跨视图控制器传输图像

Question

在我的iPhone应用程序上，我有两个viewController（firstViewController，secondViewController），在firstViewController上，用户可以从相机胶卷中选择一张照片，然后将其显示在imageView中，但是我还需要在secondViewController中显示它，但不知道如何到。

您能否也请深入解释您的答案，因为我对 Objective-C 相当陌生，

这是我的代码：

firstViewController.hfirstViewController.m

#import <UIKit/UIkit.h>

@interface firstViewController : UIViewController
<UIImagePickerControllerDelegate, UINavigationControllerDelegate>
{
    UIImageView *theImageView;
}

@property (nonatomic, retain) IBOutlet UIImageView *theImageView;
-(IBAction)selectExistingPicture;

@end

SecondViewController

#import "firstViewController.h"
#import "secondViewController.h"

@implementation firstViewController

@synthesize theImageView

-(IBAction) selectExistingPicture
{
    if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary])
    {
        UIImagePickerController *picker = [[UIImagePickerController alloc] init];
        picker.delegate = self;
        picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
        [self presentModalViewController:picker animated:YES];
        [picker release];
    }
}

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage : (UIImage *)image editingInfo:(NSDictionary *)editingInfo
{
    theImageView.image = image;
    [picker dismissModalViewControllerAnimated:YES];
}
-(void)imagePickerControllerDidCancel:(UIImagePickerController *)  picker
{
    [picker dismissModalViewControllerAnimated:YES];
}

-(IBAction)switchSecondViewController {

    SecondViewController *viewcontroller = [[SecondViewController alloc]     initWithNibName:@"SecondViewController" bundle:nil];
    [self presentModalViewController:viewcontroller animated:YES];
    [viewcontroller release];
}
// Default Apple code

@end

中没有太多内容，因此我不会费心发布该代码。

Answer 1

在第二个视图控制器中有一个类型的方法

-(void)setImage:(UIImage *)image

在创建视图控制器后，在下面的方法中调用带有图像的方法，如图所示

-(IBAction)switchSecondViewController {
    SecondViewController *viewcontroller = [[SecondViewController alloc] initWithNibName:@"SecondViewController" bundle:nil];
    [self presentModalViewController:viewcontroller animated:YES];
    [viewcontroller setImage:theImageView.image]
    [viewcontroller release];
}

Answer 2

您需要在第二个视图中声明一个属性，以便您可以从第一个视图中设置图像，如下所示：

secondaryImageView 是 secondaryView 中的属性，您必须设置它

-(IBAction)switchSecondViewController {

    SecondViewController *viewcontroller = [[SecondViewController alloc]     initWithNibName:@"SecondViewController" bundle:nil];
     viewcontroller.secondImageView.image = firstViewImage;
    [self presentModalViewController:viewcontroller animated:YES];
    [viewcontroller release];
}