ios - Segue 无法正常工作

Question

我正在尝试让我的“主视图”允许用户选择一张照片并将其显示在我的“第二 View ”中。到目前为止，当按下按钮时，它允许用户选择照片并将其设置为 imageView 但是当我试图让它进入不同的 View 时我遇到了问题。这是我的用户选择按钮代码，底线是我试图用来切换 View 的代码。

- (IBAction)usePhotos:(id)sender {
    UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];
    imagePicker.delegate = self;
    imagePicker.sourceType =
    UIImagePickerControllerSourceTypePhotoLibrary;
    imagePicker.mediaTypes = @[(NSString *) kUTTypeImage];
    imagePicker.allowsEditing = YES;
    [self presentViewController:imagePicker animated:YES completion:nil];
    _newMedia = NO;
    [self performSegueWithIdentifier:@"switch" sender:self];
}

我也尝试过不同的方法，但它们都不起作用，所以我很困惑。预先感谢您!

Answer 1

据我了解，您需要首先拾取图像。一旦你有了一个，你想在第二个 View 上显示它。如果这是正确的，您的代码将无法工作，因为您呈现图像选择器并且您想要同时执行segue。尝试移动该行:

[self performSegueWithIdentifier:@"switch" sender:self];

到

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

    UIImage *image = info[UIImagePickerControllerEditedImage];

    // If you want to dismiss this view animated you should perform segue with delay (0.5 should be enough)
    [picker dismissViewControllerAnimated:NO completion:NULL];
    // You pass an image as a parameter so you can access it in prepareForSegue: method and you can pass it to destination view
    [self performSegueWithIdentifier:@"switch" sender:image];

}