UITabBar 图像在 iOS 7 上无法正确显示

Question

我有这个标签栏在 iOS 8 上正常工作，但在 iOS 7 上没有，有人能指出我正确的方向吗，我使用 JSON 文件在加载第一个屏幕时配置我的 UITabBar。

我必须为 iOS 7 使用不同的图像吗？？

是否可以改变de Button的大小来避免这种行为？？

iOS 8：

iOS 7：

这是我用来加载图片的代码：

- (void)createTabBar
{
    tabController = [self.storyboard instantiateViewControllerWithIdentifier:@"cCustomTabController"];
    dValue = [dConfiguration objectForKey:@"Buttons"];
    NSMutableArray  *aControllers = [[NSMutableArray alloc] init];
    int i = 0;
    for (NSString* sProperty in dValue) {
        NSString* d = @"Details";
        NetworkStatus internetStatus = [_reachabilityInfo currentReachabilityStatus];
        NSData *itemData = Nil;
        if (internetStatus != NotReachable)
            itemData = [util getSpecificJsonData:[sProperty valueForKeyPath:@"Item"]];
        if(itemData != nil){
            UIStoryboard *aStoryboard = [UIStoryboard storyboardWithName:@"Main_iPhone" bundle:[NSBundle mainBundle]];
            UIViewController *vcCustom = [aStoryboard instantiateViewControllerWithIdentifier:[util getControllerName:[sProperty valueForKeyPath:@"ViewController"]]];
            UIImage *imageBtn = [UIImage imageNamed:[util getImageName:[sProperty valueForKeyPath:@"Image"] andRetrina:[sProperty valueForKeyPath:@"ImageRetina"]]];
            UIImage *imageBtnPress = [UIImage imageNamed:[util getImageName:[sProperty valueForKeyPath:@"ImageHeighlighted"] andRetrina:[sProperty valueForKeyPath:@"ImageRetinaHeighlighted"]]];
            UITabBarItem *tab = [[UITabBarItem alloc] initWithTitle:[sProperty valueForKeyPath:@"Title"] image:imageBtn selectedImage:imageBtnPress];
            UIImage * iSelected = imageBtnPress;
            iSelected = [iSelected imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
            [tab setSelectedImage:iSelected];
            tab.tag = i;
            if([[sProperty valueForKeyPath:@"Title"] isEqualToString:@"Notificaciones"])
                tab.badgeValue=[sProperty valueForKeyPath:@"Badge"];
            [vcCustom setTabBarItem:tab];
            [vcCustom setTitle:[sProperty valueForKeyPath:@"Title"]];
            [aControllers insertObject:navigationController atIndex:i];
            i++;
        }
        else
        {
            UIStoryboard *aStoryboard = [UIStoryboard storyboardWithName:@"Main_iPhone" bundle:[NSBundle mainBundle]];
            UIViewController *vcCustom = [aStoryboard instantiateViewControllerWithIdentifier:[util getControllerName:[sProperty valueForKeyPath:@"ViewController"]]];
            UIImage *imageBtn = [UIImage imageNamed:[util getImageName:[sProperty valueForKeyPath:@"Image"] andRetrina:[sProperty valueForKeyPath:@"ImageRetina"]]];
            UIImage *imageBtnPress = [UIImage imageNamed:[util getImageName:[sProperty valueForKeyPath:@"ImageHeighlighted"] andRetrina:[sProperty valueForKeyPath:@"ImageRetinaHeighlighted"]]];
            UITabBarItem *tab = [[UITabBarItem alloc] initWithTitle:[sProperty valueForKeyPath:@"Title"] image:imageBtn selectedImage:imageBtnPress];
            UIImage * iSelected = imageBtnPress;
            iSelected = [iSelected imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
            [tab setSelectedImage:iSelected];
            tab.tag = i;
            if([[sProperty valueForKeyPath:@"Title"] isEqualToString:@"Notificaciones"])
                tab.badgeValue=[sProperty valueForKeyPath:@"Badge"];
            [vcCustom setTabBarItem:tab];
            [vcCustom setTitle:[sProperty valueForKeyPath:@"Title"]];
            UINavigationController *navigationController = [[cCustomNavigationController alloc] initWithRootViewController:vcCustom];
            [aControllers insertObject:navigationController atIndex:i];
            i++;
        }


    }
    tabController.delegate = self;
    tabController.viewControllers = aControllers;
    tabController.tabBar.tintColor = [UIColor blackColor];
}

提前致谢。

Answer 1

确保使用包含@1x、@2x 和@3x 图像文件的资产目录来支持任何屏幕分辨率。

我个人使用 Mark Bridges 的Asset Catalog Creator 来创建不同的分辨率。

编辑：
导入多分辨率资产目录后，您可以使用[UIImage imageNamed:@"myImage"];或从界面生成器中选择它。 iOS 会自动选择好的。

Answer 2

确保使用包含@1x、@2x 和@3x 的资产目录。

示例：
yourimageName@2x~iphone.png for iphone,

  yourimageName@2x~ipad.png for ipad

Answer 3

我在代码中更改了这两行：

UIImage *imageBtn = [UIImage imageNamed:[util getImageName:[sProperty valueForKeyPath:@"Image"] andRetrina:[sProperty valueForKeyPath:@"ImageRetina"]]];

UIImage *imageBtnPress = [UIImage imageNamed:[util getImageName:[sProperty valueForKeyPath:@"ImageHeighlighted"] andRetrina:[sProperty valueForKeyPath:@"ImageRetinaHeighlighted"]]];

对于这 2 个：

UIImage *imageBtn = [self changeImageSize:[UIImage imageNamed:[util getImageName:[sProperty valueForKeyPath:@"Image"] andRetrina:[sProperty valueForKeyPath:@"ImageRetina"]]] scaledToSize:CGSizeMake(30, 30)];

UIImage *imageBtnPress = [self changeImageSize:[UIImage imageNamed:[util getImageName:[sProperty valueForKeyPath:@"ImageHeighlighted"] andRetrina:[sProperty valueForKeyPath:@"ImageRetinaHeighlighted"]]] scaledToSize:CGSizeMake(30, 30)];

并添加了改变图片大小的功能：

- (UIImage *)changeImageSize:(UIImage *)image scaledToSize:(CGSize)newSize {

    UIGraphicsBeginImageContextWithOptions(newSize, NO, 0.0);
    [image drawInRect:CGRectMake(0, 0, newSize.width, newSize.height)];
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return newImage;
}

我不知道这是否正确，但对我来说是有效的。

感谢大家，祝大家编码愉快。