参考：https://blog.csdn.net/zhao15127334470/article/details/81216876

拍照

    UIAlertAction * takePhoto = [UIAlertAction actionWithTitle:DKLang(@"拍照", @"拍照") style:UIAlertActionStyleDefault handler:^(UIAlertAction *action){
        
        AVAuthorizationStatus authStatus = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
        
        if(authStatus == AVAuthorizationStatusRestricted || authStatus == AVAuthorizationStatusDenied){
            NSString *aleartMsg = @"";
            aleartMsg = @"请在\"设置 - 隐私 - 相机\"选项中，允许多客访问您的相机";
            
            UIAlertView * alert = [[UIAlertView alloc]initWithTitle:nil message:aleartMsg delegate:nil cancelButtonTitle:DKLang(@"OK", @"确定") otherButtonTitles:nil];
            [alert show];
            return;
        }
        //获取访问相机权限时，弹窗的点击事件获取
        [AVCaptureDevice requestAccessForMediaType:AVMediaTypeVideo completionHandler:^(BOOL granted) {
            if (granted) {
                debugLog(@"允许了");
                UIImagePickerControllerSourceType sourceType = UIImagePickerControllerSourceTypeCamera;
                //判断是否有摄像头
                if([UIImagePickerController isSourceTypeAvailable:sourceType])
                {
                    UIImagePickerController *imagePickerController = [[UIImagePickerController alloc] init];
                    imagePickerController.delegate = self;   // 设置委托
                    imagePickerController.sourceType = sourceType;
                    imagePickerController.allowsEditing = NO;
                    //需要以模态的形式展示
                    [self presentViewController:imagePickerController animated:YES completion:^{
                        
                    }];  
                } 
            } else {
                    debugLog(@"被拒绝了");
            }
        }];
        
    }];