我有这段代码可以在按下按钮时加载一个新的 UIView(来自 Storyboard )。按下按钮时触发 goPressed 函数,并调用 selectImage 函数。 selectImage 打开一个 UIImagePickerController 并让用户选择一张照片。用户选择照片后,didFinishPickingMediaWithInfo 委托(delegate)将所选图像添加到 UIImageView。
在“goPressed”中,在执行 selectImage 之后,它应该在评论为//1 时执行 Segue。但是没有任何反应。 performSegueWithIdentifier 似乎不起作用。如果我在调用 performSegueWithIdentifier 之前不调用 [self selectImage],它就可以工作。这是代码:
- (IBAction)goPressed:(id)sender {
[self selectImage];
[self performSegueWithIdentifier:@"lastView" sender:currentSender]; //1
}
-(void)selectImage
{
// Create image picker controller
UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];
// Set source to the camera
imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
// Delegate is self
imagePicker.delegate = (id)self;
// Allow editing of image ?
imagePicker.allowsEditing=NO;
// Show image picker
[self presentModalViewController:imagePicker animated:YES];
}
- (void) imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
// Access the uncropped image from info dictionary
UIImage *image = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
[[picker presentingViewController] dismissModalViewControllerAnimated:YES];
lePreview.image= image;
}
请帮忙,为什么 performSegueWithIdentifier 不起作用?希望我没有遗漏您需要的任何信息。
最佳答案
我假设您尝试转入的 View 使用的是您在转入之前获得的图片?如果他们从图像选择器中取消,你还想继续吗?
如果它需要图片,那么也许你应该在委托(delegate)调用“完成选择”之后调用你的 segue。
segue 未触发的问题可能是由于动画仍在此处发生:
[[picker presentingViewController] dismissModalViewControllerAnimated:YES];
你可以试试:
[[picker presentingViewController] dismissModalViewControllerAnimated:NO];
或者如果你想保持动画,将 segue 移动到“picker did finish”方法并这样做:
[self dismissModalViewControllerAnimated:YES completion:^() {
[self performSegueWithIdentifier:@"lastView" sender:self];
}];
或者如果这不起作用,请在 pickerdidfinish 方法中尝试这种方法(注意 - 这应该作为调用模态视图的 Controller 中的委托(delegate)实现,而不是模态视图本身:
//maintain the animation
[self dismissModalViewControllerAnimated:YES];
//slight pause to let the modal page dismiss and then start the segue
double delayInSeconds = 0.5;
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, delayInSeconds * NSEC_PER_SEC);
dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
//code to be executed on the main queue after delay
[self performSegueWithIdentifier:@"lastView" sender:self];
});
我经常使用这个过渡,它很好地离开了模态视图,然后在 segue View 中滑动,暂停让过渡看起来很自然。
关于objective-c - performSegueWithIdentifier 不工作,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/10464638/