扩展@Sven Tiffe 对 iOS 7 的回答,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。以下方法将使您不必创建两组图标图像(即选中与未选中),并且不必以编程方式加载它们。将类别方法 imageWithColor:(参见 - How can I change image tintColor in iOS and WatchKit)添加到您的项目中,然后将以下内容放入您的项目中自定义 UITabBarController viewDidLoad 方法:
// 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];
}
在 UIImage+Overlay.m 上创建一个名为 UIImage+Overlay 的类别(从 this answer 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