Question

我真的在苦苦挣扎，也许是因为我是Objective-C的新手，能够执行以下操作。

控制器MAViewControllerMenu（控制器1）拥有一个允许从库中选择图片的按钮
控制器MAViewControllerPictureDisplay（控制器2）拥有一个imageView（bigImageView）
一旦我从控制器1中的选择器中选择了一张图片，我想移动到下一个窗口（控制器2），然后让imageView保持我选择的图片。

问题： 1.它不会显示下一个控制器 2.它不会改变imageView来保存我选择的图片

观察： 1.当我在控制器1上使用imageView而不是2时，它就像我想要的那样保持图像 2.调试器显示调用控制器2类中更改imageView的函数。但是，即使我试图简单地更改标签，也没有任何变化。

代码： MAViewControllerMenu.h

 @interface MAViewControllerMenu : UIViewController     <UIImagePickerControllerDelegate,UINavigationControllerDelegate>
{
    UIImagePickerController *picker1;
    UIImagePickerController *picker2;
    UIImage *image;
    IBOutlet UIImageView *imageView;//THIS CHANGES,BUT IS IN CONTROLLER 1
}
- (IBAction)TakePhoto;
- (IBAction)ChooseExisting;
- (IBAction)movetonext;

MAViewControllerPictureDisplay.h

#import "MAViewControllerMenu.h"


@interface MAViewControllerPictureDisplay : UIViewController <UIImagePickerControllerDelegate,UINavigationControllerDelegate,menuControllerDelegate>
{


}

@property (weak, nonatomic) IBOutlet UIImageView *bigImageView;//THIS ONE WOULDNT HOLD THE CHOSEN IMAGE
@property (weak, nonatomic) IBOutlet UILabel *theLabel;
@property(nonatomic, strong) UIImage *image;

@end

实施

- (void)viewDidLoad
{

    [super viewDidLoad];
// Do any additional setup after loading the view.
    //load next page
    self.bigImageView.image = self.image;


}

在MAViewControllerMenu.m

#import "MAViewControllerMenu.h"
#import "MAViewControllerPictureDisplay.h"

@interface MAViewControllerMenu ()

@end

@implementation MAViewControllerMenu

MAViewControllerPictureDisplay* imageControllerView;

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    image = [info objectForKey:UIImagePickerControllerOriginalImage];
    [imageView setImage:image]; //WORKS ON CURRENT CONTROLLER
    //imageControllerView.theLabel.text = @"hhdhdhd"; //DIDNT WORK
    [imageControllerView.bigImageView setImage:image]; //UPDATE IMAGE AT CONTROLLER 2, DIDNT WORK
    [self dismissViewControllerAnimated:YES completion:NULL];
    [self movetonext];
}


- (IBAction)movetonext{
    [self presentViewController:imageControllerView animated:YES completion:nil];//MOVE TO NEXT WINDOW- DOESNT WORK WHEN INVOKED AFTER SELECTING A PICTURE. DOES WORK WHEN INVOKING,SAY, AFTER A BUTTON WAS CLICKED
}


- (void)viewDidLoad
{

    [super viewDidLoad];
// Do any additional setup after loading the view.
    //load next page
    imageControllerView = [[self storyboard] instantiateViewControllerWithIdentifier:@"chosenImageController"];


}

Answer 1

图片未显示在第二个视图控制器中，因为此时您正在设置图像的图像视图尚不存在。

[imageControllerView.bigImageView setImage:image];

声明UIImage property并使用它传递图像。然后在imageControllerView的{{1}}中显示viewDidLoad。例如：

UIImageView

Answer 2

不要那样做。您应该将另一个视图控制器的视图视为私有。 Reecon显示了执行此操作的正确方法（设置属性以保存信息，然后在viewDidLoad或vieWillAppear：animated中显示该信息）

如何从A类（控制器1的自定义类）更改B类（控制器2的自定义类）中的imageView？

2 个答案: