相关疑难解决方法(0)

我有一个UINavigationController我推几个视图.在viewDidLoad其中一个视图中,我想将其设置self.navigationItem.backBarButtonItem为自定义视图(基于自定义图像).我不知道为什么,但似乎没有用.相反,我得到了标准的"后退"按钮.

UIButton *backButton = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 63, 30)];
[backButton setImage:[UIImage imageNamed:@"back_OFF.png"] forState:UIControlStateNormal];
[backButton setImage:[UIImage imageNamed:@"back_ON.png"] forState:UIControlStateSelected];
UIBarButtonItem *backButtonItem = [[UIBarButtonItem alloc] initWithCustomView:backButton];
self.navigationItem.backBarButtonItem = backButtonItem;
[backButtonItem release];
[backButton release];

我测试了一个标准的标题,它的工作原理.上面的代码有什么问题？

self.navigationItem.backBarButtonItem = [[[UIBarButtonItem alloc] initWithTitle:@"Prout" style:UIBarButtonItemStyleDone target:nil action:nil] autorelease];

感谢您的帮助.

我想在导航栏中使用自定义项目作为后退按钮.

UIImage *backButtonImage = [UIImage imageNamed:@"backbutton.png"];
UIBarButtonItem *customItem = [[UIBarButtonItem alloc] initWithImage:backButtonImage style:UIBarButtonItemStylePlain target:nil action:nil];
[self.navigationItem setBackBarButtonItem: customItem];
[customItem release];

我最终得到的是我周围有边框的图像.它看起来像这样(我的图像是后退按钮):

我该怎样摆脱边界？我究竟做错了什么？