当 UIView 的子视图不起作用时，在 UI Button 上点击方法

Question

点击 UIButton 时出现 EXC_BAD_ACCESS 错误。如果我将逻辑移动到RootViewController.m 它可以工作，但在我的PanelViewController.m 中实现时则不行。我不明白为什么这不起作用，我缺少什么以及如何使它起作用？

RootViewController.m

#import "RootViewController.h"
#import "PanelViewController.h"

@interface ListViewRootController ()

@end

@implementation ListViewRootController
    - (void)viewDidLoad {
        [super viewDidLoad];

        [self.view setFrame:CGRectMake(0, [[UIScreen mainScreen] bounds].size.height, [[UIScreen mainScreen] bounds].size.width, [[UIScreen mainScreen] bounds].size.height)];
        [self.view setBackgroundColor:[UIColor blueColor]];

        PanelViewController *panelView = [[PanelViewController alloc] init];

        [self.view addSubview:panelView.view];
    }
@end

PanelViewController.m

#import "PanelViewController.h"

@interface PanelViewController ()

@end

@implementation PanelViewController
    - (void)viewDidLoad {
        [super viewDidLoad];

        UIView *topBar = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, 60)];
        topBar.backgroundColor = [UIColor whiteColor];

        UIButton *mapButton = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, topBar.frame.size.height)];
        [mapButton setTitle:@"Map" forState:UIControlStateNormal];
        [mapButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
        [mapButton addTarget:self action:@selector(mapViewToggle:) forControlEvents:UIControlEventTouchDown];

        [self.view addSubview:topBar];
        [topBar addSubview:mapButton];
    }

    - (void)mapViewToggle:(UIButton *)sender{
         NSLog(@"hello, is it me youre looking for");
    }
@end

Answer 1

是的，不行，panelView控制器在这之后被释放

PanelViewController *panelView = [[PanelViewController alloc] init];

你应该在 RootViewController 的 .h 中有一个 var，类似于

@interface RootViewController : UIViewController {
  PanelViewController *panelView;
}

然后：

     panelView = [[PanelViewController alloc] init];

     [self.view addSubview:panelView.view];