统一设置UINavigationController左上角图标

方法一

通过工厂方法,然后在需要左上角显示图标的ViewController的viewDidLoad方法调用。代码如下:

==Factory.h文件==

1
2
3
4
5
#import <Foundation/Foundation.h>

@interface Factory : NSObject
+ (void)addBackButton:(UIViewController *)viewController;
@end

==Factory.m文件==

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
#import "Factory.h"

@implementation Factory
+ (void)addBackButton:(UIViewController *)viewController{
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setImage:[UIImage imageNamed:@"community_highlight"] forState:UIControlStateNormal];
[button setImage:[UIImage imageNamed:@"community_highlight"] forState:UIControlStateHighlighted];
CGRect frame = button.frame;
frame.size = button.currentImage.size;
button.frame = frame;
UIBarButtonItem *buttonItem = [[UIBarButtonItem alloc]initWithCustomView:button];
UIBarButtonItem *speaceItem = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace target:nil action:nil];
speaceItem.width = -5;
viewController.navigationItem.leftBarButtonItems = @[speaceItem,buttonItem];
}
@end

方法二

这种方法是通过实现UINavigationController的pushViewController方法,拦截所有push进来的viewController,然后对其进行设置。代码如下:

==BaseNavigationController.h文件==

1
2
3
4
5
#import <UIKit/UIKit.h>

@interface BaseNavigationController : UINavigationController

@end

==BaseNavigationController.m文件==

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
#import "BaseNavigationController.h"

@interface BaseNavigationController ()

@end

@implementation BaseNavigationController

- (void)addBackButton:(UIViewController *)viewController{
if (self.viewControllers.count > 0) {
viewController.hidesBottomBarWhenPushed = YES;

UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setImage:[UIImage imageNamed:@"back_icon_red"] forState:UIControlStateNormal];
[button setImage:[UIImage imageNamed:@"back_icon_red"] forState:UIControlStateHighlighted];
[button addTarget:self action:@selector(back) forControlEvents:UIControlEventTouchUpInside];
button.size = button.currentImage.size;
UIBarButtonItem *buttonItem = [[UIBarButtonItem alloc]initWithCustomView:button];
UIBarButtonItem *speaceItem = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace target:nil action:nil];
speaceItem.width = -5;
viewController.navigationItem.leftBarButtonItems = @[speaceItem,buttonItem];
}
}

- (void)back{
[self popViewControllerAnimated:YES];
}

- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated{
NSLog(@"push");
[self addBackButton:viewController];
[super pushViewController:viewController animated:animated];
}

#pragma -mark 生命周期
- (void)viewDidLoad {
[super viewDidLoad];
}

- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
}
@end

注意:

  1. 用方法一如果某个viewController需要单独设置navigationItem的图标,则在ViewController的viewDidLoad方法里设置即可。
  2. 用了方法二如果在push之前调用设置view样式有关的方法,则先调用viewDidLoad方法,然后调用push方法。这时如果在viewDidLoad方法里设置navigationItem的图标将跟push方法拦截viewController设置的效果一样。

所谓的拦截,大部分都是通过自定义类,然后重写自带方法实现的。

–EOF–