Question

我使用Xcode 4.2中的Utility Application模板创建了一个非常基本的应用程序，其中我想要一个从我的MainViewController中可用的FlipsideViewController中的滑块或文本字段获得的整数变量。

我一直在寻找全局变量的小时，但找不到适合我特定情况的简单答案。

请帮忙

（注意：我非常擅长为IOS和目标C开发。尽可能多地为我解答你的答案！）

非常感谢

以下是我的代码的基本版本，显示了我想要做的事情。

FlipSideViewController.h

#import <UIKit/UIKit.h>

@class FlipsideViewController;

@protocol FlipsideViewControllerDelegate
- (void)flipsideViewControllerDidFinish:(FlipsideViewController *)controller;
@end

@interface FlipsideViewController : UIViewController

@property (weak, nonatomic) id <FlipsideViewControllerDelegate> delegate;

- (IBAction)done:(id)sender;
- (IBAction)sliderChange:(id)sender;
@property (weak, nonatomic) IBOutlet UILabel *sliderValueOnFlipside;

@end

FlipSideViewController.m

#import "FlipsideViewController.h"

@interface FlipsideViewController ()

@end

@implementation FlipsideViewController
@synthesize sliderValueOnFlipside;

- (void)viewDidLoad
{
    [super viewDidLoad];

}

- (void)viewDidUnload
{
    [self setSliderValueOnFlipside:nil];
    [super viewDidUnload];

}

- (BOOL)shouldAutorotateToInterfaceOrientation:    (UIInterfaceOrientation)interfaceOrientation
{
    return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}

#pragma mark - Actions

- (IBAction)done:(id)sender
{
    [self.delegate flipsideViewControllerDidFinish:self];
}

- (IBAction)sliderChange:(id)sender {
    UISlider *slider = (UISlider *) sender;
    int var = [slider value];

    sliderValueOnFlipside.text = [NSString stringWithFormat:@"Slider Value is %d",var];
}

@end

MainViewController.h

#import "FlipsideViewController.h"

@interface MainViewController : UIViewController <FlipsideViewControllerDelegate>

- (IBAction)showInfo:(id)sender;
@property (weak, nonatomic) IBOutlet UILabel *sliderValueOnMain;

@end

MainViewController.m

#import "MainViewController.h"

@interface MainViewController ()

@end

@implementation MainViewController
@synthesize sliderValueOnMain;

- (void)viewDidLoad
{
    [super viewDidLoad];



    sliderValueOnMain.text = [NSString stringWithFormat:@"Slider Value from flipside is %d", var];
}

- (void)viewDidUnload
{
    [self setSliderValueOnMain:nil];
    [super viewDidUnload];

}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}

#pragma mark - Flipside View

- (void)flipsideViewControllerDidFinish:(FlipsideViewController *)controller
{
    [self dismissModalViewControllerAnimated:YES];
}

- (IBAction)showInfo:(id)sender
{    
    FlipsideViewController *controller = [[FlipsideViewController alloc] initWithNibName:@"FlipsideViewController" bundle:nil];
    controller.delegate = self;
    controller.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
    [self presentModalViewController:controller animated:YES];
}

@end

我可以轻松获取滑块的值以显示在侧面视图上，但我也希望在主视图上显示该值。

Answer 1

在礼貌的编程圈子中，全局变量通常是不受欢迎的。

如果您希望MainViewController中的方法对FlipsideViewController中的状态更改做出反应，那么您可以使MVC成为FVC的委托，并在值发生变化时让FVC在MVC上调用方法。

这里有代表设计模式的一个很好的解释：http://mobiledevelopertips.com/objective-c/the-basics-of-protocols-and-delegates.html

在IOS Utility应用程序视图之间共享数据

1 个答案: