未选择的UITabBar颜色？

Question

我有一个有5个项目的UITabBar。我想改变所有项目的未选择颜色。这些项目没有在UIViewController类中声明（我构建了它们并链接了故事板中的视图）。

是否有这样的代码：[[UITabBar外观]set***UN***SseltedImageTintColor：[UIColor WhiteColor]]；？

Answer 1

将@Sven Tiffe的答案扩展到iOS7，您可以让您的代码自动为故事板中添加的未选择的UITabBar图像着色。以下方法将节省您创建两组图标图像（即选择的和未选择的）并以编程方式加载它们的时间。将类别方法Imagewith Color：（请参阅-如何在iOS和WatchKit中更改图像tintColor）添加到您的项目中，然后将以下内容放入您自定义的UITabBarController viewddLoad方法中：

// set the selected colors
[self.tabBar setTintColor:[UIColor whiteColor]];
[[UITabBarItem appearance] setTitleTextAttributes:[NSDictionary dictionaryWithObjectsAndKeys: [UIColor whiteColor], NSForegroundColorAttributeName, nil] forState:UIControlStateSelected];


UIColor * unselectedColor = [UIColor colorWithRed:184/255.0f green:224/255.0f blue:242/255.0f alpha:1.0f];

// set color of unselected text
[[UITabBarItem appearance] setTitleTextAttributes:[NSDictionary dictionaryWithObjectsAndKeys:unselectedColor, NSForegroundColorAttributeName, nil]
                                         forState:UIControlStateNormal];

// generate a tinted unselected image based on image passed via the storyboard
for(UITabBarItem *item in self.tabBar.items) {
    // use the UIImage category code for the imageWithColor: method
    item.image = [[item.selectedImage imageWithColor:unselectedColor] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
}

创建一个类别称为UIImage叠加和UIImage叠加. m（从这个答案中提取）：

@implementation UIImage(Overlay)

- (UIImage *)imageWithColor:(UIColor *)color1
{
        UIGraphicsBeginImageContextWithOptions(self.size, NO, self.scale);
        CGContextRef context = UIGraphicsGetCurrentContext();
        CGContextTranslateCTM(context, 0, self.size.height);
        CGContextScaleCTM(context, 1.0, -1.0);
        CGContextSetBlendMode(context, kCGBlendModeNormal);
        CGRect rect = CGRectMake(0, 0, self.size.width, self.size.height);
        CGContextClipToMask(context, rect, self.CGImage);
        [color1 setFill];
        CGContextFillRect(context, rect);
        UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
        return newImage;
}
@end

Answer 2

据我所知，这在iOS7下是行不通的。特别是，选项卡栏的tintColor将定义选定选项卡的颜色，而不是未选定选项卡的颜色。如果你想在iOS7中更改默认值，似乎你必须实际使用不同的图标（以你喜欢的未选定选项卡的颜色）并设置文本的颜色。

此示例应将选定的选项卡着色为红色，并将其他选项卡呈现为绿色。在您的TabBarController中运行此代码：

// set color of selected icons and text to red
self.tabBar.tintColor = [UIColor redColor];
[[UITabBarItem appearance] setTitleTextAttributes:[NSDictionary dictionaryWithObjectsAndKeys: [UIColor redColor], NSForegroundColorAttributeName, nil] forState:UIControlStateSelected];


// set color of unselected text to green
[[UITabBarItem appearance] setTitleTextAttributes:[NSDictionary dictionaryWithObjectsAndKeys:[UIColor greenColor], NSForegroundColorAttributeName, nil]
                                         forState:UIControlStateNormal];

// set selected and unselected icons
UITabBarItem *item0 = [self.tabBar.items objectAtIndex:0];

// this way, the icon gets rendered as it is (thus, it needs to be green in this example)
item0.image = [[UIImage imageNamed:@"unselected-icon.png"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];

// this icon is used for selected tab and it will get tinted as defined in self.tabBar.tintColor
item0.selectedImage = [UIImage imageNamed:@"selected-icon.png"];

如果仅在故事板中设置图标，则只能控制所选选项卡的颜色（tintColor）。所有其他图标和相应文本将以灰色绘制。

也许有人知道采用iOS 7下的颜色更简单的方法？

Answer 3

在iOS 10及更高版本中，有3种可能的简单解决方案：

A.代码实例（Swift）：

self.tabBar.unselectedItemTintColor = unselectedcolor

B. IB实例：

添加类型为：Color

C.全球形象（Swift）：

UITabBar.appearance().unselectedItemTintColor = unselectedcolor