How do I set outlets'/text field's string value during runtime?

[cloud1]

How do I set outlets's or text fields' string value using setStringValue during runtime with out an event been triggered?

 

What I meant by "with out an event been triggered" is with out the user interaction with the GUI, like doesn't require an user to click on a button or etc.

 

For example:

 

//DisplayController.h
#import <Cocoa/Cocoa.h>

@interface DisplayController : NSObject 
{
IBOutlet NSTextField *textFieldDisplay;
}
- (IBAction)changeTextFieldText:(id)sender;
-(IBAction) changeText:(NSString*) text;
@end

 

// DisplayController.m
#import "DisplayController.h"

@implementation DisplayController
- (IBAction)changeTextFieldText:(id)sender
{
[textFieldDisplay setStringValue:@"This is a text field!"];
}

-(IBAction) changeText: (NSString *) message
{
textFieldDisplay=[[NSTextField alloc] init];
[textFieldDisplay setStringValue:message];
}

@end

 

//main.m

#import <Cocoa/Cocoa.h>
#import <stdio.h>
#import "DisplayController.h"

int main(int argc, char *argv[])
{
DisplayController *dc;
dc=[[DisplayController alloc] init];
[dc changeText:@"This is a text field!"]; /*This doesn't work because it doesn't change the text field's string value*/
[dc release];
return NSApplicationMain(argc,  (const char **) argv);
}

[stroke]

Well, there are some issues with your code. This version, through just modifying DisplayController.m would work:

#import "DisplayController.h"

@implementation DisplayController
-(void)awakeFromNib						  // awakeFromNib is automatically called when the object (DisplayController) is instantiated by the NIB file — no need to modify main.m
{
[self changeText:@"string"];
}
- (IBAction)changeTextFieldText:(id)sender
{
[textFieldDisplay setStringValue:@"This is a text field!"];
}

-(IBAction) changeText: (NSString *) message
{
[textFieldDisplay setStringValue:message];
}

@end

 

textFieldDisplay is an IBOutlet — it should be hooked up to an NSTextField in your XIB/NIB file. Also, you need to make sure that you made an instance of DisplayController in your XIB/NIB.

[cloud1]

I had been busy lately, but I have tried the code that you gave me and it still doesn't work. Anyway I don't know what is wrong with the code that you gave me and my before source code and after source code, and I also follow all the instructions that you told me to follow and it still doesn't work. But thanks anyway for trying to help me.

[stroke]

Did you properly connect the outlets?

[cloud1]

Yes, I have had properly connected the outlets.

[stroke]

Well, I don't know what you're doing wrong. Assuming you want the string to change as soon as the program starts, the code I used above works fine for me. You can see this with the project I've attached...

Field.zip

[cloud1]

Well, I don't know what you're doing wrong. Assuming you want the string to change as soon as the program starts, the code I used above works fine for me. You can see this with the project I've attached...

 

Sorry for the late reply again because I'm very busy. The source codes/project file that you have attached also works for me too. But my intention is based on the current design/set up I wanted the text field string value to change while the program is running and it doesn't require user interaction(s), system event(s), etc.

 

For example:

 

//main.m

#import <Cocoa/Cocoa.h>
#import <stdio.h>
#import "DisplayController.h"

int main(int argc, char *argv[])
{
DisplayController *dc;
int counter=0;

dc=[[DisplayController alloc] init];

while (counter<100)
{
  counter++;
  [dc changeText:@""+counter];/*This doesn't work because it doesn't change the text field's string value*/
}

[dc release];
return NSApplicationMain(argc,  (const char **) argv);
}

[stroke]

main.m is not a class. You can not give it outlets.

 

What you want is an NSTimer, look in the documentation. You need to make an AppController class, or somesuch.

[cloud1]

main.m is not a class. You can not give it outlets.

 

What you want is an NSTimer, look in the documentation. You need to make an AppController class, or somesuch.

 

I have tried your suggestion and many other possibilities, but it still doesn't work.

 

The following attachment is my XCode project.

Cocoa_Application.zip

[alloutmacstoday]

Just get rid of the stuff in main.m that you added.

[cloud1]

Just get rid of the stuff in main.m that you added.

 

[dc changeText1:@"This is a text field!!!!!!!"];

 

 

The above code and the rest of the codes in main.m doesn't produce compiler time errors or runtime errors,

but just that it doesn't change the text filed string value when they got executed.

How can I made this work based on my current design?

Cocoa_Application.zip

[alloutmacstoday]

I know that it doesn't produce them

 

If you do get rid of them though, it will work.

 

The issue is you have two instances of displayController. 1)the once created when the nib loads. and 2) the one you create in main.m. The one created in main.m will not work, because it is loaded first.

[cloud1]

I know that it doesn't produce them

 

If you do get rid of them though, it will work.

 

The issue is you have two instances of displayController. 1)the once created when the nib loads. and 2) the one you create in main.m. The one created in main.m will not work, because it is loaded first.

 

Oh, okay, so it will not work. I get it.

 

Anyway, then, how can I can access IBOutlet textField from main.m?

 

And, what access modifier(s) do I have to specified in front of some variables in some other files/classes so that I can access it from main.m?

 

I have to use the "extern" access modifier, right?

[alloutmacstoday]

why do you want to access them from main.m so badly?

[cloud1]

why do you want to access them from main.m so badly?

 

Because I came from a C++, Java, and etc programming background, and this is how the text field, label, and etc were accessed. In C++, and Java, and etc, the text field, label, and etc, can be access and it string value can be modified if only if the programmer provide access to it in some other classes or in the same class where the text field, label, etc, were defined and declared.

 

For example:

 

// Main.java
public class UserInterface extends JFrame
{
JTextField textField;

public UserInterface ()
{
	super();
	initialize();
}

  private void initialize ()
  {
  		int x=0;
	String result="";
	textField=new JTextField();

	while (x<=100)
	{
	   x+=1;
	   result+=x+", ";
   }
  TextField.setText(result);
  }
}

[alloutmacstoday]

Yeah, I came from java too, but you really just can't do it that way in objective-c. Sorry!

[cloud1]

Thanks for all your help.