xcode 如何在 iOS 5 中移除 UITabbaritem 的渐变/阴影
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How to remove gradient / drop shadow for UITabbaritem in iOS 5
提问by Desmond
with iOS 5, there is UI Appearance, is it possible to remove the gradient easy way ?
使用 iOS 5，有 UI Appearance，是否可以简单地去除渐变？
i do this to customised my tabbar, what can be done to remove the gradient ?
我这样做是为了自定义我的标签栏，可以做些什么来删除渐变？
thanks for reading
谢谢阅读
-(void)UIAppearances
{
//set the background of tab bar
UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"navbar_bgrd.png"]];
if ([[[UIDevice currentDevice] systemVersion] floatValue] > 4.9) {
//iOS 5
//[self.tabBarController.tabBar insertSubview:imageView atIndex:1];
[[UITabBar appearance] setBackgroundImage:[UIImage imageNamed:@"navbar_bgrd.png"]];
[[UITabBar appearance] setSelectionIndicatorImage:
[UIImage imageNamed:@"navbaractive.png"]];
[[UITabBarItem appearance] setTitleTextAttributes:
[NSDictionary dictionaryWithObjectsAndKeys:
[UIColor colorWithRed:75.0/255.0 green:75.0/255.0 blue:75.0/255.0 alpha:1.0], UITextAttributeTextColor,
[UIColor clearColor], UITextAttributeTextShadowColor,
[NSValue valueWithUIOffset:UIOffsetMake(0, 1)], UITextAttributeTextShadowOffset,
nil] forState:UIControlStateNormal];
[[UITabBarItem appearance] setTitleTextAttributes:
[NSDictionary dictionaryWithObjectsAndKeys:
[UIColor whiteColor], UITextAttributeTextColor,
[UIColor clearColor], UITextAttributeTextShadowColor,
[NSValue valueWithUIOffset:UIOffsetMake(0, 1)], UITextAttributeTextShadowOffset,
nil] forState:UIControlStateSelected];
//nav bar
[[UINavigationBar appearance] setTitleTextAttributes:
[NSDictionary dictionaryWithObjectsAndKeys:
[UIFont fontWithName:@"Rokkitt" size:28.0],
UITextAttributeFont,
nil]];
}
else {
//iOS 4.whatever and below
[self.tabBarController.tabBar insertSubview:imageView atIndex:0];
}
[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleBlackOpaque animated:NO];
}
回答by Jesper
UITabBar can either take an image and use its alpha channel (opacity) to build the selected/unselected images or take two processed images to use as is.
UITabBar 可以拍摄一张图像并使用其 alpha 通道（不透明度）来构建选择/未选择的图像，或者拍摄两张处理过的图像以原样使用。
You'll have to provide the images yourself to the UITabBarItem with setFinishedSelectedImage:withFinishedUnselectedImage:. There's no other way to affect the processing it does to the images besides changing the color of the gradient with UITabBar's selectedImageTintColorappearance property.
您必须自己将图像提供给 UITabBarItem setFinishedSelectedImage:withFinishedUnselectedImage:。除了使用 UITabBar 的selectedImageTintColor外观属性更改渐变颜色之外，没有其他方法可以影响它对图像所做的处理。
