How to set target and action for UIBarButtonItem at runtime

问题

Tried this but only works for UIButton:

[btn setTarget:self action:@selector(btnClicked:) forControlEvents:UIControlEventTouchUpInside];

回答1:

Just set the UIBarButtonItem's target and action properties directly.

回答2:

UIBarButtonItem doesnt have the same addTarget method so you have to set them directly as follows

btn.target = self;
btn.action = @selector(barButtonCustomPressed:);

...

// can specify UIBarButtonItem instead of id for this case
-(IBAction)barButtonCustomPressed:(UIBarButtonItem*)btn 
{
    NSLog(@"button tapped %@", btn.title);
}

回答3:

I ran into a similar problem... I assume you mean that if your UIButton is not part of your UITabBar to call btnClicked then it works appropriately. If this is the problem you are proposing then, check your btnClicked method and change it from:

-btnClicked:(id)sender

-(void) btnClicked:(id)sender

that, and declare btnClicked in the header file...

For what it's worth, this is how I setup a button in tabbarbuttonitem:

UIBarButtonItem *exampleButton = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"button.png"] style:UIBarButtonItemStylePlain target:self action:@selector(btnClicked:)];

回答4:

Set target and action of your UIBarButtonItem

Swift 5 & 4

button.target = self
button.action = #selector(action)

@objc func action (sender:UIButton) {
    print("action")
}

回答5:

If you need this enough times in your code, it's nice to go ahead and extend UIBarButtonItem which I've done below in Swift. :)

import UIKit

extension UIBarButtonItem {
    func addTargetForAction(target: AnyObject, action: Selector) {
        self.target = target
        self.action = action
    }
}

As an example, with self as a UIViewController, you'd simply call:

self.myBarButtonItem.addTargetForAction(self, action: #selector(buttonPressed(_:))

回答6:

  UIBarButtonItem *barListBtn = [[UIBarButtonItem alloc] initWithBarButtonSystemItem: UIBarButtonSystemItemAdd target:self action:@selector(getTruckStopListAction)];   
    self.navigationItem.rightBarButtonItem = barListBtn;
    [barListBtn release];

回答7:

@wp42 It does work today.

A nifty way of doing this in objective-C is adding a category to UIBarButtonItem class:

.h file

#import <UIKit/UIKit.h>

@interface UIBarButtonItem (addons)

-(void)addTarget:(id)target andAction:(SEL)action;

@end

.m file

#import "UIBarButtonItem+addons.h"

@implementation UIBarButtonItem (addons)

-(void)addTarget:(id)target andAction:(SEL)action{
   [self setTarget:target];
   [self setAction:action];
}

@end

In practice:

[myBtn addTarget:self andAction:@selector(myFunction:)];

回答8:

If you are programmatically adding the UIBarButtonItem, the best way to set the target and action is to initialize the button with one of the following methods:

UIBarButtonItem *customButton = [[UIBarButtonItem alloc] initWithImage:<#(UIImage)#> style:<#(UIBarButtonItemStyle)#> target:<#(id)#> action:<#(SEL)#>

UIBarButtonItem *customButton = [UIBarButtonItem alloc] initWithTitle:<#(NSString *)#> style:<#(UIBarButtonItemStyle)#> target:<#(id)#> action:<#(SEL)#>

UIBarButtonItem *customButton = [UIBarButtonItem alloc] initWithImage:<#(UIImage *)#> landscapeImagePhone:<#(UIImage *)#> style:<#(UIBarButtonItemStyle)#> target:<#(id)#> action:<#(SEL)#>

回答9:

Swift 5:

Extract to extensions:

extension UIBarButtonItem {

    static func nextBtn(target: AnyObject, action: Selector) -> UIBarButtonItem {
        let title = "Next"
        return button(title: title, target: target, action: action)
    }

    private static func button(title: String, target: AnyObject, action: Selector) -> UIBarButtonItem {
        return UIBarButtonItem(title: title, style: .done, target: target, action: action)
    }

}

Call in code:

navigationItem.rightBarButtonItem = .nextBtn(target: self, action: #selector(rightBarButtonAction))

Action:

@objc func rightBarButtonAction() {
    Swift.print("Button tapped!")
}

Pretty easy to add new buttons to this factory.

回答10:

You may want to try out the addTarget method.

来源：https://stackoverflow.com/questions/2333638/how-to-set-target-and-action-for-uibarbuttonitem-at-runtime

标签

ios

objective-c

iphone

swift

uibarbuttonitem