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This article mainly introduces iOS how to customize UIBarButtonItem target and action, has a certain reference value, interested friends can refer to, I hope you can learn a lot after reading this article, the following let Xiaobian take you to understand.

Requirements description:

In the process of project development, you need to customize the UIBarButtonItem to achieve the sharing style, and pop up the system sharing box (UIActivityViewController) in the iPad, and the system sharing box needs to specify the display location (barButtonItem). The custom UIBarButtonItem target points to UIButton. This is not in line with the requirements, you need to customize the UIBarButtonItem.

Before introducing the custom UIBarButtonItem, let's introduce the child parent relationship (or inheritance relationship) of the relevant controls.

1 、 UIBarItem

NS_CLASS_AVAILABLE_IOS (2: 0) @ interface UIBarItem: NSObject

2 、 UIBarButtonItem

NS_CLASS_AVAILABLE_IOS (2: 0) @ interface UIBarButtonItem: UIBarItem

3 、 UITabBarItem

NS_CLASS_AVAILABLE_IOS (2: 0) @ interface UITabBarItem: UIBarItem

UIBarButtonItem has three effects to display, which are

1. The return button on the left side of the navigation, the backBarButtonItem attribute in UINavigationItem

@ property (nullable,nonatomic,strong) UIBarButtonItem * backBarButtonItem

2. Plain text UIBarButtonItem

-(instancetype) initWithTitle: (nullable NSString *) title style: (UIBarButtonItemStyle) style target: (nullable id) target action: (nullable SEL) action

3. UIBarButtonItem of pure images, including custom images and system styles

-(instancetype) initWithImage: (nullable UIImage *) image style: (UIBarButtonItemStyle) style target: (nullable id) target action: (nullable SEL) action

-(instancetype) initWithBarButtonSystemItem: (UIBarButtonSystemItem) systemItem target: (nullable id) target action: (nullable SEL) action

UIToolBar's use of UIBarButtonItem is consistent with navigation.

There is not much introduction to UITabBarItem here, but its display effect is compared with UIBarButtonItem.

During the development process, we will use custom UIBarButtonItem to show the interface effect we want. The methods often used are:

-(instancetype) initWithCustomView: (UIView *) customView

-(void) viewDidLoad {[super viewDidLoad]; / / Custom View UIView * view = [[UIView alloc] initWithFrame:CGRectMake (0.0,0.0,60.0,40.0)]; view.backgroundColor = [UIColor redColor]; / / Custom button UIButton * btn = [UIButton buttonWithType:UIButtonTypeCustom]; btn.frame = view.bounds; [btn addTarget:self action:@selector (clickRight:) forControlEvents:UIControlEventTouchUpInside]; [view addSubview:btn] / / Custom Item UIBarButtonItem * barItem = [[UIBarButtonItem alloc] initWithCustomView:view]; / / self.navigationItem.leftBarButtonItem = barItem;} # pragma mark-(void) clickRight: (id) sender {NSLog (@ "sender:%@", sender);}

Where sender is printed, and its type is UIButton.

2017-10-17 16 TestImage 08V 43.917 TestImage [5482 RS 163865] sender:

Through the above description, it is found that the system method can not achieve the effect of project requirements. Of course, the requirement effect can also be achieved through the property saving UIBarButtonItem method. That is, after clicking the button to respond, directly use the saved UIBarButtonItem, but I did not use this method.

Here are two solutions I've given:

Option one

Inherit UIBarButtonItem and implement subclasses.

Define subclass

# import @ interface LLBarButtonItem: UIBarButtonItem@end

# import "LLBarButtonItem.h" @ implementation LLBarButtonItem- (id) initWithCustomView: (UIView *) customView {self = [super initWithCustomView:customView]; if (self) {UIButton * btn = [UIButton buttonWithType:UIButtonTypeCustom]; btn.frame = customView.bounds; btn.backgroundColor = [UIColor clearColor]; [btn addTarget:self action:@selector (clickButton:) forControlEvents:UIControlEventTouchUpInside]; [customView addSubview:btn];} return self }-(void) clickButton: (UIButton *) sender {if (self.target & & [self.target respondsToSelector:self.action]) {/ / [self.target performSelector:self.action withObject:self]; IMP imp = [self.target methodForSelector:self.action]; void (* func) (id, SEL, id) = (void *) imp; func (self.target, self.action, self);}} @ end

Define subclass objects and call subclass objects

-(void) viewDidLoad {[super viewDidLoad]; / Custom View UIView * view = [[UIView alloc] initWithFrame:CGRectMake (0.0,0.0,60.0,40.0)]; view.backgroundColor = [UIColor clearColor]; / / Custom Item LLBarButtonItem * barItem = [[LLBarButtonItem alloc] initWithCustomView:view]; barItem.target = self; barItem.action = @ selector (clickRight:); / / self.navigationItem.leftBarButtonItem = barItem } # pragma mark-(void) clickRight: (id) sender {NSLog (@ "sender:%@", sender);}

Print target object

2017-10-17 16-24-24-11. 696 TestImage [5557-170144] sender:

Option 2

UIBarButtonItem category

Define Category

# import @ interface UIBarButtonItem (Custom)-(void) addCutomTarget: (id) target action: (SEL) action;@end

# import "UIBarButtonItem+Custom.h" @ implementation UIBarButtonItem (Custom)-(void) addCutomTarget: (id) target action: (SEL) action {if (self.customView! = nil) {self.target = target; self.action = action; / / UIButton * btn = [UIButton buttonWithType:UIButtonTypeCustom]; btn.frame = self.customView.bounds; btn.backgroundColor = [UIColor clearColor]; [btn addTarget:self action:@selector (clickButton:) forControlEvents:UIControlEventTouchUpInside]; [self.customView addSubview:btn] }}-(void) clickButton: (UIButton *) sender {if (self.target & & [self.target respondsToSelector:self.action]) {/ / [self.target performSelector:self.action withObject:self]; IMP imp = [self.target methodForSelector:self.action]; void (* func) (id, SEL, id) = (void *) imp; func (self.target, self.action, self);}} @ end

Call the category method

-(void) viewDidLoad {[super viewDidLoad]; / Custom View UIView * view = [[UIView alloc] initWithFrame:CGRectMake (0.0,0.0,60.0,40.0)]; view.backgroundColor = [UIColor clearColor]; / / Custom Item UIBarButtonItem * barItem = [[UIBarButtonItem alloc] initWithCustomView:view]; [barItem addCutomTarget:self action:@selector (clickRight:)]; / / self.navigationItem.leftBarButtonItem = barItem } # pragma mark-(void) clickRight: (id) sender {NSLog (@ "sender:%@", sender);}

Print target object

2017-10-17 16 2814. 407 TestImage [5598 Rd 172418] sender:

Thank you for reading this article carefully. I hope the article "how to customize the target and action of UIBarButtonItem by iOS" shared by the editor will be helpful to everyone. At the same time, I also hope that you will support and follow the industry information channel. More related knowledge is waiting for you to learn!

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