更改UINavigationBar背景图像 [英] Changing the UINavigationBar background image

问题描述

我一直在尝试更改应用程序的UINavigationBar的背景图像。我尝试了几种方法。首先，我在AppDelegate类中添加了以下代码：

I've been trying to change the background image of the UINavigationBar of my application. I tried several ways. First I added to my AppDelegate class the following code:

@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

但它无效。我的下一个尝试是编写一个CustomizedNavigationBar类，它覆盖了 drawRect 方法。看起来像这样：

But it wasn't working. My next try was to write a CustomizedNavigationBar Class which is overriding the drawRect method. It looked like that:

CustomizedNavigationBar.h

#import <UIKit/UIKit.h>

@interface CustomizedNavigationBar : UINavigationBar

@end

CustomizedNavigationBar.m

#import "CustomizedNavigationBar.h"

@implementation CustomizedNavigationBar

- (void) drawRect:(CGRect)rect {
    UIImage *image = [UIImage imageNamed: @"navigationbar.png"];
    [image drawInRect:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];

    NSLog(@"I got called!!!!!");
}

@end

在我的.xib文件中定义NavigationBar我将类更改为新的CustomizedNavigationBar。但它仍然没有用..

In my .xib file where the NavigationBar is defined I changed the class to the new CustomizedNavigationBar. But still it is not working..

作为另一个测试我下载了一个示例项目，其中应该更改背景图像。但即使使用该示例代码也无法正常工作。

As another test I downloaded an example project where the background image should be changed. But even with that sample code it was not working.

我做错了什么？我正在使用IOS 5.我可以定义背景图像的任何建议或其他方式吗？

What am I doing wrong? I am using IOS 5. Any suggestions or other ways I could define a background image?

感谢您的回答！

推荐答案

从iOS 5开始，你应该使用 setBackgroundImage：forBarMetrics： method：

Starting in iOS 5 you should use the setBackgroundImage:forBarMetrics: method:

[myNavbar setBackgroundImage:[UIImage imageNamed: @"UINavigationBarBackground.png"] 
               forBarMetrics:UIBarMetricsDefault];

并且在 Swift ：

navigationBar.setBackgroundImage(UIImage(named: "UINavigationBarBackground.png"),
               forBarMetrics: .Default)

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