UINavigationbar的背景修改方法集合

最近我突然發現UINavigationbar背景修改的方法不起作用了，代碼如下：

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@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

發現原來是iOS 5的原因，如果運行在iOS 5以下的版本就沒有問題了。經過實驗以下方法適合iOS 5（放在ViewDidLoad中）：

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if ([self.navigationController.navigationBar respondsToSelector:@selector( setBackgroundImage:forBarMetrics:)]){         [self.navigationController.navigationBar setBackgroundImage:[UIImage imageNamed:@"navigationbar.png"] forBarMetrics:UIBarMetricsDefault];     }

第一條if語句的作用是防止程式在iOS 5以下的版本中崩潰。

這樣，依靠這兩段代碼，我的UINavigationbar的背景問題在iOS 5及以下版本中得到了完美的解決。

 

 

iOS5之前是如何自訂UINavigationBar背景的？ 

在iOS5.0中我們可以非常簡單的設定UINavigationBar的背景（setBackgroundImage: forBarMetrics:方法），而這對於之前的版本是不可同日而語的。通過網路收集整理了一下以前的各種方式，只能作為學習筆記做個記錄，菜鳥學習而已。高人就跳過吧。
方法一：主要技巧就是用視圖的drawInRect:方法繪製
如下為建立了一個UINavigationBar Category

// 其實現代碼如下
@implementation UINavigationBar (UINavigationBarCategory)

- (void)drawRect:(CGRect)rect {
//顏色填充
     UIColor *color = [UIColor redColor];
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetFillColor(context,CGColorGetComponents([color CGColor]));
    CGContextFillRect(context,rect);
    self.tintColor = color;

//圖片填充
     UIColor *color = [UIColor colorWithRed:46.0f/255.0f green:87.0f/255.0f blue:29.0f/255.0f alpha:1.0f];
    UIImage *img = [UIImage imageNamed:@"bg.png"];
    [img drawInRect:CGRectMake(0,0,self.frame.size.width,self.frame.size.height)];
    self.tintColor = color;
}
@end

自訂圖片背景以下兩句代碼是關鍵：
UIImage *img = [UIImage imageNamed:@"bg.png"];

[img drawInRect:CGRectMake(0,0,self.frame.size.width,self.frame.size.height)];
或者：
UIImage *img = [UIImage imageNamed:@"bg.png"];
CGPoint point = {0,0};
[img drawAtPoint:point];
或者：

//加入旋轉座標系代碼

 

// Drawing code

 

UIImage *navBarImage = [UIImage imageNamed:@"LOGO_320×44.png"];

 

CGContextRef context = UIGraphicsGetCurrentContext();

 

CGContextTranslateCTM(context, 0.0, self.frame.size.height);

 

CGContextScaleCTM(context, 1.0, -1.0);

 

CGPoint center=self.center;

 

CGImageRef cgImage= CGImageCreateWithImageInRect(navBarImage.CGImage,CGRectMake(0, 0, 1, 44));

 

CGContextDrawImage(context, CGRectMake(center.x-160-80, 0, 80,self.frame.size.height), cgImage);

 

CGContextDrawImage(context, CGRectMake(center.x-160, 0, 320,self.frame.size.height), navBarImage.CGImage);

 

CGContextDrawImage(context, CGRectMake(center.x+160, 0, 80,self.frame.size.height), cgImage);
擴充UINavigationBar的drawRect方法的這種自訂方法會影響到工程項目中所有的導航條欄。
類似在iOS5.0中，由於UINavigationBar、UIToolBar和UITabBar的實現方式改變，而drawRect:方法不會被調用了，所以就不支援這種通過定義導航條類別的方式來自訂導航條了。除非在這類控制項的子類中實現。

//子類可以調用drawRect:方法
@interface MyNavigationBar : UINavigationBar
@end
@implementation MyNavigationBar
- (void)drawRect:(CGRect)rect {
　　[super drawRect:rect];
}
@end

方法二：定義UINavigationBar的一個static函數

 1 + (UINavigationBar *)createNavigationBarWithBackgroundImage:(UIImage *)backgroundImage title:(NSString *)title {
 2       UINavigationBar *customNavigationBar = [[[UINavigationBar alloc] initWithFrame:CGRectMake(0, 0, 320, 44)] autorelease];
 3       UIImageView *navigationBarBackgroundImageView = [[UIImageView alloc] initWithImage:backgroundImage];
 4       [customNavigationBar addSubview:navigationBarBackgroundImageView];
 5       UINavigationItem *navigationTitle = [[UINavigationItem alloc] initWithTitle:title];
 6       [customNavigationBar pushNavigationItem:navigationTitle animated:NO];
 7       [navigationTitle release];
 8       [navigationBarBackgroundImageView release];
 9       return customNavigationBar;
10 }

複製代碼

下面是在需要產生UINavgationBar 的地方添加的代碼     *ViewController.m：

View Code

 1 self.navigationController.navigationBar.hidden = YES;
 2 UIImage *navigationBarBackgroundImage =[UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"topbar-bg" ofType:@"png"]];
 3 UINavigationBar *customNavigationBar = [YOUR_Util_Class createNavigationBarWithBackgroundImage:navigationBarBackgroundImage title:nil];
 4 [self.view addSubview:customNavigationBar];
 5 
 6 UIButton *backButton = [[UIButton alloc] initWithFrame:CGRectMake(0.0, 0.0, 75.0, 30.0)];
 7 if (_backButtonImage) {
 8        [backButton setImage:_backButtonImage forState:UIControlStateNormal];
 9 }else {
10        [backButton setImage:[UIImage imageNamed:@"btnback.png"] forState:UIControlStateNormal];
11 }
12 
13 [backButton addTarget:self action:@selector(backButtonCliked:) forControlEvents:UIControlEventTouchUpInside];
14 UIBarButtonItem *backBarButton = [[UIBarButtonItem alloc] initWithCustomView:backButton];
15 customNavigationBar.topItem.leftBarButtonItem = backBarButton;
16 
17 [backButton release];
18 [backBarButton release];
19 
20 UIButton *addButton = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 43, 30)];
21 UIBarButtonItem *addBarButton = [[UIBarButtonItem alloc] initWithCustomView:addButton];
22 if (_isFromFavorites) {
23        [addButton setImage:[UIImage imageNamed:@"btn-delete-0.png"] forState:UIControlStateNormal];
24        [addButton addTarget:self action:@selector(deleteButtonClicked:) forControlEvents:UIControlEventTouchUpInside];
25 }else {
26         [addButton setImage:[UIImage imageNamed:@"btn_add.png"] forState:UIControlStateNormal];
27         [addButton addTarget:self action:@selector(addButtonClicked:) forControlEvents:UIControlEventTouchUpInside];
28 }
29 customNavigationBar.topItem.rightBarButtonItem = addBarButton;
30 [addButton release];
31 [addBarButton release];

複製代碼

此代碼如下：

這一方法轉載自：http://www.cnblogs.com/moshengren/archive/2010/10/18/1855191.html

方法三：也是自訂導航條類別，但是重寫setBackgroundImage:方法
CustomNavController.h

 1 //  Created by suruiqiang on 8/3/10.
 2 //  Copyright 2010 __MyCompanyName__. All rights reserved.
 3 //
 4 #pragma once
 5 #import <UIKit/UIKit.h>
 6 @interface UINavigationBar (UINavigationBarCategory) 
 7 UIImageView *bg;
 8 -(UINavigationBar*)setBackgroundImage:(UIImage*)image;
 9 - (void)insertSubview:(UIView *)view atIndex:(NSInteger)index;
10 @end

複製代碼

CustomNavController.m

 1 #import "CustomerNavBarController.h"
 2 
 3 @implementation UINavigationBar (UINavigationBarCategory)
 4 -(UINavigationBar*)setBackgroundImage:(UIImage*)image
 5 {
 6     UINavigationBar *NavBar = [[UINavigationBar alloc] initWithFrame:CGRectMake(0, 0, 320, 44)];
 7     if(image == nil) return NavBar;
 8     bg = [[UIImageView alloc]initWithImage:image];
 9     bg.frame = CGRectMake(0.f, 0.f, self.frame.size.width, self.frame.size.height);
10     [NavBar addSubview:bg];
11     [NavBar sendSubviewToBack:bg];
12     [bg release];
13     return NavBar;
14 }
15 
16 - (void)insertSubview:(UIView *)view atIndex:(NSInteger)index
17 {
18     [super insertSubview:view atIndex:index];
19     [self sendSubviewToBack:bg];
20 }
21 @end

複製代碼

調用程式碼範例：

- (void)viewDidLoad {
   [super viewDidLoad];
   [[self.navigationController navigationBar] setBackgroundImage:[UIImage imageNamed:@"NavigationBarBackground.png"]];

//在下面添加你自己的功能代碼
***********
}

此方法轉載自：http://www.cnblogs.com/moshengren/archive/2010/10/18/1855202.html

方法四：通過匯入QuartzCore架構繪製CALayer層來自訂

#import <QuartzCore/QuartzCore.h>

@interface DDNavigationViewController : UINavigationController<UINavigationControllerDelegate> {

    CALayer *_barBackLayer;

}

@end

 

View Code

 1 @implementation DDNavigationViewController
 2 
 3 - (id)initWithRootViewController:(UIViewController *)rootViewController {
 4 
 5     self = [super initWithRootViewController:rootViewController];
 6 
 7     self.delegate = self;
 8 
 9     return self;
10 
11 }
12 
13 - (void)loadView {
14 
15     [super loadView];
16 
17     UINavigationBar *bar = self.navigationBar;
18 
19     CALayer*layer = [CALayer layer];
20 
21     UIImage *navBarImage = [UIImage imageNamed:@"navigationBarBackground.png"];
22 
23     layer.contents = (id)navBarImage.CGImage;
24 
25     layer.frame= CGRectMake(0, 0, 320, navBarImage.size.height);
26 
27     [bar.layer insertSublayer:layer atIndex:0];
28 
29     _barBackLayer = layer;
30 
31 }  
32 
33 
34 #pragma mark -
35 
36 #pragma mark UINavigationControllerDelegate
37 
38 - (void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated {
39 
40     [_barBackLayer removeFromSuperlayer];
41 
42     [navigationController.navigationBar.layer insertSublayer:_barBackLayeratIndex:0];
43 
44 }
45 
46 @end