自定义Navigationbar，使用Catagory

最新推荐文章于 2021-02-25 19:53:38 发布

转载最新推荐文章于 2021-02-25 19:53:38 发布 · 616 阅读

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本文介绍两种自定义iOS应用中NavigationBar的方法，一种是通过Category添加背景图片和自定义按钮，另一种是在UINavigationBar中直接绘制背景图片。

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自定义Navigationbar，使用Catagory

方法一：

// UINavBar.h
#import
@interface UINavigationBar (UINavigationBarCategory)
UIImageView *bg;
-(void)setBackgroundImage:(UIImage*)image;
- (void)insertSubview:(UIView *)view atIndex:(NSInteger)index;
@end
// UINavBar.m
#import “UINavBar.h”
@implementation UINavigationBar (UINavigationBarCategory)
-(void)setBackgroundImage:(UIImage*)image {
if(image == nil) return;
bg = [[UIImageView alloc]initWithImage:image];
bg.frame = CGRectMake(0.f, 0.f, self.frame.size.width, self.frame.size.height);
[self addSubview:bg];
[self sendSubviewToBack:bg];
[bg release];
}
- (void)insertSubview:(UIView *)view atIndex:(NSInteger)index
{
[super insertSubview:view atIndex:index];
[self sendSubviewToBack:bg];
}
@end
View Controller:
// MyViewController.m
- (void)viewDidLoad {
[super viewDidLoad];
[[self.navigationController navigationBar] setBackgroundImage:[UIImage imageNamed:@"navbar.png"]];
}
返回按钮：
- (void)viewDidLoad {
[super viewDidLoad];
UIButton *backButton = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 63, 30)];
[backButton setImage:[UIImage imageNamed:@"back.png"] forState:UIControlStateNormal];
[backButton addTarget:self action:@selector(pushBack) forControlEvents:UIControlEventTouchUpInside];
UIBarButtonItem *backButtonItem = [[UIBarButtonItem alloc] initWithCustomView:backButton];
self.navigationItem.leftBarButtonItem = backButtonItem;
[backButtonItem release];
[backButton release];
}

方法二：

http://discussions.apple.com/thread.jspa?threadID=1649012&tstart=0

方法一的问题在于当进入另外一个navicontroller后，回来时，原来navigationbar上的buttonitem就会不见，这猜测是层次的问题，后来见了一个老外的用的方法，无比简单，不过受到限制，只是已经足够用了
@implementation UINavigationBar (CustomImage)
- (void)drawRect:(CGRect)rect {
UIImage *image = [UIImage imageNamed: @"NavigationBar.png"];
[image drawInRect:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];
}
@end