我尝试以编程方式为我的应用中的标签栏设置背景图片。我的代码如下：
RootViewController.h
IBOutlet UITabBar *mainTabBar;
IBOutlet UITabBarItem *settingsBarItem;
IBOutlet UITabBarItem *infoBarItem;
IBOutlet UITabBarItem *aboutBarItem;
RootViewController.m
-(void)viewDidLoad {
UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"smallMenuBackground.png"]];
[mainTabBar insertSubview:imageView atIndex:0];
[imageView release];
[super viewDidLoad];
}
这对我不起作用。
更新
2012年1月23日更新
好的，我取得了一些进展。自从我升级到Xcode 4.2和IOS5后，这才停止工作。我设法使用Interface Builder中的选项将其恢复，但现在它仅适用于IOS5。理想情况下，我希望以编程方式开展工作，但我现在仍然愿意接受IB解决方案。
我似乎无法让它适用于任何以前的版本。
注意：我的TabBar仅在我的RootViewController上，这是我的应用程序的主屏幕。
理想情况下，如果我能让Nithin建议的代码正常工作，那就太棒了：
UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"tabBG.png"]];
if ([[[UIDevice currentDevice] systemVersion] floatValue] > 4.9) {
//iOS 5
[self.tabBarController.tabBar insertSubview:imageView atIndex:1];
}
else {
//iOS 4.whatever and below
[self.tabBarController.tabBar insertSubview:imageView atIndex:0];
}
[imageView release];
任何帮助都将不胜感激。
此致 斯蒂芬
答案 0 :(得分：14)
您可以为UITabBarController使用自定义类＆amp;覆盖tabBarController。在那里你可以设置你需要的按钮＆amp;他们对形象的行动。
这是您的自定义标签栏控制器类的外观：
// CustomTabBarController.h
#import <UIKit/UIKit.h>
@interface CustomTabBarController : UITabBarController {
UIButton *settingsButton;
UIButton *infoButton;
UIButton *aboutUsButton;
}
@property (nonatomic, retain) UIButton *settingsButton;
@property (nonatomic, retain) UIButton *infoButton;
@property (nonatomic, retain) UIButton *aboutUsButton;
-(void) addCustomElements;
-(void) selectTab:(int)tabID;
@end
// CustomTabBarController.m
#import "CustomTabBarController.h"
@implementation CustomTabBarController
@synthesize settingsButton, infoButton, aboutUsButton;
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
}
-(void)viewDidLoad
{
[super viewDidLoad];
[self addCustomElements];
}
-(void)addCustomElements
{
// Background
UIImageView* bgView = [[[UIImageView alloc] initWithImage:[UIImage imageNamed:@"tabBarBackground.png"]] autorelease];
bgView.frame = CGRectMake(0, 420, 320, 60);
[self.view addSubview:bgView];
// Initialise our two images
UIImage *btnImage = [UIImage imageNamed:@"settings.png"];
UIImage *btnImageSelected = [UIImage imageNamed:@"settingsSelected.png"];
self.settingsButton = [UIButton buttonWithType:UIButtonTypeCustom]; //Setup the button
settingsButton.frame = CGRectMake(10, 426, 100, 54); // Set the frame (size and position) of the button)
[settingsButton setBackgroundImage:btnImage forState:UIControlStateNormal]; // Set the image for the normal state of the button
[settingsButton setBackgroundImage:btnImageSelected forState:UIControlStateHighlighted]; // Set the image for the selected state of the button
[settingsButton setBackgroundImage:btnImageSelected forState:UIControlStateSelected]; // Set the image for the selected state of the button
[settingsButton setBackgroundImage:btnImageSelected forState:UIControlStateDisabled];
[settingsButton setImage:btnImageSelected forState:(UIControlStateHighlighted|UIControlStateSelected)];
[settingsButton setTag:101]; // Assign the button a "tag" so when our "click" event is called we know which button was pressed.
[settingsButton setSelected:true]; // Set this button as selected (we will select the others to false as we only want Tab 1 to be selected initially
// Now we repeat the process for the other buttons
btnImage = [UIImage imageNamed:@"info.png"];
btnImageSelected = [UIImage imageNamed:@"infoSelected.png"];
self.infoButton = [UIButton buttonWithType:UIButtonTypeCustom];
infoButton.frame = CGRectMake(110, 426, 100, 54);
[infoButton setBackgroundImage:btnImage forState:UIControlStateNormal];
[infoButton setBackgroundImage:btnImageSelected forState:UIControlStateSelected];
[infoButton setBackgroundImage:btnImageSelected forState:UIControlStateHighlighted];
[infoButton setImage:btnImageSelected forState:(UIControlStateHighlighted|UIControlStateSelected)];
[infoButton setTag:102];
btnImage = [UIImage imageNamed:@"aboutUs.png"];
btnImageSelected = [UIImage imageNamed:@"aboutUsSelected.png"];
self.aboutUsButton = [UIButton buttonWithType:UIButtonTypeCustom];
aboutUsButton.frame = CGRectMake(210, 426, 100, 54);
[aboutUsButton setBackgroundImage:btnImage forState:UIControlStateNormal];
[aboutUsButton setBackgroundImage:btnImageSelected forState:UIControlStateSelected];
[aboutUsButton setBackgroundImage:btnImageSelected forState:UIControlStateHighlighted];
[aboutUsButton setImage:btnImageSelected forState:(UIControlStateHighlighted|UIControlStateSelected)];
[aboutUsButton setTag:103];
// Add my new buttons to the view
[self.view addSubview:settingsButton];
[self.view addSubview:infoButton];
[self.view addSubview:aboutUsButton];
// Setup event handlers so that the buttonClicked method will respond to the touch up inside event.
[settingsButton addTarget:self action:@selector(buttonClicked:) forControlEvents:UIControlEventTouchUpInside];
[infoButton addTarget:self action:@selector(buttonClicked:) forControlEvents:UIControlEventTouchUpInside];
[aboutUsButton addTarget:self action:@selector(buttonClicked:) forControlEvents:UIControlEventTouchUpInside];
}
- (void)buttonClicked:(id)sender
{
int tagNum = [sender tag];
[self selectTab:tagNum];
}
- (void)selectTab:(int)tabID
{
switch(tabID)
{
case 101:
[settingsButton setSelected:true];
[infoButton setSelected:false];
[aboutUsButton setSelected:false];
break;
case 102:
[settingsButton setSelected:false];
[infoButton setSelected:true];
[aboutUsButton setSelected:false];
break;
case 103:
[settingsButton setSelected:false];
[infoButton setSelected:false];
[aboutUsButton setSelected:true];
break;
}
self.selectedIndex = tabID;
}
- (void)dealloc {
[settingsButton release];
[infoButton release];
[aboutUsButton release];
[super dealloc];
}
@end
希望这会对你有所帮助。
答案 1 :(得分：6)
UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"tabBG.png"]];
if ([[[UIDevice currentDevice] systemVersion] floatValue] > 4.9) {
//iOS 5
[self.tabBarController.tabBar insertSubview:imageView atIndex:1];
}
else {
//iOS 4.whatever and below
[self.tabBarController.tabBar insertSubview:imageView atIndex:0];
}
[imageView release];
答案 2 :(得分：3)
您需要通过操作系统版本对此进行有条件的编码。
如果您只支持iOS 5，则只需使用标签栏的backgroundImage属性即可。如果你需要支持低于5的iOS版本，你应该添加一些“破解”它的条件代码。有几种方法可以做到这一点，其中之一是：
答案 3 :(得分：2)
取自：http://ios-blog.co.uk/tutorials/ios-custom-ui-series-tabbar-navbar/
// Change the tab bar background
UIImage *tabBarBackground = [UIImage imageNamed:@"CustomUITabbar.png"];
[[UITabBar appearance] setBackgroundImage:tabBarBackground];
[[UITabBar appearance] setTintColor:[UIColor whiteColor]];
答案 4 :(得分：1)
就像之前在iOS 5上提到的那样，我建议你使用背景图片：
UITabBar *tabBar = tabController.tabBar;
if ([tabBar respondsToSelector:@selector(setBackgroundImage:)]) {
tabBar.backgroundImage = [UIImage imageNamed:@"TabBackground.png"];
}
始终使用respondsToSelector之类的检查，而不是显式版本检查。这样可以获得更安全，更具前瞻性的代码。
在iOS 4上，我建议你使用-[UITabBar drawRect:]方法，最好是在子类中。然后在Interface Builder中将UITabBarController s UITabBar自定义类（通常在MainWindow.xib中）设置为自定义子类。
但是，如果您没有使用MainWindow.xib，并且像iOS 5代码模板一样在代码中生成UITabBarController，则只能使用{{1}上的类别覆盖drawRect:方法}}
UITabBar这仅适用于iOS 4.x及更早版本的系统，但这很好，因为我们已经覆盖了iOS 5。
答案 5 :(得分：1)
正如Vinodh所说，您只需要识别每个案例，并使用-respondToSelector检查版本。我建议你在UITabBar上创建一个类别并轻松完成。因此代码将具有以下形式：
// UITabBar+Custom.h
#import <UIKit/UIKit.h>
#import <QuartzCore/QuartzCore.h>
@interface UITabBar (Custom)
-(void)setTabBarBackground:(UIImage *)backgroundImage;
@end
.m文件：
// UITabBar+Custom.m
#import "UITabBar+Custom.h"
#import <objc/runtime.h>
static char *backgroundImageKey;
-(void)setImage:(UIImage *)anImage {
objc_setAssociatedObject(self, &backgroundImageKey,
anImage, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
[self setNeedsDisplay];
}
-(UIImage *)image {
return objc_getAssociatedObject(self, &backgroundImageKey);
}
-(void)setTabBarBackground:(UIImage *)backgroundImage {
if([self respondsToSelector:@selector(setBackgroundImage:)]) {
[self setBackgroundImage:backgroundImage];
} else {
[self setImage:backgroundImage];
}
}
-(void)drawLayer:(CALayer *)layer inContext:(CGContextRef)ctx {
UIGraphicsPushContext(ctx);
UIImage *currentImage = [self image];
CGContextTranslateCTM(ctx, 0, currentImage.size.height);
CGContextScaleCTM(ctx, 1.0, -1.0);
CGContextDrawImage(ctx, self.bounds, currentImage.CGImage);
UIGraphicsPopContext();
}
-drawLayer:inContext将快速绘制背景图片。
答案 6 :(得分：1)
正如我在上面回答的那样，在不添加UIView的情况下，可以将背景图像添加到UITabBar，这个图像在您调用[tabBar setNeedsDisplay]时可能会消失，所以我想在-drawLayer:layer inContext:ctx中绘制图像（ -drawInRect:rect未被调用）。但是，如果您可以避免调用[tabBar setNeedsDisplay]，则可以采用一种简单的方法：
// UITabBar+Custom.m
#import "UITabBar+Custom.h"
#import <QuartzCore/QuartzCore.h>
-(void)setTabBarBackground:(UIImage *)backgroundImage {
if([self respondsToSelector:@selector(setBackgroundImage:)]) {
// ios 5+
[self setBackgroundImage:backgroundImage];
} else {
// ios 3.x / 4.x
self.layer.contents = (id)backgroundImage.CGImage;
}
}
答案 7 :(得分：0)
获取自定义视图并将其添加到UITaB栏上。现在在该视图上添加按钮，并提供方法链接到标签栏按钮。现在你可以通过添加图像或任何东西来对该视图做任何事情。它的工作方式与自定义标签栏类似。
答案 8 :(得分：0)
我过去所做的是创建我自己的TabbarController来加载不同的UIViewControllers。使用此控制器，我可以操纵其中的tabbar和tabbar项目的外观。
这对我来说很好，但它最初是一些工作。因为您必须“模拟”UITabBarController，因为您实际上并未使用“本机”UITabBar
答案 9 :(得分：0)
jUst call these two methods
hideTabBar;
addCustomElements;
hideTabBar method hides the original tabbar
And addCustomElements method will add the custom tabbar image as well as custom tabbar button also
- (void)hideTabBar
{
for(UIView *view in self.tabBarController.view.subviews)
{
// if([view isKindOfClass:[UITabBar class]])
// {
// view.hidden = YES;
// break;
// }
if([view isKindOfClass:[UITabBar class]])
{
[view setFrame:CGRectMake(view.frame.origin.x, 480, view.frame.size.width, view.frame.size.height)];
}
else
{
[view setFrame:CGRectMake(view.frame.origin.x, view.frame.origin.y, view.frame.size.width, 480)];
}
}
}
-(void)addCustomElements
{
// Initialise our two images
UIImage *btnImage = [UIImage imageNamed:@"homet.png"];
UIImage *btnImageSelected = [UIImage imageNamed:@"homehovert.png"];
self.btn1 = [UIButton buttonWithType:UIButtonTypeCustom]; //Setup the button
btn1.frame = CGRectMake(28, 446, 25,28); // Set the frame (size and position) of the button)
[btn1 setBackgroundImage:btnImage forState:UIControlStateNormal]; // Set the image for the normal state of the button
[btn1 setBackgroundImage:btnImageSelected forState:UIControlStateSelected]; // Set the image for the selected state of the button
[btn1 setTag:0]; // Assign the button a "tag" so when our "click" event is called we know which button was pressed.
[btn1 setSelected:true]; // Set this button as selected (we will select the others to false as we only want Tab 1 to be selected initially
// Now we repeat the process for the other buttons
btnImage = [UIImage imageNamed:@"blogt.png"];
btnImageSelected = [UIImage imageNamed:@"bloghovert.png"];
self.btn2 = [UIButton buttonWithType:UIButtonTypeCustom];
btn2.frame = CGRectMake(107, 448, 22,28);
[btn2 setBackgroundImage:btnImage forState:UIControlStateNormal];
[btn2 setBackgroundImage:btnImageSelected forState:UIControlStateSelected];
[btn2 setTag:1];
btnImage = [UIImage imageNamed:@"networkt.png"];
btnImageSelected = [UIImage imageNamed:@"networkhovert.png"];
self.btn3 = [UIButton buttonWithType:UIButtonTypeCustom];
btn3.frame = CGRectMake(180, 446, 35,29);
[btn3 setBackgroundImage:btnImage forState:UIControlStateNormal];
[btn3 setBackgroundImage:btnImageSelected forState:UIControlStateSelected];
[btn3 setTag:2];
btnImage = [UIImage imageNamed:@"contactt.png"];
btnImageSelected = [UIImage imageNamed:@"contacthovert.png"];
self.btn4 = [UIButton buttonWithType:UIButtonTypeCustom];
btn4.frame = CGRectMake(262, 447, 32,28);
[btn4 setBackgroundImage:btnImage forState:UIControlStateNormal];
[btn4 setBackgroundImage:btnImageSelected forState:UIControlStateSelected];
[btn4 setTag:3];
self.img1 = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@"tabbar.png"]] ;
img1.frame = CGRectMake(0, 440, 320, 40);
[self.tabBarController.view addSubview:img1];
// Add my new buttons to the view
[self.tabBarController.view addSubview:btn1];
[self.tabBarController.view addSubview:btn2];
[self.tabBarController.view addSubview:btn3];
[self.tabBarController.view addSubview:btn4];
// Setup event handlers so that the buttonClicked method will respond to the touch up inside event.
[btn1 addTarget:self action:@selector(buttonClicked:) forControlEvents:UIControlEventTouchUpInside];
[btn2 addTarget:self action:@selector(buttonClicked:) forControlEvents:UIControlEventTouchUpInside];
[btn3 addTarget:self action:@selector(buttonClicked:) forControlEvents:UIControlEventTouchUpInside];
[btn4 addTarget:self action:@selector(buttonClicked:) forControlEvents:UIControlEventTouchUpInside];
}
答案 10 :(得分：0)
// not supported on iOS4
UITabBar *tabBar = [tabController tabBar];
if ([tabBar respondsToSelector:@selector(setBackgroundImage:)])
{
// set it just for this instance
[tabBar setBackgroundImage:[UIImage imageNamed:@"tabbar_brn.jpg"]];
// set for all
// [[UITabBar appearance] setBackgroundImage: ...
}
else
{
// ios 4 code here
}
答案 11 :(得分：0)
// Change the tab bar background
UIImage* tabBarBackground = [UIImage imageNamed:@"tabbar.png"];
[[UITabBar appearance] setBackgroundImage:tabBarBackground];