C function calling objective C functions

Question

I\'ve a c function in my viewController.m.

int abc(int a, char* b)
{
//do something
}

I also have a function

-(void) call         


        

Answer 1

Your button doesn't show because of what others and myself were saying: you need the existing instance of the ViewController. You are creating an entirely new instance of the ViewController, which is never brought on screen or pushed, etc.

You can accomplish what you need to do by using a global variable that points to your existing instance.

Here's what your .m should look like:

#import "ViewController.h"

static ViewController *viewController = nil;

@implementation ViewController

- (id)init {
    if ((self = [super init])) {
         viewController = self;
    }
    return self;
}

- (void)dealloc {
    viewController = nil;
}

-(void) callIncomingCreateButton {
    UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    //set the position of the button
    button.frame = CGRectMake(100, 170, 100, 30);
    //set the button's title
    [button setTitle:@"Click Me!" forState:UIControlStateNormal];
    //add the button to the view
    [self.view addSubview:button];
}

- (IBAction)DemoCall:(id)sender {
    callIncoming(1, "a");
}

@end

int callIncoming(int a, char* b) {
    [viewController callIncomingCreateButton];
    return a;
}