I'd like to be able to create new UI elements (a UIProgressView bar) in a separate UIViewController every time a user taps on a button.
How would I go about doing this?
To create a UIProgressView programmatically, it is simply a matter of using alloc and init, setting a frame, and adding a subview, like so:
//.h
#import <UIKit/UIKit.h>
#interface ExampleViewController : UIViewController {
//create the ivar
UIProgressView *_progressView;
}
/*I like to back up my iVars with properties. If you aren't using ARC, use retain instead of strong*/
#property (nonatomic, strong) UIProgressView *progressView;
#end
//.m
#implementation
#synthesize progressView = _progressView;
-(void)viewDidLoad {
/* it isn't necessary to create the progressView here, after all you could call this code from any method you wanted to and it would still work*/
//allocate and initialize the progressView with the bar style
self.progressView = [[UIProgressView alloc]initWithProgressViewStyle:UIProgressViewStyleBar];
//add the progressView to our main view.
[self.view addSubview: self.progressView];
//if you ever want to remove it, call [self.progressView removeFromSuperView];
}
Read this guide https://developer.apple.com/library/ios/#DOCUMENTATION/WindowsViews/Conceptual/ViewPG_iPhoneOS/CreatingViews/CreatingViews.html
Most of the UI elements create like this:
UIView *view = [[UIView alloc] initWithFrame:CGRect];
// set the property of the view here
// ...
// finally add your view
[ViewController.view addSubView:view];
Related
I want to make an Advertising banner in my app. A bit like iAd's.
I was going to make it by having a UIImage on the view then assigning the banner image. I would then add a touch gesture so the user could click it and go to another view in my app. I Know That I can do this on one view quite easily but I want this to be on most views in the app. Whats the best way for adding the banner to more than one view with out writing the same code more that once?
The below design shows the sort of banner im after.
Thanks
#import <UIKit/UIKit.h>
#class custom;
#protocol adDelegate
- (void)viewAd:(NSString *)adRate;
#end
#interface custom : UIView
#property (strong, nonatomic) UIImage *viewImage;
#property (assign) id <adDelegate> delegate;
#end
// Main class
#import "custom.h"
#implementation custom
#synthesize viewImage;
#synthesize delegate;
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
UIImageView *imageView = [[UIImageView alloc] initWithFrame:frame];
imageView.image = viewImage;
[self addSubview:imageView];
}
return self;
}
- (id)initWithCoder:(NSCoder *)aDecoder
{
if ((self = [super initWithCoder:aDecoder]))
{
}
return self;
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
[self.delegate viewAd:#"view"];
}
You can Create a UIView Class and call it BannerView for instance.
// in the bannerView.h
#import <UIKit/UIKit.h>
#interface BannerView : UIView{
UIImageView* bannerImage;
}
#property(nonatomic,retain) UIImageView* bannerImage;
#end
//in the bannerView.m
#import "BannerView.h"
#implementation BannerView
#synthesize bannerImage;
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
}
return self;
}
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
// Drawing code
bannerImage=[[UIImageView alloc]initWithImage:[UIImage imageNamed:#"banner-image.png"]];
bannerImage.frame=CGRectMake(0, 0, 320, 100);
[self addSubview:bannerImage];
// add a uibutton on top of the uiimageview and assign an action for it
// better than creating an action recogniser
UIButton* actionButton=[UIButton buttonWithType:UIButtonTypeCustom];
actionButton.frame=CGRectMake(0, 0, 320, 100);
[actionButton addTarget:self action:#selector(yourAction) forControlEvents:UIControlEventTouchUpInside];
[self addSubview:actionButton];
}
-(void) yourAction{
// do what ever here like going to an other uiviewController as you mentionned
}
#end
Now you can call this view from any View Controller this way
BannerView* banner=[[BannerView alloc] initWithFrame:CGRectMake(0, 300, 320, 100)];
[self.view addSubview:banner];
Try creating a parent class from UIView where you do all the display and handling of the banner using your UIImageView and gesture recognizers. Then whichever views need this functionality, derive them from this parent class, and override default handling in method so that you can customize the behavior in your child class.
A few suggestions:
First, why not just use a UIButton instead of a UIImage with a Gesture? All you're really doing is replicating button functionality after all...
Second, I'd probably tackle the overall problem by creating a class that includes the UIButton, like so:
#interface YourSuperViewController : UIViewController
#property (nonatomic, strong) IBOutlet UIButton *adButton;
- (IBAction)adTouched:(id)sender;
#end
In the viewDidLoad for this class, create the button, and add it to the view, and add your ad-specific logic to the adTouched action.
Then create the rest of the views in your app as an instance of YourSuperViewController. Like so:
#interface SomeOtherViewController : YourSuperViewController
Now the SomeOtherViewController will auto-magically have the ad button and respond to a touch on it properly. Done!
What everyone else has said is the best way. If you need custom functionality, subclassing is probably the way to go.
I just wanted to add one pedantic thing. Its important to remember that a UIImage is not a view. There has never been a UIImage on the screen, ever. A UIImage is a model object. It is just a collection of data. A UIImageView is a view object and as such, a UIImageView can display itself on the screen.
This might seem overly pedantic and nitpicky, but its important to have these things sorted out in our heads in order to effectively use MVC (model, view, controller)
I'm developing the iPhone app. I custom defined the titleview for navigation bar. The title view contains a button, I also defined the delegate method to support the button click event. But when the button clicked, the delegate cannot be executed. I am not sure why ?
Below as my codes:
UPDelegate.h
#protocol UPDelegate <NSObject>
#optional
-(void)buttonClick;
#end
TitleView.h
#import <UIKit/UIKit.h>
#import "UPDelegate.h"
#interface TitleView :UIView
#property (nonatomic, unsafe_unretained) id<UPDelegate> delegate;
-(id)initWithCustomTitleView;
#end
TitleView.m
#synthesize delegate;
-(id)initWithCustomTitleView
{
self = [super init];
if (self) {
UIButton *titleButton = [UIButton buttonWithType:UIBUttonTypeCustom];
titleButton.frame = CGRectMake(0, 0, 20, 44);
[titleButton setTitle:#"ABC" forState:UIControlStateNormal];
// add action
[titleButton addTarget:delegate action:#selector(buttonClick) forControlEvents:UIControlEventTouchUpInside];
[self addSubview:titleButton];
}
return self;
}
In my ViewController, i implement the protocal as below:
MyViewController.h
#interface MyViewController : UIViewController<UPDelegate>
and in the .m file, i wrote the delegate method, but cannot be exeucte.
MyViewController.m
-(void)buttonClick{
NSLog("click title button");
}
You have to set your delegate, from you code sample you are creating id<UPDelegate> delegate; in your titleView class.
So in your MyViewController where you have added <UPDelegate>, create an instance of TitleView and set delegate to self.
So in your MyViewController use:
TitleView*titleView=[[TitleView alloc]init];
titleView.delegate=self;
It sounds like you have not set the value of your titleView's delegate property, so any messages sent to the delegate property are ignored because the delegate is nil.
You should make sure that you are setting your titleView's delegate to be your MyViewController. The best place to do this is most likely in your MyViewController's viewDidLoad: method.
Did you set the delegate anywhere? Because you have to set the delegate of your TitleView to MyViewController:
titleView.delegate = self;
I am building a utility-based application, the data is stored in the MainViewController, and now I know how to pass data to the FlipsideViewController (many regards to this thread BTW, Sending data from Mainview to Flipside?). But I am getting the data onto an subview (subclass of UIView) that I have added to the flipside view. How can I pass data to this subview? I saw there is already a delegate and protocol set up in the FlipsideViewController.h, I am really new to the delegate sort of things. Any help would be greatly appreciated!
Updates:
On the main view, I have a couple of text fields for users to input to create an object. All the objects are stored in an array. Namely, my data is created and stored in the MainViewController. Now on the flip side, I have a custom UIView subclass which allows me to do my own drawing based on the data in that array. What I need to do here is pass the data that stored in MainViewController to this subview. Here is my relevant code:
In the MainViewController.m
- (IBAction)showInfo:(id)sender {
FlipsideViewController *controller = [[FlipsideViewController alloc] initWithNibName:#"FlipsideView" bundle:nil];
controller.delegate = self;
controller.receiver = data;//this is what I've done.
controller.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentModalViewController:controller animated:YES];
[controller release];
}
In the FlipsideViewController.h
#protocol FlipsideViewControllerDelegate;
#interface FlipsideViewController : UIViewController {
id <FlipsideViewControllerDelegate> delegate;
DataModel *receiver; //create a property to receive the data transferred from main view
}
#property (nonatomic, assign) id <FlipsideViewControllerDelegate> delegate;
#property (nonatomic, retain) DataModel *receiver;
- (IBAction)done:(id)sender;
#end
#protocol FlipsideViewControllerDelegate
- (void)flipsideViewControllerDidFinish:(FlipsideViewController *)controller;
#end
In the above code, "data" is an DataModel object declared in the MainViewController.h file.
And I want to do my custom drawing in drawing class (subclass of UIView), how can I pass data from the FlipsideViewControllerto this subview? Do I need to make use of delegate declared in the FlipsideViewController.h file? Thanks in advance!
I have had a quick look at the template and think you are getting confused with what the delegate is being used for.
The delegate in this template is not transferring data. When you have clicked the done button it calls back to MainViewController and asks it to call the dismissModalViewControllerAnimated method so that it can remove the view controller. This seems a bit superflous as the documentation states
If you call this method on the modal view controller itself, however, the modal view controller automatically forwards the message to its parent view controller.
Therefore you don't really need to call the parent to do this.
In Interface builder you can see that the FlipsideView.xib has it's File's Owner set to FlipsideViewController.xib.
Now if you right click the File's Owner you will see that view is connected to View this basically means that view is the name of the property in FlipsideViewController and View is the element in Interface Builder.
Therefore we can access elements in the xib file from FlipsideViewController using outlets.
To say draw a label you will need to do a couple of things
First add a property in the .h and synthesize it in the .m like
// FlipsideViewController.h
#interface FlipsideViewController : UIViewController
#property (nonatomic, retain) IBOutlet UILabel *testLabel; // <----- Added this
#property (nonatomic, assign) id <FlipsideViewControllerDelegate> delegate;
- (IBAction)done:(id)sender;
#end
// FlipsideViewController.m
#implementation FlipsideViewController
#synthesize delegate = _delegate;
#synthesize testLabel = _testLabel; // <----- Added this
// More methods
- (void)dealloc
{
[_testLabel release]; // Always do you memory management
[super dealloc];
}
Then back in Interface Builder
Add a UILabel element to your view
ctrl + drag from File's Owner to the UILabel you added
Select the label in my example it is testLabel
Now these are hooked up correctly. The place where you want to be setting the value of the label is in viewDidLoad: which you can now do like this
- (void)viewDidLoad
{
[super viewDidLoad];
self.testLabel.text = #"It Works"; // You would use the data passed in from `MainViewController`
}
I find the easiest way to pass data from one view to another is by directly setting the data in the next view from the original view.
For example;
In your FlipsideViewController.h, declare a 'container' for the data you want to pass. It must be the same class on both sides to work properly, ie. NSArray to NSArray, NSMutableDictionary to NSMutableDictionary.
NSMutableArray *newData;
...
#property (nonatomic, retain) NSMutableArray *newData; // This allows you to access this object from outside this class.
and in FlipsideViewController.m
#synthesize newData;
...
[newData release];
Now we need to pass the data, so to speak. Let's say the data we want to 'send' is stored in a NSMutableArray called 'results'.
In our MainViewController.m, when we are instantiating our next view controller (in this case FlipsideViewController) we can directly reference the newData mutable array after we initalize the nib.
FlipsideViewController *controller = [[FlipsideViewController alloc] initWithNibName:#"FlipsideView" bundle:nil];
controller.newData = results;
controller.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentModalViewController:controller animated:YES];
[controller release];
Make sure you are importing your FlipsideViewController in your MainViewController.h file.
If the property is declared in your .h file, you can pretty much reference the contents of the object from anywhere within the view stack!
Hope that helps :D
I'm my class i've added a an instance of my view controller, created a property and then synthesized it in my implementation file. I am trying to update the UIlabel in the view controller like this,
NSString *currentChar = [[NSString alloc] initWithFormat:#"%c", ch];
viewController.outputLabel.text = currentChar;
[currentChar release];
My problem is that everything builds without any errors or warnings but the label just doesn't get updated, what am I doing wrong. I'd really appreciate some help on this one.
Are you sure you're referencing the existing viewController and you didn't instantiate a new one? Your property is not declared as copy, correct?
textProcessor.h / .m
#interface textProcessor : NSObject {
MainViewController *mainView;
}
#property (retain) MainViewController *mainView;
#end
#implementation textProcessor;
#synthesize mainView;
MainViewController.h / .m
#interface MainViewController : UIViewController {
UILabel *myLabel;
}
#property (retain) UILabel myLabel;
#end
#implementation MainViewController
#synthesize myLabel;
When you are initializing your textProcessor class, and you set the value for "mainView" like
-(void)viewDidLoad {
[super viewDidLoad];
textProcessor *proc = [[textProcessor alloc] init];
proc.mainView = self;
//note that you are not doing this:
//MainViewController *mainView = [[MainViewController alloc] init];
//proc.mainView = mainView;
//that was creating a new instance variable instead of using self, the existing one
[textProcessor release];
}
Have you created your label in IB? If you are using IB you have to create an IBOutlet for your UILabel. You then make a connection between the UILabel in IB to your IBOutlet in your class.
Have you tried calling the setNeedsDisplay method on the view? Also you may want to try using the setText method instead of assigning directly to the property.
I had thought I actually had a pretty good handle on the whole view controller model, but something just doesn't seem to making much sense for me. My main issue is with adding a custom UIView subclass as a property of a UIViewController subclass.
Whenever I assign a valid instance of a UIView subclass to that property, nothing happens or the code crashes.
Here's a quick outline:
The main controller inits its own view and that loads fine.
I can then add this UIView subclass to the main controller by instantiating it and addSubview:ivar etc. No problems there...
However... if I wanted to have this custom UIView as a property of the ViewController, that does not seem to work. Can anyone shed some light?
Here's a code summary:
#interface CustomUIView : UIView { }
.
#interface MainViewController : UIViewController {
CustomUIView *someOtherView;
}
#property (nonatomic, copy) CustomUIView *someOtherView;
...
- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor greenColor]; // the default controller view
CustomUIView *tmpView = [[CustomUIView alloc] initWithFrame:CGRectMake(0,0,320,480)];
[self.view addSubview:tmpView]; // this works
self.someOtherView = tmpView; // this does NOT work and
self.view = self.someOtherView; // ultimately, this is what i'm after
[tmpView release];
}
Many thanks to this wonderful community!
You can't copy UIViews. Or UIView subclasses. Try retain, instead.