iOS后属性带UI_APPEARANCE_SELECTOR 可以统一设置全局作用
例如:
1>开关控件
@property(nullable, nonatomic, strong) UIColor *onTintColor NS_AVAILABLE_IOS(5_0) UI_APPEARANCE_SELECTOR;
可以统一设置开关的onTintColor样式.不过开关控件的颜色属性比较特殊
1.只在添加时作用一次.
2.添加结束后.
3.以后设置便不再改变.
4.也可以移出开关的父控件.而把开关从新加入到window上.
在iOS属性后有UI_APPEARANCE_SELECTOR标志都可以一次性统一设置.这种情况还有很多.比如说统一设置UITabbarItem的文字颜色 方法如下:
- (void)setTitleTextAttributes:(nullable NSDictionary*)attributes forState:(UIControlState)state NS_AVAILABLE_IOS(5_0) UI_APPEARANCE_SELECTOR;
appearance是apple在iOS5.0上加的一个协议，它让程序员可以很轻松地改变某控件的全局样式（背景）
@selector(appearance)
支持UIAppearance协议的类可以访问appearance selector ,它为receiver返回appearance proxy，我么可以给proxy发一些消息，诸如setTintColor:等
但是它并不是支持所有的UI类。下面列出它支持的类
1.UIActivitiIndicatorView
2.UIBarButtonItem
3.UIBarItem
4.UINavgationBar
5.UIPopoverControll
6.UIProgressView
7.UISearchBar
8.UISegmentControll
9.UISlider
10.UISwitch
11.UITabBar
12.UITabBarItem
13.UIToolBar
14.UIView
15.UIViewController
例如：
[[UINavigationBarappearance] setTintColor:[UIColorblackColor]];
[[UISearchBarappearance] setTintColor:[UIColorblackColor]];
注意：
初学者肯定会任意调用方法，大部分方法时无效的，如果调用时会抛出unknown selector 异常
那么如何查看你调用的方法时有效的呢，我们可以在此类的头文件中查看包含“UI_APPEARANCE_SELECTOR”常量的方法。
例如UIToolBar
它支持下列方法
@property(nonatomic,retain) UIColor *tintColor UI_APPEARANCE_SELECTOR;
- (void)setBackgroundImage:(UIImage *)backgroundImage forToolbarPosition:(UIToolbarPosition)topOrBottom barMetrics:(UIBarMetrics)barMetrics NS_AVAILABLE_IOS(5_0) UI_APPEARANCE_SELECTOR;
- (UIImage *)backgroundImageForToolbarPosition:(UIToolbarPosition)topOrBottom barMetrics:(UIBarMetrics)barMetrics NS_AVAILABLE_IOS(5_0) UI_APPEARANCE_SELECTOR;
- (void)setShadowImage:(UIImage *)shadowImage forToolbarPosition:(UIToolbarPosition)topOrBottom NS_AVAILABLE_IOS(6_0) UI_APPEARANCE_SELECTOR;
- (UIImage *)shadowImageForToolbarPosition:(UIToolbarPosition)topOrBottom NS_AVAILABLE_IOS(6_0) UI_APPEARANCE_SELECTOR;
了解更多请访问：http://developer.apple.com/library/ios/#documentation/uikit/reference/UIAppearance_Protocol/Reference/Reference.html。
补上实例代码:
+ (void) initialize
{
if (self == [DACircularProgressView class]) {
DACircularProgressView *circularProgressViewAppearance = [DACircularProgressView appearance];
[circularProgressViewAppearance setTrackTintColor:[[UIColor whiteColor] colorWithAlphaComponent:0.3f]];
[circularProgressViewAppearance setProgressTintColor:[UIColor whiteColor]];
[circularProgressViewAppearance setInnerTintColor:nil];
[circularProgressViewAppearance setBackgroundColor:[UIColor clearColor]];
[circularProgressViewAppearance setThicknessRatio:0.3f];
[circularProgressViewAppearance setRoundedCorners:NO];
[circularProgressViewAppearance setClockwiseProgress:YES];
[circularProgressViewAppearance setIndeterminateDuration:2.0f];
[circularProgressViewAppearance setIndeterminate:NO];
}
}
更多：
1.http://blog.csdn.net/lxl_815520/article/details/51360878
2.https://southpeak.github.io/2015/07/20/cocoa-uikit-uiapearance/
3.https://www.cnblogs.com/Rinpe/p/5351639.html
4.https://www.cnblogs.com/salam/archive/2013/01/30/appearance.html