iphone - 为 UINavigationBar 上的后退按钮设置自定义图像

Question

我正在尝试为后退按钮设置自定义图像，当将新 View 插入堆栈时，该按钮会自动放置到导航栏上。

我尝试在父 viewController 的 viewDidLoad 中添加以下内容:

[[UIBarButtonItem appearance] setBackButtonBackgroundImage:[UIImage imageNamed:@"BackButton.png"] forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];

我也试过以下方法:

UIBarButtonItem *btn = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"BackButton.png"] style:UIBarButtonItemStyleBordered target:nil action:nil];
    self.navigationItem.backBarButtonItem = btn;

使用 UIAppearance 会产生非常奇怪的结果:

Answer 1

试试这段代码

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

然后像这样定义回退方法

- (void)goback
{
    [self.navigationController popViewControllerAnimated:YES];
}