Question

我正在制作一个用C ++制作的游戏，在某些时候想要打开使用相机。为此，它与Objective C类接口，该类呈现模态视图控制器：

UIImagePickerController* cameraUI = [[UIImagePickerController alloc] init];
cameraUI.sourceType = UIImagePickerControllerSourceTypeCamera;
cameraUI.mediaTypes = [[NSArray alloc] initWithObjects:(NSString*)kUTTypeImage, nil];
cameraUI.allowsEditing = YES;
cameraUI.delegate = self;

[[[[UIApplication sharedApplication] keyWindow] rootViewController] presentModalViewController:cameraUI animated:YES];

此类公开State变量以允许游戏观察模态视图控制器的进度。它是初学的：

State = CAMERA_ACTIVITY_WORKING;

由UIImageControllerDelegate函数更新：

- (void)imagePickerControllerDidCancel: (UIImagePickerController*) picker
{
  State = CAMERA_ACTIVITY_CANCELED;

  [[[[UIApplication sharedApplication] keyWindow] rootViewController] dismissModalViewControllerAnimated:YES];
  [picker release];
}

- (void)imagePickerController: (UIImagePickerController*) picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
  State = CAMERA_ACTIVITY_IMAGECAPTURED;

  [[[[UIApplication sharedApplication] keyWindow] rootViewController] dismissModalViewControllerAnimated:YES];
  [picker release];
}

模态视图控制器按原样打开和关闭，并且代理人肯定会被调用。但是，当游戏轮询状态变量时，它似乎尚未更新，返回CAMERA_ACTIVITY_WORKING。我尝试过变量volatile，但这没有效果。

有人可以帮忙吗？

编辑：完整的源代码

·H

@interface Camera : UIViewController<UIImagePickerControllerDelegate, UINavigationControllerDelegate>
{
    volatile State State;
    UIImage* CapturedImage;
}

- (void)imagePickerControllerDidCancel: (UIImagePickerController*) picker;

- (void)imagePickerController: (UIImagePickerController*) picker didFinishPickingMediaWithInfo:(NSDictionary *)info;

- (bool) IsAvailable;

- (bool) Show;

- (State) GetState;

@end

的.m

@implementation Camera

- (id)init
{
    self = [super init];
    if(!self) return self;

    State = CAMERA_ACTIVITY_WORKING;
    CapturedImage = NULL;

    return self;
}

- (void)imagePickerControllerDidCancel: (UIImagePickerController*) picker
{
    DEBUG_LOG("imagePickerControllerDidCancel");
    State = Poppet::ICameraActivity::CAMERA_ACTIVITY_CANCELED;
    DEBUG_LOG("State: " + STRING_CAST(State));

    [[[[UIApplication sharedApplication] keyWindow] rootViewController] dismissModalViewControllerAnimated:YES];
    [picker release];
}

- (void)imagePickerController: (UIImagePickerController*) picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{

    State = CAMERA_ACTIVITY_IMAGECAPTURED;

    [[[[UIApplication sharedApplication] keyWindow] rootViewController] dismissModalViewControllerAnimated:YES];
    [picker release];
}

- (bool) IsAvailable
{
    return [UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera] == YES;
}


- (bool) Show
{
    if(![self IsAvailable]) return false;

    State = CAMERA_ACTIVITY_WORKING;

    UIImagePickerController* cameraUI = [[UIImagePickerController alloc] init];
    cameraUI.sourceType = UIImagePickerControllerSourceTypeCamera; //Get Image From Camera
    cameraUI.mediaTypes = [[NSArray alloc] initWithObjects:(NSString*)kUTTypeImage, nil];
    cameraUI.allowsEditing = YES;
    cameraUI.delegate = self;

    [[[[UIApplication sharedApplication] keyWindow] rootViewController] presentModalViewController:cameraUI animated:YES];
    return true;
}

- (State) GetState
{ return State; }

@end

Answer 1

您好像没有使用自定义Camera类。

您创建了一个类

UIImagePickerController* cameraUI = [[UIImagePickerController alloc] init];

设置委托和其他一些项目并将其显示给用户。但这不是Camera类的实例，它是UIImagePickerController的实例。我相信你想做

Camera* cameraUI = [[Camera alloc] init];

这将为您提供自定义UIViewController的实现，但是还有另一个问题。您的Camera班级不是UIImagePickerController的子类，它是UIViewController的子类，因此它不会是UIImagePickerController。我认为你打算成为

@interface Camera : UIImagePickerController<UIImagePickerControllerDelegate, UINavigationControllerDelegate>

另一方面，命名约定说只有类名应以大写字母开头。方法名称和变量应以小写字母开头。

从评论中编辑：

您的Show方法似乎没有从任何地方调用，因此我不确定如何使用它。更重要的是，看看这个方法，我不确定如何使用它。开头的-表示它是一个实例方法，只能在Camera的实例上调用，但它用于创建和显示Camera的实例，因此该方法需要和用于创建和显示新创建的对象实例的对象的实例。可能不是意图。您可以使用+使其成为类方法并使用[Camera Show]调用它，但您将无法访问实例变量，因为它们不存在。

目前，我没有看到创建Camera的任何地方（Show之外）并且可能成为活动视图控制器，因此看起来您只是显示通用UIImagePickerController而不是你的自定义类。

在回调中更改时不保留变量

1 个答案: