Question

我想为每个导航项目（按钮）设置背景图像（通用）。

这些图像应该如何显示？

是否有固定的尺寸或是否可以创建重复的背景图像？

如何以编程方式更改此背景图像？

感谢您的帮助

更新：

我发现此代码用于更改此按钮的背景，但它无效。

UIImage *barButton = [UIImage imageNamed:@"button_background.png"];
    [[UIBarButtonItem appearance] setBackgroundImage:barButton forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];

我不知道应该是哪个尺寸。

P.S。我想改变按钮的背景就像你可以改变背景颜色一样（self.navigation.controller.nvigationBar.tintColor ..）

Answer 1

以下代码可能会解决您的问题

UIButton *backBtn     = [UIButton buttonWithType:UIButtonTypeCustom];  
UIImage *backBtnImage = [UIImage imageNamed:@"button_background.png"]  ;  
[backBtn setBackgroundImage:backBtnImage forState:UIControlStateNormal];  
[backBtn addTarget:self action:@selector(goback) forControlEvents:UIControlEventTouchUpInside];  
backBtn.frame = CGRectMake(0, 0, 54, 30);  
UIBarButtonItem *cancelButton = [[UIBarButtonItem alloc] initWithCustomView:backBtn] ;  
self.navigationItem.leftBarButtonItem = cancelButton;

Answer 2

你需要创建自定义后退按钮

检查此代码

UIBarButtonItem *backButton = [[UIBarButtonItem alloc] 
                               initWithImage:[UIImage imageNamed:@"yourImage.png"]
                                       style:UIBarButtonItemStyleBordered 
                                      target:nil 
                                      action:nil];

self.navigationItem.backBarButtonItem = backButton;
[backButton release];

让我知道它是否有效

干杯

Answer 3

类别怎么样？例如，您可以这样做：

@interface UIBarButtonItem(JFAdditions)

- (id)initWithTitle:(NSString *)title image:(UIImage*)img;//add target and action if need

@end

 @implementation UIBarButtonItem(JFAdditions)

 - (id)initWithTitle:(NSString *)title image:(UIImage*)img
 {
        UIButton * btn = [UIButton buttonWithType:UIButtonTypeCustom];
        //add background image and text on button, target and action if need, also
    self = [self initWithCustomView:btn];

    return self;
}

如何更改导航项目（按钮）的背景图像？

3 个答案: