Question

所以我正在尝试制作这款相机应用程序，但每当我尝试运行它时，它会显示“预期标识符或'（'。我得到其中两个错误。其中一个正确 - (IBAction)takePhoto:(UIButton *)sender;以及- (IBAction)selectPhoto:(UIButton *)sender;下的#import <UIKit/UIKit.h> @interface APPViewController : UIViewController <UIImagePickerControllerDelegate, UINavigationControllerDelegate> @property (strong, nonatomic) IBOutlet UIImageView *ImageView; - (IBAction)takePhoto:(UIButton *)sender; { UIImagePickerController *picker = [[UIImagePickerController alloc] init]; picker.delegate = self; picker.allowsEditing = YES; picker.sourceType =UIImagePickerControllerSourceTypeCamera; [self presentViewController:picker animated:YES completion:NULL]; } - (IBAction)selectPhoto:(UIButton *)sender; { UIImagePickerController *picker = [[UIImagePickerController alloc] init]; picker.delegate = self; picker.allowsEditing = YES; picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary; [self presentViewController:picker animated:YES completion:NULL]; } @end 感谢

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Answer 1

@interface（通常是.h文件）仅包含类接口。它不应该包含类实现（方法内容）。这是在.m文件中（具体来说，是@ implementation）。所以你需要把它移到那里。

Answer 2

如果您需要从课堂外调用您的方法，您必须将他们的签名放在.h文件中，如下所示：

@interface APPViewController : UIViewController <UIImagePickerControllerDelegate, UINavigationControllerDelegate>

- (IBAction)takePhoto:(UIButton *)sender;
- (IBAction)selectPhoto:(UIButton *)sender;

@end

然后在.m文件中你应该有这样的东西（我在私人界面中离开该属性，所以你看它应该是什么样子）

@interface APPViewController ()

@property (strong, nonatomic) IBOutlet UIImageView *ImageView;

@end

- (IBAction)takePhoto:(UIButton *)sender
{
 UIImagePickerController *picker = [[UIImagePickerController alloc] init];
    picker.delegate = self;
    picker.allowsEditing = YES;
    picker.sourceType =UIImagePickerControllerSourceTypeCamera;

    [self presentViewController:picker animated:YES completion:NULL];
}

- (IBAction)selectPhoto:(UIButton *)sender
{
    UIImagePickerController *picker = [[UIImagePickerController alloc] init];
    picker.delegate = self;
    picker.allowsEditing = YES;
    picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

    [self presentViewController:picker animated:YES completion:NULL];
}
@end

你应该注意.m文件中的内容：

方法名称后面没有分号
私有接口的声明（您忘记了@end并使用了.h文件@interface声明）
- 当你使用属性时也不要使用驼峰盒，因为你会感到困惑;使用较低的驼峰案例：

@property（强，非原子）IBOutlet UIImageView * ImageView;

应该是

@property（强，非原子）IBOutlet UIImageView * imageView;

不要忘记使用XCode自动完成功能来帮助您提高效率。

预期标识符或'（'编译Objective-C时

2 个答案: