自定义UITabBar背景图片在iOS 5及更高版本中不起作用 [英] Custom UITabBar background image not working in iOS 5 and later

问题描述

我有一个简单的代码片段，在tabBar上放置一个背景图片。

  UIImageView * imageView = [[UIImageView alloc] initWithImage：[UIImage imageNamed：@tabBG.png]]; 
 [self.tabBarController.tabBar insertSubview：imageView atIndex：0]; 
 [imageView release]; 
 

这在iOS 4中工作正常，但是在iOS 5中测试时，它不工作。 p>



我试图做以下操作：

  UIImageView * imageView = [[UIImageView alloc] initWithImage：[UIImage imageNamed：@tabBG.png]]; 
 
 NSString * reqSysVer = @4.3; 
 NSString * iOSVersion = [[UIDevice currentDevice] systemVersion]; 
 
 if（[iOSVersion比较：reqSysVer选项：NSNumericSearch]！= NSOrderedDescending）{
 // iOS 4.3或更低版本的代码
 [self.tabBarController.tabBar insertSubView：imageView atIndex ：0]; 
} 
 else {
 // iOS 5的代码
 [self.tabBarController.tabBar insertSubView：imageView atIndex：1]; 
} 
 
 [imageView版本]; 
  

唉，这不行...任何人都可以提供解决方案吗？

解决方案

iOS5提供UIAppearance代理。

此外，最好的做法是切换代码基于能力（在这种情况下是respondtoSelector），而不是iOS版本 - 这是一个脆弱的假设（谁说，它不会改变在未来）。

可以为所有标签栏设置它：

  // iOS4不支持
 UITabBar * tabBar = [tabController tabBar]; 
 if（[tabBar respondingToSelector：@selector（setBackgroundImage :)]）
 {
 //仅为此实例设置
 [tabBar setBackgroundImage：[UIImage imageNamed：@tabbar_brn .jpg]]; 
 
 //为所有设置
 // [[UITabBar外观] setBackgroundImage：... 
} 
 else 
 {
 // ios 4 code here 
} 
  

I have a simple piece of code that places a background image on the tabBar.

UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"tabBG.png"]];
[self.tabBarController.tabBar insertSubview:imageView atIndex:0];
[imageView release];

This works fine in iOS 4 but when testing in iOS 5, it doesn't work.

I'm trying to do the following:

UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"tabBG.png"]];

NSString *reqSysVer = @"4.3";
NSString *iOSVersion = [[UIDevice currentDevice] systemVersion];

if ([iOSVersion compare:reqSysVer options:NSNumericSearch] !=NSOrderedDescending) {
    // code for iOS 4.3 or below
    [self.tabBarController.tabBar insertSubView:imageView atIndex:0];
}
else {
    // code for iOS 5
    [self.tabBarController.tabBar insertSubView:imageView atIndex:1];
}

[imageView release];

Alas, this isn't working... Can anyone offer a solution?

解决方案

iOS5 offers the UIAppearance Proxy.

Also, it's best practice to switch your code based on the capability (in this case it's respondsToSelector) instead of iOS version - that's a fragile assumption (who's to say it doesn't change in the future).

You can set it for just that instance or globally for all tab bars:

// 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
}

这篇关于自定义UITabBar背景图片在iOS 5及更高版本中不起作用的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！