I am a mere beginner in iOS. I have seen this statement ** [leftSwitch setOn:setting animated:YES];** in a tutorial describing about switches.
UISwitch *leftSwitch;
UISwitch *whichSwitch = (UISwitch *)sender;
BOOL setting = whichSwitch.isOn;
[leftSwitch setOn:setting animated:YES];
Please explain me the need of keyword animated in this context.Thanks in advance
in objC, parameters dont come behind the method name like in C or java or ...
in objC, parameters are interwoven with the method name..
lalalaa:PARAM lalala:PARAM2 lalala:PARAM3
after every : comes a ONE param
so animated: = part of method name
setOn:animated:
The animated part of that method determines where the changing of that switch state is a nice smooth animation or not. Try both YES and NO and you will see.
setOn:animated:
Set the state of the switch to On or Off, optionally animating the transition.
(void)setOn:(BOOL)on animated:(BOOL)animated
Parameters
on
YES if the switch should be turned to the On position; NO if it should be turned to the Off position. If the switch is already in the designated position, nothing happens.
animated
YES to animate the “flipping” of the switch; otherwise NO.
SEE: http://developer.apple.com/library/ios/#documentation/uikit/reference/UISwitch_Class/Reference/Reference.html
Drag and drop UISwitch in xib file.
In .h file:
IBOutlet UISwitch *onoff;
In .m file:
[onoff addTarget:self action:#selector(switchTapped:) forControlEvents:UIControlEventValueChanged];
// Switch
-(void) switchTapped: (id) sender {
UISwitch *switchControl = (UISwitch*) sender;
BOOL value = switchControl.isOn;
if (value) {
lbl4.text=#"ON";
}else{
lbl4.text=#"OFF";
}
}
Related
I have a UIButton. I bound a target as follows.
[button addTarget:self action:#selector(myFunction)
forControlEvents:UIControlEventTouchUpInside];
When i click my Button multiple times quickly it invoke the target function multiple times.
On Tapping button i present a new View controller.
when i click 3 times quickly then my new view controller is shown 3 times.
This is something stupid. Whats the point of triggering the function again once the View has been shifted to a new View controller. Why the Hell Apple do such stupid things ?
Any Help please?
First of all its not apple bugs. It should be handle manually. So follow these step
First make your global instance of your button then do this
.h file
#property (weak, nonatomic) IBOutlet UIButton *btn;
.m file
- (IBAction)myFunction:(id)sender
{
self.btn.userInteractionEnabled = NO;
}
-(void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
self.btn.userInteractionEnabled = YES;
}
Take one global bool flag like "isItDone" or it declare in singleton class.
in "myFunction" set it as false
which View controller you push on that function in that class's "ViewDidAppear" method set as true.
it will help you.
I have same problem and it is good solution for that to manage it using one global variable.
I think this will help you.
Change your calling function like this
- (IBAction)myFunction:(id)sender
{
UIButton *button = (UIButton*)sender;
button.userInteractionEnabled = NO;
}
and call your function like this
[button addTarget:self action:#selector(myFunction:)
forControlEvents:UIControlEventTouchUpInside];
if you want to store the selection incase you came back to the view controller then only you need to keep a boolean flag to store if its clicked once or not.
Set the IBOutlet to your button, in the viewWillAppear method write,
button.userInteractionEnabled = YES;
and when you click on the button set,
button.userInteractionEnabled = NO;
I have a UITableView that i would like to hide until the user taps the button searchButtonTapped. (I'm also using this button as an IBAction.)
Originally i'm hiding the table view as you see in the viewDidLoad, and i wanna show it after the button was tapped, but it does not shown up after i tap the search button. Do i missed something? For me, it seems it should be work properly, after the button was tapped i refresh the table view.
my .h file
#property (weak, nonatomic) IBOutlet UIButton *searchButtonTapped;
- (IBAction)searchButton:(id)sender;
.m file
- (void)viewDidLoad
{
[super viewDidLoad];
self.tableView.hidden = YES;
}
- (void)buttonTapped:(id)sender {
if (sender == self.searchButtonTapped) {
self.tableView.hidden = NO;
[self.tableView reloadData];
}
}
- (IBAction)searchButton:(id)sender {
[self searchSetup];
}
It's impossible to tell from the little bit of code that you posted. Add NSLog statements in your buttonTapped method that show entering the method, entering the if statement, the value of searchButtonTapped, and the value of self.tableView.
Then you can tell if the method is getting called, if the if statement is evaluating as true, and if the table view is non-nil. One of those things is likely to be the cause of your problem.
I'm guessing that the if statement is wrong. what type is the property self.searchButtonTapped? Post the code that declares that property.
Based on the name I would guess that searchButtonTapped is a boolean?
you have declared only one IBAction, which is for the method searchButton.
This method call the searchSetup´s method. What is the purpose of it?
- (IBAction)searchButton:(id)sender {
[self searchSetup];
}
So you must have another IBAction for buttonTapped method witch is currently a "void" method and not a IBAction. Or you make that connection from the storyBoard, or you must declare it programaticly like:
[self.searchButtonTapped addTarget:self action:#selector(buttonTapped:) forControlEvents:UIControlEventTouchUpInside]
I'm stumped at why this code isn't working. I have a login button that I want to disable when the user isn't logged in.
I have a UIButton delared in my .h file like so:
IBOutlet UIButton *myBtn;
I've set up a referencing outlet in Interface Builder to this button.
In my .m file, I've tried:
[myBtn setEnabled: NO];
and
myBtn.enabled = NO;
But neither of these disable the button in the conditional statement I'm in. (I want to disable the login button when the user successfully logs in)
I'm able to do this with two other buttons on the same screen, so I know the code is correct. I don't throw any errors, so I think the object exists. The references to myBtn change color in XCode, too, so it appears to be a valid reference.
I must be missing something. What am I doing wrong here? (I'm a Windows developer, relatively new at Objective-C)
It seems ok to me. Are you synthesizing the button? Try
self.myBtn.enabled = NO;
If you're looking for Swift3 solution
var myBtn = UIButton()
myBtn.isEnabled = true
You should be setting up your button as a IBOutlet.
#property (weak, nonatomic) IBOutlet UIButton *myBtn;
That way you can connect that button in storyboards. Which could be your issue.
Then call this to disable.
[_myBtn setEnabled:NO];
Do try this ..
In .h :
#property(nonatomic,retain)UIButton *myBtn;
In .m :
#synthesize myBtn;
And then,replace your [myBtn setEnabled: NO]; code with [self.myBtn setEnabled: NO]; code.
If you are looking for swift code:
var button = UIButton()
button.enabled = false //disable the button
I've just started with xcode and objective-c and did some very basic apps, but what i'm having problem with is very basic this. the keyboard return button not hiding the keyboard.
I've searched the internet for the solution and all they say is to connect delegate to the file's owner and add the function and it should work, i did that and nothing is working.
I have an ok button and it is working and also clicking on any free space on the screen is working, just the return button....
I am using the simulator, not testing on iphone yet. (xcode 3.2.5 64 bit with the 4.2 simulator).
This is the line of code that should connect the delegate to every textFiled.
1. i've tried already to return both YES and NO, didn't work.
2. i've tried both a specific object name for the textField and this general way, didn't work.
- (BOOL)textFieldShouldReturn:(UITextField *)textField {
[textField resignFirstResponder];
return NO;
}
In the: basic view controller connection -> connections -> outlets, i have the: delegate -- File's Owner. and in the file's owner in referencing outlets there is: delegate - Round style text.....
EDIT - i forgot to mention before, i've check and the method isn't being called!!!
- (BOOL)textFieldShouldReturn:(UITextField *)textField{
NSLog(#"Working!!!");
[textField resignFirstResponder];
return YES;
}
what should i do to make it happen? that is why people say to connect the delegate, but in my case it is connected and not triggering the function...i know it is kind of dumb question but for a nobie like me the solution is not obvious...
OK, another Edit - with all my code: just can't understand what to do....
This is: basicViewController.h:
#import <UIKit/UIKit.h>
#interface basicViewController : <#superclass#> <UITextFieldDelegate>
#interface basicViewController : UIViewController <UITextFieldDelegate> {
//every object that we want to interact with (like text field or lable) is call an outlet!!!!
//here we define the outlets for our program
IBOutlet UITextField *txtName;
IBOutlet UILabel *lblMessage;
}
//here are the getters and setter for our outlets
#property (nonatomic, retain) IBOutlet UITextField *txtName;
#property (nonatomic, retain) IBOutlet UILabel *lblMessage;
//method decleration for the OK button action
- (IBAction) doSomething;
//method for hiding the keyboard when clicking on empty area in the app
//we will put an invisible button on all area and clicking on it will make keyboard disapear
- (IBAction) makeKeyboardGoAway;
#end
This is basicViewController.m:
#import "basicViewController.h"
#implementation basicViewController
//synthesizeing the objects that we made' this will create the getter and setters automaticly
#synthesize txtName;
#synthesize lblMessage;
- (IBAction) doSomething{
// makeing keyboard disapear when pressing ok button (doing that form the text field)
//when pressing the OK button, the keyboard will disapear and when clicking in the text field it will show again
[txtName resignFirstResponder];
NSString *msg = [[NSString alloc] initWithFormat:#"Hello, %#",txtName.text];
//the objective-c way for setting the test in the text field
[lblMessage setText:msg];
//the regular object oriented way
//lblMessage.text = msg;
[msg release];
}
- (IBAction) makeKeyboardGoAway{
[txtName resignFirstResponder];
}
//when clicking the return button in the keybaord
- (BOOL)textFieldShouldReturn:(UITextField *)textField{
NSLog(#"Working!!!");
[textField resignFirstResponder];
return YES;
}
- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
- (void)viewDidUnload {
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (void)dealloc {
[super dealloc];
}
#end
Maybe now i am more clear, sorry i didn't do it before.
Any one has an idea what am i doing wrong? it should be pretty strait forward.....
EDIT - Adding an image of all the elements, i hope that will help to help me :-)
10x a lot for every one that is trying to help....i really like this framework, it is so great after c++ and java, python and many other...and i am working with a book, but it is for ios 3.1, maybe that is the problem.....
Firstly you should check if textFieldShouldReturn: is actually being called by adding an NSLog statement or breakpoint at the beginning of the method.
Once that's out of the way, try an manually declare that your view controller conforms to <UITextFieldDelegate> protocol in your interface file:
#interface YourClass : ... <UITextFieldDelegate>
Also declare a property & outlet for your UITextField, make the appropriate connections in IB and manually declare self as the UITextField delegate with:
self.yourUITextFieldObject.delegate = self;
Once that's done see if your method above is now being called and make sure you return YES.
Just write one line in the
-(BOOL)textFieldShouldReturn:(UITextField *)textField{
}
before return YES;
the final version will be as given below:
-(BOOL)textFieldShouldReturn:(UITextField *)textField{
[textField resignFirstResponder];
return YES;
}
-(void)textFieldDidEndEditing:(UITextField *)textField{
NSLog(#"%#",textField.text);
}
You need to assign the delegate of the textfields to your file owner. The textfields are sending the message, but doesn't have a delegate to respond to it.
Use the interface builder to do that.
You have to implement this method..
-(BOOL)textFieldShouldReturn:(UITextField *)textField
{
[textField resignFirstResponder];
return YES;
}
Like Rog said, don't forget to register the textfield to the delegate, you can do this manually as he said but in Storyboard you can just control drag from all of your textfields to the view controller and register the delegate (choose delegate). Only the textfields that are registered can make use of all those methods.
So this line is important:
self.yourUITextFieldObject.delegate = self;
Or even more easy these days is to just use the storyboard:
textfield is in a subview? in this case, make sure textfield have as delegate the FileOwner.
put a log at the
- (IBAction) makeKeyboardGoAway
function. I think its this method everytime anything is tapped on the screen. In that case, you will need to send the touch event to the text field. Not sure how this is done but that should do it.
Else try removing the which takes care of tap(click) all over the view and try to do what you are doing.
Most likely the problem is that your actual view controller in the running application is not a "basicViewController" but a UIViewController that does not implement the UITextFieldDelegate-protocol.
What you've done in the interface builder by selecting your class "basicViewController" as the FilesOwner is just declaring the FilesOwner-object in your running application to be of type basicViewController; the actual object is not instantiated by this declaration and in your case it is not in the xib / nib.
Some other part of your code actually instantiates a view controller object and loads the xib / nib file. At that place, I guess your code is instantiating a UIViewController (typically by auto-generated code) and not an instance of your basicViewController; you simply have to change the class there.
Furthermore, this error often happens when using a UINavigationController or UITabBarController in the Interface Builder that is (should be) configured to instantiate and load other custom views. If you use such a higher-level controller, double-check that it is actually configured to use your basicViewController, not UIViewController when loading your view from the xib / nib.
Hope, that solves the issue!
Can you try this..
#interface ClassName : SuperClass < UITextFieldDelegate >
Use like this...
textfield.delegate=self;
and use the UITextFieldDelegate in .h class
You can always dismiss the keyboard when you don’t even know which view the text field is in by using:
Objective-C:
[[UIApplication sharedApplication] sendAction:#selector(resignFirstResponder)
to:nil
from:nil
forEvent:nil];
Swift:
UIApplication.sharedApplication().sendAction("resignFirstResponder",
to:nil,
from:nil,
forEvent:nil)
I need to keep track of which text field is the firstResponder for my custom keyboard to work. In the code below, I have grossly oversimplified my program, but here is the gist of the problem:
#implementation SimplePickerViewController
#synthesize pickerKeyboard;
#synthesize textView;
#synthesize textView2;
#synthesize firstResponder;
-(void)viewDidLoad{
pickerKeyboard = [[PickerKeyboardViewController alloc] initWithNibName:#"PickerKeyboard" bundle:nil];
pickerKeyboard.delegate = self;
[self.textView setInputView:pickerKeyboard.view];
[self.textView setDelegate:self];
[self.textView2 setInputView:pickerKeyboard.view];
[self.textView2 setDelegate:self];
}
-(void)hideKeyboard{
[self.firstResponder resignFirstResponder];
self.firstResponder = nil; //without this line, the code doesn't work.
}
- (BOOL)textViewShouldBeginEditing:(UITextView *)textView{
self.firstResponder = textView;
[self.pickerKeyboard.picker reloadAllComponents];
return YES;
}
If I remove the line setting the firstResponder to nil, the code ceases to function properly, but I am not sure why. (Without that line, I can select the first textView to bring up the keyboard, but after that I can never bring the keyboard back. Any ideas? Thanks!
I'm not sure that I understand why firstResponder needs to be kept track of for a custom keyboard to work. I use a custom keyboard without knowing what the first responder is.
Do you use:
textView.inputView = pickerKeyboard
How about the following, called on the view to resign the first responder:
[self.view endEditing:NO];
I have had a similar problem and I have just figured out the issue. Somewhere in some part of Apple's first responder code, they are using a selector named firstResponder. When you created the property firstResponder you inadvertently overrode that selector. That will cause Apple's code to fail. This, in my humble opinion, is a bug in Apple's framework, and the firstResponder method isn't documented anywhere. Name your property myFirstResponder or anything else and everything should work just fine.
See Why does the keyboard not show when a view is popped from the navigation stack?