UI基础 获取当前屏幕显示的viewcontroller

1 #pragma mark - 获取当前屏幕显示的viewcontroller
 2 - (UIViewController *)getCurrentVC
 3 {
 4     UIViewController *result = nil;
 5
 6     UIWindow * window = [[UIApplication sharedApplication] keyWindow];
 7     if (window.windowLevel != UIWindowLevelNormal)
 8     {
 9         NSArray *windows = [[UIApplication sharedApplication] windows];
10         for(UIWindow * tmpWin in windows)
11         {
12             if (tmpWin.windowLevel == UIWindowLevelNormal)
13             {
14                 window = tmpWin;
15                 break;
16             }
17         }
18     }
19
20     UIView *frontView = [[window subviews] objectAtIndex:0];
21     id nextResponder = [frontView nextResponder];
22
23     if ([nextResponder isKindOfClass:[UIViewController class]])
24         result = nextResponder;
25     else
26         result = window.rootViewController;
27
28     return result;
29 }

如果想进行push和pop，需要将调用方法得到的返回值强制类型转换为UINavigationController类型

1 UINavigationController *NC = (UINavigationController *)[self getCurrentVC];
2 [NC popViewControllerAnimated:YES];