IOS Adding subview from other class programatically

Question

i've tried to create a custom view which works like a bottom bar and it worked

Right now this function is required on multiple classes, so i try writing it into a new class and import it which likes:

//BottomBarLauncher.h
#import <UIKit/UIKit.h>

@interface bottomBarLauncher : UIViewController
-(void)launchBottomBar;
@end

And implement it as :

//BottomBarLauncher.m
-(void) launchBottomBar{
    for (UIView *subView in [topView subviews]) {
        [subView removeFromSuperview];
    }
    UIView *btnBarView = [[UIView alloc]initWithFrame:CGRectMake(0,     self.view.frame.size.height - 53.3, 320, 53.3)];
    btnBarView.backgroundColor = [UIColor redColor];
    [self.view addSubview:btnBarView];
}

Now here's the problem, while i try implement it on a new view like follows:

//NewView.m
#import "BottomBarProtocol.h"

@interface NewView()
{
    BottomBarLauncher *btnBar;
}
@end
//blahblahblah

[btnBar launchBottomBar];

and nothing happens, i think the problem was with

[self.view addSubview:btnBarView];

but i have no idea how to select the current view as target which i can add subview onto.

Answer 1

First a suggestion, looking at your requirements/code I think you want to create custom view. For creating a custom view, create a class which inherits from UIView rather than creating a UIViewController.

Now moving to the code, your btnBar is a UIViewController which has its own view self.view so when you call this [btnBar launchBottomBar] internally you are adding the bottom bar on self.view that is your btnBar controllers view and not on NewView controllers view. Hope you understand what I am pointing out.

Here you are missing out few calls,

btnBar.view.frame = CGRectMake(0,self.view.bounds.size.height-40,self.view.bounds.size.width,40); // Add suitable frame.

//This call will add the btnBar's view as subview onto your current view controller's view.
[self.view addSubView:btnBar.view];

This is not correct/recommended way and you can face serious challenges regarding memory leaks. To avoid those mistakes, as I suggested, create a custom UIView instead. Take a look around on how to create custom views.

Hope that helps!

Answer 2

You can return the UIView form launchBottomBar method and add as a subView in your current ViewController class

Answer 3

Make custom class and delegate and add that view in window and set its frame so that it is not visible and set its frame and slide from bottom when needed so you can use it in all view controller.
Thanks.