如何设置UINavigationBar背景怎么换

来源：互联网发布：内向者适合做淘宝吗编辑：程序博客网时间：2024/04/28 10:38
利用objective-c的Category语法 扩展UINavigationBar 类具体代码为@implementation UINavigationBar (UINavigationBarCategory)- (void)drawRect:(CGRect)rect {    // Drawing code UIImage *img = [UIImage imageNamed: @"navbar_background.png"];CGPoint point = {0,0};[img drawAtPoint:point];}@end ////////////////////方法2////////////////////////////////////////////////////@implementation UINavigationBar (UINavigationBarCategory) - (void)drawRect:(CGRect)rect {//加入旋转坐标系代码    // Drawing codeUIImage *navBarImage = [UIImage imageNamed:@"LOGO_320×44.png"];CGContextRef context = UIGraphicsGetCurrentContext();CGContextTranslateCTM(context, 0.0, self.frame.size.height);CGContextScaleCTM(context, 1.0, -1.0);CGPoint center=self.center; CGImageRef cgImage= CGImageCreateWithImageInRect(navBarImage.CGImage,CGRectMake(0, 0, 1, 44));CGContextDrawImage(context, CGRectMake(center.x-160-80, 0, 80,self.frame.size.height), cgImage);CGContextDrawImage(context, CGRectMake(center.x-160, 0, 320,self.frame.size.height), navBarImage.CGImage);CGContextDrawImage(context, CGRectMake(center.x+160, 0, 80,self.frame.size.height), cgImage);}@endold codeCGContextDrawImage(context, CGRectMake(0, 0, self.frame.size.width,self.frame.size.height), navBarImage.CGImage);方法三：有了这个,你还会扩展drawRect自定义导航栏背景吗?查了很多资料,网上的自定义导航栏的方法,清一色的是扩展navigationBar的drawRect方法.然而这样的扩展会影响到工程里所有的navigationBar.或许你并不想这么做,而且很多不合常规的UI用这种方法根本没法实现.做了无数实验,尝试了各种方法,今天跟大家分享一个新方法:#import <QuartzCore/QuartzCore.h> @interface DDNavigationViewController : UINavigationController<UINavigationControllerDelegate> {    CALayer *_barBackLayer;} @end@implementation DDNavigationViewController - (id)initWithRootViewController:(UIViewController *)rootViewController {    self = [super initWithRootViewController:rootViewController];    self.delegate = self;    return self;}- (void)loadView {    [super loadView];        UINavigationBar *bar = self.navigationBar;     CALayer*layer = [CALayer layer];    UIImage *navBarImage = [UIImage imageNamed:@"navigationBarBackground.png"];    layer.contents = (id)navBarImage.CGImage;    layer.frame= CGRectMake(0, 0, 320, navBarImage.size.height);    [bar.layer insertSublayer:layer atIndex:0];    _barBackLayer = layer;} #pragma mark -#pragma mark UINavigationControllerDelegate- (void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated {    [_barBackLayer removeFromSuperlayer];    [navigationController.navigationBar.layer insertSublayer:_barBackLayeratIndex:0];}@end
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