本文介绍了iOS 获取当前的ViewController,分享给大家。具体如下
通过简单的判断[UIViewController class],就认定它是想要的控制器是不对的:
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if ([nextResponder isKindOfClass:[UIViewController class ]]) {
result = nextResponder;
} else {
result = window.rootViewController;
}
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因为:isKindOfClass:确定一个对象是否是一个类的成员,或者是派生自该类的成员。
根据iOS的类图可以知道,UIViewController类还有好几个派生类,需要我们去区分的就是UITabBarController跟UINavigationController,拿到它们不是我们想要的。
1)UITabBarController通过属性viewControllers持有多个viewController;
2)UINavigationController通过压栈和出栈的方式持有或去除viewController;
3)UITableViewController就不用去判断了,它就是一个单个的viewController,而且更多的是手写创建tableView。
提供一个完整的方法:
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+ (UIViewController *)getCurrentViewController {
UIViewController *result = nil;
UIWindow * window = [[UIApplication sharedApplication] keyWindow];
//app默认windowLevel是UIWindowLevelNormal,如果不是,找到它
if (window.windowLevel != UIWindowLevelNormal) {
NSArray *windows = [[UIApplication sharedApplication] windows];
for (UIWindow * tmpWin in windows) {
if (tmpWin.windowLevel == UIWindowLevelNormal) {
window = tmpWin;
break ;
}
}
}
id nextResponder = nil;
UIViewController *appRootVC = window.rootViewController;
//1、通过present弹出VC,appRootVC.presentedViewController不为nil
if (appRootVC.presentedViewController) {
nextResponder = appRootVC.presentedViewController;
} else {
//2、通过navigationcontroller弹出VC
NSLog(@ "subviews == %@" ,[window subviews]);
UIView *frontView = [[window subviews] objectAtIndex:0];
nextResponder = [frontView nextResponder];
}
//1、tabBarController
if ([nextResponder isKindOfClass:[UITabBarController class ]]){
UITabBarController * tabbar = (UITabBarController *)nextResponder;
UINavigationController * nav = (UINavigationController *)tabbar.viewControllers[tabbar.selectedIndex];
//或者 UINavigationController * nav = tabbar.selectedViewController;
result = nav.childViewControllers.lastObject;
} else if ([nextResponder isKindOfClass:[UINavigationController class ]]){
//2、navigationController
UIViewController * nav = (UIViewController *)nextResponder;
result = nav.childViewControllers.lastObject;
} else { //3、viewControler
result = nextResponder;
}
return result;
}
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从上面代码中,可以衍生出获取当前tabBarController、navigationController,有时候可能就会用到。
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持服务器之家。
原文链接:http://www.jianshu.com/p/ee3c9b75d5f7?utm_source=tuicool&utm_medium=referral