在iphone的uinavigationbar上使用图像或色调？

Question

如何在导航栏上显示背景图像或为本机iphone应用程序中的导航栏添加色调？

Answer 1

对于iOS5,请使用以下代码行:

UINavigationBar *navBar = [[self navigationController] navigationBar];
UIImage *backgroundImage = [UIImage imageNamed:@"nav-bar-background-normal"];
[navBar setBackgroundImage:backgroundImage forBarMetrics:UIBarMetricsDefault];

为了向后兼容,请检查导航栏是否响应setBackgroundImage:forBarMetrics:

更多信息:http: //sebastiancelis.com/2009/12/21/adding-background-image-uinavigationbar/

Answer 2

这就是我在iOS4上的表现:

#import <QuartzCore/QuartzCore.h> // For .layer 

self.navigationController.navigationBar.layer.contents = (id)[UIImage imageNamed:@"navigationBarBackgroundImage"].CGImage;
self.navigationController.navigationBar.tintColor = [UIColor orangeColor];

无需在z-orders(-exchangeSubviewAtIndex:withSubviewAtIndex :)之间切换子视图,在一行代码中设置背景图像和tintColor,并且也可以使用@ 2x图像.

Answer 3

一周前正在寻找这个.在此讨论发现了这一点.苹果.com/thread.jspa？threadID = 1649012&tstart = 0(抱歉不允许我发布真实链接).

-(void)setBackgroundImage:(UIImage*)image withTag:(NSInteger)bgTag{
if(image == NULL){ //might be called with NULL argument
    return;
}
UIImageView *aTabBarBackground = [[UIImageView alloc]initWithImage:image];
aTabBarBackground.frame = CGRectMake(0,0,self.frame.size.width,self.frame.size.height);
aTabBarBackground.tag = bgTag;
[self addSubview:aTabBarBackground];
[self sendSubviewToBack:aTabBarBackground];
[aTabBarBackground release];
}
/* input: The tag you chose to identify the view */
-(void)resetBackground:(NSInteger)bgTag {
    [self sendSubviewToBack:[self viewWithTag:bgTag]];
}

我把它作为UINavigationBar的一个类别.要在UINavigationBarController中为UINavigationBar设置背景图像,我这样做了:

[navigationControllerForChannels.navigationBar setBackgroundImage:[UIImage imageNamed:@"top_bar.png"] withTag:48151623];

更新标签栏时我有些瑕疵,所以你要打电话

[self.navigationController.navigationBar resetBackground:48151623];

对酒吧进行任何修改后.