
[[UINavigationBar appearance] setBackgroundImage:[UIImage imageNamed:#"NavigationBar.png"] forBarMetrics:UIBarMetricsDefault];
}
You should also leave the iOS 4.xx workaround that you may have implemented. If you have implemented the drawRect workaround for iOS 4.xx devices, as mentioned by #ludwigschubert, you should leave that in:
#implementation UINavigationBar (BackgroundImage)
//This overridden implementation will patch up the NavBar with a custom Image instead of the title
- (void)drawRect:(CGRect)rect {
UIImage *image = [UIImage imageNamed: #"NavigationBar.png"];
[image drawInRect:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];
}
#end
This will get the NavBar look the same in both iOS 4 and iOS 5 devices.
You just have to overload drawRect like that :
#implementation UINavigationBar (CustomImage)
- (void)drawRect:(CGRect)rect {
UIImage *image = [UIImage imageNamed: #"NavigationBar.png"];
[image drawInRect:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];
}
#end
Implementing a category is not advisable. iOS5 may provide relief for this issue. But for old APIs, you can -
Subclass UINavigationBar to say CustomNavBar and implement the custom drawRect from Lithium's answer.
For all IB based UINavigationControllers, provide CustomNavBar as custom class for their UINavigationBar.
For all code based UINavigationControllers. Create a XIB with a UINavigationController and do step two. Then provide a factory method in code that loads the UINavigationController from the nib and provide an IBOutlet.
Eg.
[[NSBundle mainBundle] loadNibNamed:#"CustomNavigationController" owner:self options:nil];
UINavigationController *navController = self.customNavigationController;
navController.viewControllers = [NSArray arrayWithObject:controller]
You can also override the drawLayer:inContext: method in a UINavigationBar category class. Inside the drawLayer:inContext: method, you can draw the background image you want to use.
- (void) drawLayer:(CALayer *)layer inContext:(CGContextRef)context
{
if ([self isMemberOfClass:[UINavigationBar class]] == NO) {
return;
}
UIImage *image = (self.frame.size.width > 320) ?
[UINavigationBar bgImageLandscape] : [UINavigationBar bgImagePortrait];
CGContextClip(context);
CGContextTranslateCTM(context, 0, image.size.height);
CGContextScaleCTM(context, 1.0, -1.0);
CGContextDrawImage(context, CGRectMake(0, 0, self.frame.size.width, self.frame.size.height), image.CGImage);
}
And as a complete demo Xcode project on customizing the appearance of UINavigationBar this and this might be helpful.
Implementing a category won't work in iOS5, you should use Uddhav Kambli's advice for using CustomNavbar on iOS ≤ 5.
I just found this blog entry, describing this topic very simple: http://web0.at/blog/?p=38
it helped me a lot, they use the "drawRect" method to get the customisation of the background.
To all those who are having trouble with UINavigationBar custom backgrounds in iOS5, do this in the corresponding viewDidLoad methods:
#if defined(__IPHONE_5_0) && __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_5_0
if ([self.navigationController.navigationBar respondsToSelector:#selector( setBackgroundImage:forBarMetrics:)]){
[self.navigationController.navigationBar setBackgroundImage:[UIImage imageNamed:#"TitleBar"] forBarMetrics:UIBarMetricsDefault];
}
#endif
Notice that in my case, the background image was named "TitleBar". You can put whatever your custom background image name is.
The problem you'll have is that if you use a navigation controller, the title of each page will overlay your custom navbar. If your navbar contains a logo or the name of your app, this is obviously unacceptable.
You could set the title of each view in your navigation stack to blank, but some views force a title that you can't do anything about (like the photo picker). So you might want to create an alternate navbar image with the same color or design as your logo navbar, but with a blank area to make room for overlaid titles.
To switch navbar images at will, add a property to your app delegate to hold the name of the navbar image and replace the first line of the first example above with these two:
YourAppDelegate* theApp = (YourAppDelegate*)[[UIApplication sharedApplication] delegate];
UIImage* image = [UIImage imageNamed:theApp.navBarName];
Then in the first view controller that you'll push onto the navigation stack, do something like this:
- (void)viewWillAppear:(BOOL)animated
{
YourAppDelegate* theApp = (YourAppDelegate*)[[UIApplication sharedApplication] delegate];
theApp.navBarName = #"navBar_plain";
}
Then in the root view controller, do the same thing but specify your logo-bearing navbar image, so it gets restored when the user navigates back to it and there is no conflicting title.
Another approach is to Use UINavigationController's delegate.
It doesn't require subclassing/overwriting the UINavigationBar class:
/*
in the place where you init the navigationController:
fixer = [[AENavigationControllerDelegate alloc] init];
navigationController.delegate = fixer;
*/
#interface AENavigationControllerDelegate : NSObject <UINavigationControllerDelegate>
#end
#implementation AENavigationControllerDelegate
#define bgImageTag 143
- (void)navigationController:(UINavigationController *)navigationController
didShowViewController:(UIViewController *)viewController
animated:(BOOL)animated
{
//this is for the future for implementing with the appearance api:
if ([[navigationController navigationBar] respondsToSelector:#selector(setBackgroundImage:forBarMetrics:)])
{
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
[[navigationController navigationBar] setBackgroundImage:[UIImage imageNamed:#"header-logo-bg.png"]
forBarMetrics:UIBarMetricsDefault];
});
}
else
{
UIImageView* imageView = (UIImageView*)[navigationController.navigationBar viewWithTag:bgImageTag];
if(!imageView)
{
UIImage *image = [UIImage imageNamed:#"header-logo-bg.png"];
imageView = [[[UIImageView alloc] initWithImage:image] autorelease];
imageView.tag = bgImageTag;
}
[navigationController.navigationBar insertSubview:imageView atIndex:0];
}
}
#end
https://gist.github.com/1184147
In iOS5, zPosition value (of UINavigationBar's most depth layer) is changed. So if you change that zPosition, the old way works.
eg.
UINavigationBar *_bar = navigationController.navigationBar;
// Insert ImageView
UIImage *_img = [UIImage imageNamed:#"navibar.png"];
UIImageView *_imgv = [[[UIImageView alloc] initWithImage:_img] autorelease];
_imgv.frame = _bar.bounds;
UIView *v = [[_bar subviews] objectAtIndex:0];
v.layer.zPosition = -FLT_MAX;
_imgv.layer.zPosition = -FLT_MAX+1;
[_bar insertSubview:_imgv atIndex:1];
This script handle view's layer, so You should import QuartzCore.
Here is an alternative solution that lets you use your own custom subclass of UINavigationBar:
https://gist.github.com/1253807
As Apple itself has said, it is not correct to override methods in Categories. So the best way to customize the background of UINavigarionBar is subclassing and override -(void)drawInRect: method.
#implementation AppNavigationBar
- (void)drawRect:(CGRect)rect
{
UIImage *patternImage = [UIImage imageNamed:#"image_name.png"];
[patternImage drawInRect:rect];
}
To use this customized UINavigationBar it should be set as navigationBar property of your UINavigationBarController. As you know this property is readonly. So what should be done is:
- (void)viewDidLoad
{
[super viewDidLoad];
AppNavigationBar *nav = [AppNavigationBar new];
[self setValue:nav forKey:#"navigationBar"];
}
It works for both iOS 5 and 4.3.
You can subclass UINavigationBar and enable it like this, since categories for drawRect won't work in iOS5 anymore
navigationController = [[((^ {
NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:[NSKeyedArchiver archivedDataWithRootObject:navigationController]];
[unarchiver setClass:[SAPHUINavigationBar class] forClassName:#"UINavigationBar"];
[unarchiver setClass:[UIViewController class] forClassName:NSStringFromClass([navigationController.topViewController class])];
return unarchiver;
})()) decodeObjectForKey:#"root"] initWithRootViewController:navigationController.topViewController];
For a static view (no animation at all), I use the default iOS setBackgroundImage
But when I have a view that's animated (resize most likely), I create a custom UIImageView and add it to the navigationBar so that I have more flexibility over it
The thing is if you just add it, it will get on top of the buttons and the titleView, so I manually save a copy of most of subviews, remove them from parent view, add my imageView and than add all the subviews back
This works for me
UIImageView *navBackground = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"navigationBackgroundSample.jpg"]];
UIView *tempTitleView = [[self.navigationBar.subviews objectAtIndex:1] autorelease];
[[self.navigationBar.subviews objectAtIndex:1] removeFromSuperview];
[self.navigationBar addSubview:navBackground];
[self.navigationBar addSubview:tempTitleView];
self.navigationBar.clipsToBounds = YES;
[navBackground release];
In this case, I don't have buttons and I found out that my titleView is at index 1, if you have buttons, they should be around somewhere in the subviews array of navigationBar
I don't know what's at index 0, I don't know if this can work around the case you have text title neither...