iOS：警告：在演示过程中尝试在 <ViewController> 上呈现 <ModalViewController>
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iOS: Warning: Attempt to present <ModalViewController> on <ViewController>while a presentation is in progress
提问by alandalusi
I am trying to create a modal view controller after picking an image from the image picker. I use the code :
从图像选择器中选择图像后，我试图创建一个模态视图控制器。我使用代码：
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
NSLog(@"Picker has returned");
[self dismissModalViewControllerAnimated:YES];
// TODO: make this all threaded?
// crop the image to the bounds provided
img = [info objectForKey:UIImagePickerControllerOriginalImage];
NSLog(@"orig image size: %@", [[NSValue valueWithCGSize:img.size] description]);
// save the image, only if it's a newly taken image:
if([picker sourceType] == UIImagePickerControllerSourceTypeCamera){
UIImageWriteToSavedPhotosAlbum(img, nil, nil, nil);
}
// self.image_View.image=img;
//self.image_View.contentMode = UIViewContentModeScaleAspectFit;
ModalViewController *sampleView = [[ModalViewController alloc] init];
[self presentModalViewController:sampleView animated:YES];
}
However, I receive the warning:
但是，我收到警告：
Warning: Attempt to present <ModalViewController: 0x7561600> on <ViewController: 0x75a72e0> while a presentation is in progress!
and the modal view does not appear.
并且不会出现模态视图。
What am I doing wrong?
我究竟做错了什么？
回答by Moxy
- (void)imagePickerController:(UIImagePickerController *)picker
didFinishPickingMediaWithInfo:(NSDictionary *)info {
// TODO: make this all threaded?
// crop the image to the bounds provided
img = [info objectForKey:UIImagePickerControllerOriginalImage];
NSLog(@"orig image size: %@", [[NSValue valueWithCGSize:img.size] description]);
// save the image, only if it's a newly taken image:
if ([picker sourceType] == UIImagePickerControllerSourceTypeCamera) {
UIImageWriteToSavedPhotosAlbum(img, nil, nil, nil);
}
// self.image_View.image = img;
// self.image_View.contentMode = UIViewContentModeScaleAspectFit;
NSLog(@"Picker has returned");
[self dismissViewControllerAnimated:YES
completion:^{
ModalViewController *sampleView = [[ModalViewController alloc] init];
[self presentModalViewController:sampleView animated:YES];
}];
}
回答by Midhun MP
Here the issue is happening because, you are first dismissing the UIImagePickerand immediately you are displaying another view as modal view. That's why you are getting this error.
这里发生了问题，因为您首先关闭了，UIImagePicker然后立即将另一个视图显示为模态视图。这就是您收到此错误的原因。
Check with the following code:
检查以下代码：
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
[self dismissViewControllerAnimated:NO completion:^{
img = [info objectForKey:UIImagePickerControllerOriginalImage];
NSLog(@"orig image size: %@", [[NSValue valueWithCGSize:img.size] description]);
if([picker sourceType] == UIImagePickerControllerSourceTypeCamera)
{
UIImageWriteToSavedPhotosAlbum(img, nil, nil, nil);
}
ModalViewController *sampleView = [[ModalViewController alloc] init];
[self presentModalViewController:sampleView animated:YES];
}];
}
