ios – UIViewController removeFromSuperview错误

我有一个UIViewController然后当我长按到self.view它会推出一个弹出窗口(MenuViewController).但是当我尝试通过removeFromSuperview删除弹出窗口时,它仍会出现

您可以在此http://www.youtube.com/watch?v=nVVgmeJEnnY中查看我的问题的更多详细信息

ViewController.m

#import "MenuViewController.h"
@interface ViewController () {
    MenuViewController *menu;
}
....
- (void)viewDidLoad
{
    ....
    [[NSNotificationCenter defaultCenter] addobserver:self selector:@selector(albumButtonpressed : ) name:@"albumButtonpressed" object:nil];
    ....
}

....

-(void)albumButtonpressed : (NSNotification*) notification {
    UIImagePickerController *photoPicker = [[UIImagePickerController alloc] init];
    photoPicker.delegate = self;
    photoPicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

    [self presentModalViewController:photoPicker animated:YES];
}

...

-(void)handleLongPress:(UILongPressGestureRecognizer*)recognizer {
    menu = [[MenuViewController alloc] initWithNibName:@"MenuViewController" bundle:nil];
    if (self.imageView.image != nil) {
        menu.imageAdded = YES;
    }
    [self.view addSubview:menu.view];
}

MenuViewController.m

-(IBAction)albumButtonpressed:(id)sender {
    [self.view removeFromSuperview];
    [[NSNotificationCenter defaultCenter] postNotificationName:@"albumButtonpressed" object:nil];
}

解决方法

抛开我对不应用正确的视图控制器包含的保留,问题是你的handleLongPress将被多次调用不同的Recognizer.state值,一次作为UIGestureRecognizerStateBegan,再次作为UIGestureRecognizerStateEnded.你应该检查手势的状态,例如：

-(void)handleLongPress:(UILongPressGestureRecognizer*)recognizer {
    if (recognizer.state == UIGestureRecognizerStateEnded) {
        menu = [[MenuViewController alloc] initWithNibName:@"MenuViewController" bundle:nil];
        if (self.imageView.image != nil) {
            menu.imageAdded = YES;
        }
        [self.view addSubview:menu.view];
    }
}

原答案：

我建议使用removeFromSuperview在你的代码中放置一个NSLog或断点,看看你是否还得到那段代码.

这里有一些明显的问题.具体来说,您没有正确添加在handleLongPress中添加与MenuViewController关联的视图.如果你想要一个带有它自己的控制器的子视图,你必须使用包含(这只适用于iOS 5及更高版本).在收容中,你有像addChildViewController等关键方法.请参阅View Controller编程指南中的Creating Custom Container View Controllers或参见WWDC 2011 – Implementing UIViewController Containment.而且,除此之外,你还要保留对MenuViewController的强引用,所以即使你成功删除它也是如此看,你要泄漏控制器.

花一点时间浏览收容文档/视频,我想你会想重新审视你如何展示你的菜单.这是一个密集的阅读,但值得真正理解.遏制是强大的,但必须正确.