iOS how to start the image picker - ios

Question

I have a UIButton and when the user clicks it, I want to start the image picker controller
I already configure what I think it is enough but I couldn't know what is the message that I have to pass to that image picker to start working
This is my code
#import "ImagePickerViewController.h"
#interface ImagePickerViewController ()
#property (weak, nonatomic) IBOutlet UIImageView *image;
#end
#implementation ImagePickerViewController
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
}
- (IBAction)SelectImage:(id)sender {
UIImagePickerController *imagePicker = [[UIImagePickerController alloc]init];
imagePicker.delegate = self;
imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
}
#end
I have already set the correct protocols:
#interface ImagePickerViewController : UIViewController < UINavigationControllerDelegate,UIImagePickerControllerDelegate>
#end

Answer 1

You need to present the UIImagePicker
- (IBAction)SelectImage:(id)sender
{
UIImagePickerController *imagePicker = [[UIImagePickerController alloc]init];
imagePicker.delegate = self;
imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
[self presentViewController:imagePicker animated:NO completion:nil];
}

Answer 2

You can show the picker with:
[self presentViewController:imagePicker animated:YES completion:NULL];
And then in your delegate callback imagePickerController:didFinishPickingMediaWithInfo you get the image and dismiss the picker again:
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
UIImage *image = info[UIImagePickerControllerEditedImage];
[picker dismissViewControllerAnimated:YES completion:NULL];
}

Answer 3

You have to tell your view controller class to show the UIImagePickerController.
Simply use
[self presentViewController:imagePicker animated:YES completion:nil];
This will present it modally. If you are running on an iPad, you instead have to present it in a popover controller, as follows:
Declare a new property in the #interface:
#property (nonatomic, strong) UIPopoverController* imagePickerPopover;
Present the popover controller e.g:
UIButton* button = sender;
self.imagePickerPopover = [[UIPopoverController alloc] initWithContentViewController:self.imagePicker];
[self.imagePickerPopover presentPopoverFromRect:button.frame inView:self.view permittedArrowDirections:UIPopoverArrowDirectionRight animated:YES];