相册

<UINavigationControllerDelegate,UIImagePickerControllerDelegate>

-(void)setHeadPortrait
{
    /**
     *  添加手势：也就是当用户点击头像了之后，对这个操作进行反应
     */
    //允许用户交互
    self.ivHeadPortrait.userInteractionEnabled = YES;
    //初始化一个手势
    UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc]initWithTarget:self
                                                                               action:@selector(alterHeadPortrait:)];
    //给ImageView添加手势
    [self.ivHeadPortrait addGestureRecognizer:singleTap];
}

//  方法：alterHeadPortrait
-(void)alterHeadPortrait:(UITapGestureRecognizer *)gesture
{
    /**
     *  弹出提示框
     */
    //初始化提示框
    UIAlertController *alert = [UIAlertController alertControllerWithTitle:nil message:nil preferredStyle:UIAlertControllerStyleActionSheet];
    //按钮：从相册选择，类型：UIAlertActionStyleDefault
    [alert addAction:[UIAlertAction actionWithTitle:@"从相册选择" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
        //初始化UIImagePickerController
        UIImagePickerController *PickerImage = [[UIImagePickerController alloc]init];
        //获取方式1：通过相册（呈现全部相册），UIImagePickerControllerSourceTypePhotoLibrary
        //获取方式2，通过相机，UIImagePickerControllerSourceTypeCamera
        //获取方法3，通过相册（呈现全部图片），UIImagePickerControllerSourceTypeSavedPhotosAlbum
        PickerImage.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
        //允许编辑，即放大裁剪
        PickerImage.allowsEditing = YES;
        //自代理
        PickerImage.delegate = self;
        //页面跳转
        [self presentViewController:PickerImage animated:YES completion:nil];
    }]];
    //按钮：拍照，类型：UIAlertActionStyleDefault
    [alert addAction:[UIAlertAction actionWithTitle:@"拍照" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action){
        /**
         其实和从相册选择一样，只是获取方式不同，前面是通过相册，而现在，我们要通过相机的方式
         */
        UIImagePickerController *PickerImage = [[UIImagePickerController alloc]init];
        //获取方式:通过相机
        PickerImage.sourceType = UIImagePickerControllerSourceTypeCamera;
        PickerImage.allowsEditing = YES;
        PickerImage.delegate = self;
        [self presentViewController:PickerImage animated:YES completion:nil];
    }]];
    //按钮：取消，类型：UIAlertActionStyleCancel
    [alert addAction:[UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:nil]];
    [self presentViewController:alert animated:YES completion:nil];
}

//PickerImage完成后的代理方法
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info
{
    //定义一个newPhoto，用来存放我们选择的图片。
    UIImage *newPhoto = [info objectForKey:@"UIImagePickerControllerEditedImage"];
    self.ivHeadPortrait.image = newPhoto;
    [self dismissViewControllerAnimated:YES completion:nil];
}