Create action when I click on a button than UIAlertcontroller - ios

Question

i Create two buttons of UIAlertcontroller:
One Button - "OpenCamera"
Two button - "OpenGallery"
I just can not understand how I create action when I click on one of them.
- (IBAction)takePic:(id)sender {
UIAlertController *alert = [UIAlertController alertControllerWithTitle:nil
message:nil
preferredStyle:UIAlertControllerStyleActionSheet]; // 1
UIAlertAction *openCamrea = [UIAlertAction actionWithTitle:#"open camrea"
style:UIAlertActionStyleDefault handler:^(UIAlertAction * action) {
}];
UIAlertAction *openGallery = [UIAlertAction actionWithTitle:#"open gallery"
style:UIAlertActionStyleDefault handler:^(UIAlertAction * action) {
}];
[alert addAction:openCamrea];
[alert addAction:openGallery];
[self presentViewController:alert animated:YES completion:nil];
}

Answer 1

The handler is the block to be executed on the selection of the item.
UIAlertAction *openGallery = [UIAlertAction
actionWithTitle:#"open gallery"
style:UIAlertActionStyleDefault
handler:^(UIAlertAction * action) {
// Code to run when the open gallery option is pressed.
}];
BTW I think the long unbroken lines in the question really don't help as they effectively hide the key parameter.

Answer 2

The complete code:
- (IBAction)takePic:(id)sender {
UIAlertController *alert = [UIAlertController alertControllerWithTitle:nil
message:nil
preferredStyle:UIAlertControllerStyleActionSheet];
UIAlertAction *openCamrea = [UIAlertAction actionWithTitle:#"open camrea"
style:UIAlertActionStyleDefault handler:^(UIAlertAction * action)
{
if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
UIAlertView *myAlertView = [[UIAlertView alloc] initWithTitle:#"Error"message:#"Device has no camera"delegate:nil cancelButtonTitle:#"OK"otherButtonTitles: nil];
[myAlertView show];
}
else
{
UIImagePickerController *picker = [[UIImagePickerController alloc] init];
picker.delegate = self;
picker.allowsEditing = YES;
picker.sourceType = UIImagePickerControllerSourceTypeCamera;
[self presentViewController:picker animated:YES completion:NULL];
}
}];
UIAlertAction *openGallery = [UIAlertAction actionWithTitle:#"open gallery"
style:UIAlertActionStyleDefault handler:^(UIAlertAction * action)
{
UIImagePickerController *picker = [[UIImagePickerController alloc] init];
picker.delegate = self;
picker.allowsEditing = YES;
picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
[self presentViewController:picker animated:YES completion:NULL];
}];
[alert addAction:openCamrea];
[alert addAction:openGallery];
[self presentViewController:alert animated:YES completion:nil];
}
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
UIImage *chosenImage = info[UIImagePickerControllerEditedImage];
self.img.image = chosenImage;
[picker dismissViewControllerAnimated:YES completion:NULL];
}
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker {
[picker dismissViewControllerAnimated:YES completion:NULL];
}

Answer 3

Put your code inside the handler blocks you are passing to [UIAlertAction actionWithTitle:style:handler:]
For example:
UIAlertAction *openCamrea = [UIAlertAction actionWithTitle:#"open camrea"
style:UIAlertActionStyleDefault handler:^(UIAlertAction * action) {
// openCamera action code goes here
}];
UIAlertAction *openGallery = [UIAlertAction actionWithTitle:#"open gallery"
style:UIAlertActionStyleDefault handler:^(UIAlertAction * action) {
// openGallery action code goes here
}];