1.中间弹出效果：

UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"提示" message:@"message" preferredStyle:UIAlertControllerStyleAlert];

UIAlertAction *cancel = [UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {

}];

UIAlertAction *confirm = [UIAlertAction actionWithTitle:@"确定" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action){

//确定要做的事

}];

[alert addAction:cancel];

[alert addAction:confirm];

[self presentViewController:alert animated:YES completion:nil];

}

2.从下往上弹出效果：（以调用相册为例）

@interface ViewController ()

遵守协议：UIImagePickerControllerDelegate,UINavigationControllerDelegate

UIAlertController *alertController = [UIAlertController alertControllerWithTitle:nil

message:nil

preferredStyle:UIAlertControllerStyleActionSheet];

UIAlertAction* cancelAction = [UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel

handler:^(UIAlertAction * action) {}];

UIAlertAction* fromPhotoAction = [UIAlertAction actionWithTitle:@"从相册选择" style:UIAlertActionStyleDefault                                                                handler:^(UIAlertAction * action) {                                                                    UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];

imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

imagePicker.modalTransitionStyle = UIModalTransitionStyleCoverVertical;

imagePicker.allowsEditing = YES;

// imagePicker.allowsEditing = NO;

imagePicker.delegate = self;

[self presentViewController:imagePicker animated:YES completion:nil];

}];

UIAlertAction* fromCameraAction = [UIAlertAction actionWithTitle:@"相机" style:UIAlertActionStyleDefault                                                            handler:^(UIAlertAction * action) {

if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])

{

UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];

imagePicker.delegate = self;

imagePicker.allowsEditing = YES;

//  imagePicker.allowsEditing = NO;

imagePicker.modalTransitionStyle = UIModalTransitionStyleCoverVertical;

imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;

[self presentViewController:imagePicker animated:YES completion:nil];

}

}];

[alertController addAction:cancelAction];

[alertController addAction:fromCameraAction];

[alertController addAction:fromPhotoAction];

[self presentViewController:alertController animated:YES completion:nil];

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

//  UIImage * image =info[UIImagePickerControllerOriginalImage];

UIImage *image = info[UIImagePickerControllerEditedImage];

self.myIconIV.image = image;

[self dismissViewControllerAnimated:YES completion:nil];

}