A 控制器 Push 到 B 控制器 presentViewController（modal模态）到C控制器

A 控制器

#import "ViewController.h"
#import "B.h"
#import "C.h"
@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];
UIButton* button = [[UIButton alloc] initWithFrame:CGRectMake(0, 100, 60, 60)];
[button setTitle:@"AAA" forState:UIControlStateNormal];
button.backgroundColor = [UIColor redColor];

[button addTarget:self action:@selector(pushA) forControlEvents:UIControlEventTouchUpInside];

[self.view addSubview:button];
}

-(void)pushA
{
B* bVC = [[B alloc] init];

[self.navigationController pushViewController:bVC animated:YES];
}

@end

B 控制器

#import "B.h"
#import "C.h"
@interface B ()
@property(nonatomic,assign)BOOL isFromC;
@end

@implementation B

- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];

UIButton* button = [[UIButton alloc] initWithFrame:CGRectMake(50, 400, 60, 60)];
[button setTitle:@"BBB" forState:UIControlStateNormal];
button.backgroundColor = [UIColor greenColor];

[button addTarget:self action:@selector(pushC) forControlEvents:UIControlEventTouchUpInside];

[self.view addSubview:button];
}

-(void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];

if (self.isFromC) {
[self.navigationController popToRootViewControllerAnimated:YES];
}

}

-(void)pushC
{
C* ss = [[C alloc] init];

NSLog(@"导航 %p",self.navigationController);

[self.navigationController presentViewController:ss animated:YES completion:^{
self.isFromC = YES;
}];
}

@end

C 控制器

#import "C.h"
@interface C ()

@end

@implementation C

- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];

UIButton* button = [[UIButton alloc] initWithFrame:CGRectMake(50, 200, 100, 100)];
[button setTitle:@"CCC" forState:UIControlStateNormal];
button.backgroundColor = [UIColor orangeColor];

[button addTarget:self action:@selector(dissC) forControlEvents:UIControlEventTouchUpInside];

[self.view addSubview:button];
}

-(void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];

NSLog(@"MMMMM %p",self.presentingViewController);
//
//     UINavigationController* navi = (UINavigationController*)self.presentedViewController;
//    [navi popToRootViewControllerAnimated:YES];
}

-(void)dissC
{

NSLog(@"EEEEE %p",self.presentingViewController);

99be

[self dismissViewControllerAnimated:YES completion:^{

}];
}

@end