UIPickerView UIImage 和 Segue答案

【问题标题】：UIPickerView UIImage and SegueUIPickerView UIImage 和 Segue
【发布时间】：2014-06-11 13:46:58
【问题描述】：

在我的应用程序中，我在 UserView 中使用带有 UIImagePickerCollection 的相机。但是一旦用户选择“使用照片”，我想将我的照片放在另一个视图中，即“cameraView”，因为我需要进行一些处理。这是我的代码：

-(void)takeAPicture{
NSLog(@"CHEESE");
UIImagePickerController *imagePicker =
[[UIImagePickerController alloc] init];

imagePicker.delegate = self;

imagePicker.sourceType =
UIImagePickerControllerSourceTypeCamera;

imagePicker.mediaTypes =
@[(NSString *) kUTTypeImage];

imagePicker.allowsEditing = NO;
[self presentViewController:imagePicker
                   animated:YES completion:nil];
}

-(void)imagePickerController:
(UIImagePickerController *)picker
didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    [self dismissViewControllerAnimated:YES completion:^{
    _img = [info objectForKey:UIImagePickerControllerOriginalImage];
    if ([picker sourceType] == UIImagePickerControllerSourceTypeCamera) {
        UIImageWriteToSavedPhotosAlbum(_img, nil, nil, nil);
    }}];
    [self performSegueWithIdentifier:@"toCameraView" sender:self];
}

-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
if ([[segue identifier] isEqualToString:@"toCameraView"])
        {
            CameraViewController *transferViewController = segue.destinationViewController;
        transferViewController.img = _img;
    }
}

当我运行我的应用程序时，我收到一条警告消息：

Warning: Attempt to present <CameraViewController: 0x17e20eb0> on <EIUserViewController: 0x189b1000> while a presentation is in progress!

我不明白它是什么，以及如何处理它，我无法在另一个视图中接收我的图像并在选择“使用图片”后直接显示我的视图。如果有人有解释或解决方案？谢谢你们！

【问题讨论】：

标签： ios objective-c uiimage uipickerview

【解决方案1】：

您正在尝试 [self performSegueWithIdentifier:@"toCameraView" sender:self] 在 UIImagePickerController 关闭期间，换句话说：无法为第一个 VC 消失期间出现的第二个 VC 设置动画。尝试移动 [self performSegueWithIdentifier:@"toCameraView" sender:self];在完成块内：

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    [self dismissViewControllerAnimated:YES completion:^{
    _img = [info objectForKey:UIImagePickerControllerOriginalImage];
    if ([picker sourceType] == UIImagePickerControllerSourceTypeCamera) {
        UIImageWriteToSavedPhotosAlbum(_img, nil, nil, nil);
    [self performSegueWithIdentifier:@"toCameraView" sender:self];
    }}];
}

【讨论】：

【解决方案2】：

所以，当 imagePicker 调用委托方法 imagePickerController: didFinishPickingMediaWithInfo: 时，imagePicker 仍然由您的 viewController 呈现。

一个解决方案是在您返回 viewController 时显示 cameraView，如下所示：

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    [self dismissViewControllerAnimated:YES completion:^{
    _img = [info objectForKey:UIImagePickerControllerOriginalImage];
    if ([picker sourceType] == UIImagePickerControllerSourceTypeCamera) {
        UIImageWriteToSavedPhotosAlbum(_img, nil, nil, nil);
    }}];
    self.newPicture = YES;
}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
    if (self.newPicture) {
        [self performSegueWithIdentifier:@"toCameraView" sender:self];
        self.newPicture = NO;
    }
}

希望对你有帮助

【讨论】：

- (void)viewDidAppear:(BOOL)animated 可以涉及 ViewController 的其他代码。最简单的方法是在没有 Bool 变量的情况下添加到 completionBlock