I got a very simple app. it gets slider value and display it on text box. The interface and implementation is as follow:
#import <Foundation/Foundation.h>
#interface HelloWorld : NSObject
#property (assign) IBOutlet NSTextField *Tf;
#property (assign) IBOutlet NSSliderCell *Sc;
#end
#import "HelloWorld.h"
#implementation HelloWorld
#synthesize Tf;
#synthesize Sc;
- (IBAction)Pressed:(id)sender {
[Tf setStringValue:#"Hey"];
}
- (IBAction)Scroll:(id)sender {
[Tf setStringValue: [Sc indexOfTickMarkAtPoint]];
}
#end
The UI:
Problem:
The app crashes when I move the slider.
indexOfTickMarkAtPoint returns NSInteger but setStringValue: wants (somewhat obviously) a string. Look at the documentation for NSString method stringWithFormat: for a description of how to do the conversion.
Something like:
[Tf setStringValue:[NSString stringWithFormat:#"%d", [Sc indexOfTickMarkAtPoint]]];
Whats happening is its an NSInteger and not a pointer to an Object
[Tf setIntegerValue:[Sc indexOfTickMarkAtPoint]];
Related
I would like to set an text in the text field in another class and get it from another class. This is something what I want, but it does not work. Can you please help me. Thank you!
aaa.h
#import <Cocoa/Cocoa.h>
#interface aaa : NSImageView {
IBOutlet NSTextField *message;
}
#property (nonatomic, retain) IBOutlet NSTextField *message;
#end
aaa.m
#import "aaa.h"
#import "bbb.h"
#implementation aaa
#synthesize message;
- (void)awakeFromNib {
// [message setStringValue:#"ok, this works!"]; //but i don't want it from here
[self hello];
}
#end
bbb.h
#import <Foundation/Foundation.h>
#interface NSObject (bbb)
- (void)hello;
#end
bbb.m
#import "bbb.h"
#import "aaa.h"
#implementation NSObject (bbb)
- (void)hello {
aaa *obj = [[[aaa alloc] init] autorelease];
[obj.message setStringValue:#"This doesn't work :("]; // set text here, dont work.
NSLog(#"TEST: %#", [obj.message stringValue]);
}
#end
You are using category, so first thing it is used for extending the functionality of existing class. So you cannot set textfield value inside category. But else you can add some functonality after extracting the value. So you have to pass the value inside the category first. Try like this below:
- (void)awakeFromNib {
NSString *resultString=[self hello:#"This doesn't work :("];
[message setStringValue:resultString];
}
#end
#interface NSObject (bbb)
- (NSString*)hello:(NSString*)yourString;
#end
#implementation NSObject (bbb)
- (NSString*)hello:(NSString*)yourString {
return yourString;
}
#end
I have a window with a large NSTextFeildCell, where text can be modified. Upon clicking a button another window appears where the text from the original window can be used some how. The issue I am having is when I attempt to retrieve that text the log spits out...
" -[NSTextView stringValue]: unrecognized selector sent to instance 0x100151860"
Fallowed by a long trace...
I have tried to solve this several different ways but with no luck.
currently,
First window controller
.h
#import <Cocoa/Cocoa.h>
#class NextWindowController;
#interface TextViewWindowController : NSWindowController
#property (nonatomic, weak) NextWindowController *NextWindow;
#property (nonatomic, weak) IBOutlet NSTextFieldCell *txtTextView;
- (IBAction)btnClicked:(id)sender;
- (NSString*)getText;
#end
.m
#import "TextViewWindowController.h"
#import "NextWindowController.h"
#implementation TextViewWindowController
#synthesize NextWindow;
- (IBAction)btnClicked:(id)sender{
[NextWindow setCallingWindow:self];
[NextWindow showWindow:self];
}
- (NSString*)getText{
return [_txtTextView stringValue];// there is a problem with the view...
}
#end
Next Window controller
.h
#import <Cocoa/Cocoa.h>
#class TextViewWindowController;
#interface NextWindowController : NSWindowController{
NSMutableString* str;
}
#property (nonatomic, weak) TextViewWindowController *callingWindow;
#end
.m
#import "NextWindowController.h"
#import "TextViewWindowController.h"
#implementation NextWindowController
#synthesize callingWindow;
- (IBAction)btnEnterClicked:(id)sender{
[str setString:callingWindow.txtTextView.stringValue];
}
- (id)initWithWindow:(NSWindow *)window{
self = [super initWithWindow:window];
if (self) {
str = [[NSMutableString alloc] init];
}
return self;
}
#end
I have also tried str = [callingWindow getText] with the same result.
Any help would be very appreciated!
It's not super intuitive to figure out from Apple's documentation, but to get the raw string value of a NSTextView (which inherits from NSText), just use:
[_txtTextView string];
And since you're using properties, it might be smarter to use the accessor in your function, like this:
- (NSString*)getText{
return [self.txtTextView string];
}
I recently started learning Objective-C and Cocos-2D. I tried to define my own method for automating the creation of sprites.
I added my own class where I'll create other automation methods as well. Anyhow my .h file looks like this:
#import <Foundation/Foundation.h>
#import "cocos2d.h"
#interface ActionsClass : CCNode {
}
#property (nonatomic, strong) CCSprite* createSprite;
#property (nonatomic, strong) CCSprite* spriteName;
#property (nonatomic, strong) NSString* pngName;
#property (nonatomic) CGPoint* spriteCoordinate;
- (CCSprite *)createSprite: (CCSprite *)spriteName: (NSString *)pngName: (CGPoint *)spriteCoordinate;
#end
And the .m is:
#import "ActionsClass.h"
#implementation ActionsClass
#synthesize createSprite = _createSprite;
#synthesize spriteName = _spriteName;
#synthesize pngName = _pngName;
#synthesize spriteCoordinate = _spriteCoordinate;
- (CCSprite *)createSprite: (CCSprite *)spriteName: (NSString *)pngName: (CGPoint *)spriteCoordinate
{
if (!_createSprite)
{
_createSprite = [[CCSprite alloc] init];
_spriteName = [CCSprite spriteWithFile:_pngName];
_spriteName.position = ccp(_spriteCoordinate->x, _spriteCoordinate->y);
[self addChild:_spriteName];
}
return _createSprite;
}
#end
In the main .m file where I want to call the method:
[self createSprite: saif: #"saif.png": ccp(100,100)];
This would give the warning that xcode didn't find the instance method createSprite and defaults it to id
Thanks a lot and sorry if the font or the formatting of the question aren't super neat.
Your method declaration is wrong, so you wont be able to call it.
It should be:
- (CCSprite *)createSprite:(CCSprite *)spriteName pngName:(NSString *)pngName coord:(CGPoint *)spriteCoordinate;
And called like:
[self createSprite:someSprite pngName:somePNGName coord:someCoord];
Edit: I didn't see that you were trying to call this from another class. To do that you will need to import the ActionsClass header file, and call this method on an instance of ActionsClass, e.g.
ActionsClass *actionsClassObject = [[ActionsClass alloc] init];
[actionsClassObject createSprite:someSprite pngName:somePNGName coord:someCoord];
Right before my model class sends the variable stringToDisplay, NSLog shows me that it has a value. But when I try to use it in my ViewController, I just get (null). Any thoughts about what I'm doing wrong?
(The good news is that, while working on this, I had sort of a breakthrough in understanding how models and controllers relate to each other. I'm still a complete newbie, but I don't feel quite as lost as I did.)
Here's what I think is the relevant code:
CalculatorBrain.h
#import <Foundation/Foundation.h>
#interface CalculatorBrain : NSObject
#property (nonatomic) NSMutableString *stringToAdd;
#property (nonatomic,strong) NSString *stringForDisplay;
- (double)performOperation:(NSString *)operation withArray:(NSMutableArray *)particularStackYouNeedToPopOff;
CalculatorBrain.m
#implementation CalculatorBrain
#synthesize stringToAdd = _stringToAdd;
#synthesize stringForDisplay = _stringForDisplay;
#synthesize whatHappenedSinceLastClear = _whatHappenedSinceLastClear;
- (double)performOperation:(NSString *)operation withArray:(NSMutableArray *)particularStackYouNeedToPopOff
{
<long code that I think doesn't matter because this NSLog produces exactly what I want it to:>
NSLog(#"%#",stringForDisplay);
return result;
}
CalculatorViewController.h
#import <UIKit/UIKit.h>
#interface CalculatorViewController : UIViewController
#property (nonatomic) NSArray *arrayOfDictionaries;
#property (nonatomic) NSDictionary *dictionary;
#property (weak, nonatomic) IBOutlet UILabel *variablesUsed;
#property (nonatomic, strong) NSString *operation;
#end
CalculatorViewController.m
#import "CalculatorViewController.h"
#import "CalculatorBrain.h"
#interface CalculatorViewController ()
#property (nonatomic,strong) CalculatorBrain *brain;
#end
#implementation CalculatorViewController
#synthesize display = _display;
#synthesize history = _history;
#synthesize brain = _brain;
#synthesize operation = _operation;
- (IBAction)operationPressed:(UIButton *)sender
{
NSString *otherString=[self.brain stringForDisplay];
if (self.userIsEnteringNumber) [self enterPressed];
NSString *operation = sender.currentTitle;
double result = [self.brain performOperation:operation withArray:[self.brain whatHappenedSinceLastClear]];
self.display.text = [NSString stringWithFormat:#"%g",result];
self.history.text = otherString;
NSLog(#"%#",otherString);
}
And the NSLog in that last line of code give me (null).
Any thoughts?
Maybe I'm missing something but your property is declared in the class extension of CalculatorBrain so nobody outside CalculatorBrain.m knows about this property.
So if you want to expose this property to other objects, you will have to declare it in CalculatorBrain.h instead.
Oh - your declaration of the property whatHappenedSinceLastClear isn't exposed to other classes that import CalculatorBrain.h because you put the property declaration in an interface extension in the .m file, which other classes will not see.
To make it publicly accessible move the #property line for whatHappenedSinceLastClear to CalculatorBrain.h, not the .m file.
I can guess that problem lies in the way you assign your stringForDisplay, eg.:
if you use something like
stringForDisplay_ = anotherString;
setter for property doesn't fire, so you have to retain your variable yourself otherwise it'll live just until your method finishes;
If so - use property setters, eg.:
self.stringForDisplay = anotherString;
that way ARC will do all the memory management.
It really depends how you set stringForDisplay inside the performOperation:withArray: method.
for a blind guess, try using
NSString *otherString = self.brain.stringForDisplay;
after this line
double result = [self.brain performOperation:operation withArray:[self.brain whatHappenedSinceLastClear]];
I am trying to make a practice application that takes two entered words (word1, word2) and puts them together to make a compound word. I am very new to this and would like to know the correct way to display these two variables under the action "buttonPressed."
Here's the header file...
#import <UIKit/UIKit.h>
#interface Word_CombinerViewController : UIViewController {
UITextField *word1;
UITextField *word2;
UITextField *display;
UIButton *mashButton;
}
#property (nonatomic, retain) IBOutlet UITextField *word1;
#property (nonatomic, retain) IBOutlet UITextField *word2;
#property (nonatomic, retain) IBOutlet UITextField *display;
#property (nonatomic, retain) IBOutlet UIButton *mashButton;
-(IBAction)textFieldDoneEditing:(id)sender;
-(IBAction)backgroundTap:(id)sender;
-(IBAction)buttonPressed:(id)sender;
#end
And here's the implementation file (.m)...
#import "Word_CombinerViewController.h"
#implementation Word_CombinerViewController
#synthesize word1;
#synthesize word2;
#synthesize display;
#synthesize mashButton;
-(IBAction)textFieldDoneEditing:(id)sender {
[sender resignFirstResponder];
}
-(IBAction)backgroundTap:(id)sender {
[word1 resignFirstResponder];
[word2 resignFirstResponder];
}
-(IBAction)buttonPressed:(id)sender {
NSString *newText = [NSString: #word1, #word2]
display.text = newText;
[newText release]
}
- (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 {
[word1 release];
[word2 release];
[display release];
[mashButton release];
[super dealloc];
}
#end
I know this code is probably full of errors, but everyone has gotta start somewhere, right?
Any feedback would be greatly appreciated, thank you!
NSString *newText = [NSString: #word1, #word2]
This code doesn't make any sense. The first part of a message is the receiver, and it won't have any colons in it. The second part is the message itself, i.e. the method name along with any necessary parameters. What you're looking for is:
NSString *newText = [NSString stringWithFormat:#"%#%#", word1, word2];
The -stringWithFormat: method uses a format string (very much like printf()) and a variable number of parameters to fill in the placeholders in the format string.
Also, when you create a string (or any object) using a "convenience method" like this, you shouldn't release it. You didn't retain or alloc or copy it, so it's not your responsibility to release it. You'll want to remove that line from your -buttonPressed method.
Try this:
-(IBAction)buttonPressed:(id)sender {
NSString *newText = [word1.text stringByAppendingString:word2.text]
display.text = newText;
}