• 相册授权判断

// 判断授权状态
        PHAuthorizationStatus status = [PHPhotoLibrary authorizationStatus];
        if (status == PHAuthorizationStatusRestricted) { // 此应用程序没有被授权访问的照片数据。可能是家长控制权限。
            NSLog(@"因为系统原因, 无法访问相册");
        } else if (status == PHAuthorizationStatusDenied) { // 用户拒绝访问相册
            UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"警告" message:@"请去-> [设置 - 隐私 - 相机 - 项目名称] 打开访问开关" delegate:self cancelButtonTitle:@"取消" otherButtonTitles:@"去设置", nil];
            [alertView show];
        } else if (status == PHAuthorizationStatusAuthorized) { // 用户允许访问相册
            // 放一些使用相册的代码
        } else if (status == PHAuthorizationStatusNotDetermined) { // 用户还没有做出选择
            // 弹框请求用户授权
            [PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) {
                if (status == PHAuthorizationStatusAuthorized) { // 用户点击了好
                  // 放一些使用相册的代码
                }
            }];
        }

• 相机授权判断

// 1、 获取摄像设备
    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    if (device) {
        // 判断授权状态
        AVAuthorizationStatus authStatus = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
        if (authStatus == AVAuthorizationStatusRestricted) {
            NSLog(@"因为系统原因, 无法访问相机");
            return;
        } else if (authStatus == AVAuthorizationStatusDenied) { // 用户拒绝当前应用访问相机
            UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"警告" message:@"请去-> [设置 - 隐私 - 相机 - 项目名称] 打开访问开关" delegate:self cancelButtonTitle:@"取消" otherButtonTitles:@"去设置", nil];
            [alertView show];
            return;
        } else if (authStatus == AVAuthorizationStatusAuthorized) { // 用户允许当前应用访问相机
            SGScanningQRCodeVC *scanningQRCodeVC = [[SGScanningQRCodeVC alloc] init];
            scanningQRCodeVC.delegate = self;
            [self presentViewController:scanningQRCodeVC animated:YES completion:nil];
        } else if (authStatus == AVAuthorizationStatusNotDetermined) { // 用户还没有做出选择
            // 弹框请求用户授权
            [AVCaptureDevice requestAccessForMediaType:AVMediaTypeVideo completionHandler:^(BOOL granted) {
                if (granted) {
                    // 用户接受
                    SGScanningQRCodeVC *scanningQRCodeVC = [[SGScanningQRCodeVC alloc] init];
                    scanningQRCodeVC.delegate = self;
                    [self presentViewController:scanningQRCodeVC animated:YES completion:nil];
                }
            }];
        }
    } else {
        UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"警告" message:@"未检测到您的摄像头, 请在真机上测试" delegate:self cancelButtonTitle:@"好的" otherButtonTitles:nil, nil];
        [alertView show];
    }

• UIAlertView的代理方法——跳转到系统设置的隐私中开启授权

#pragma mark - UIAlertViewDelegate
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
    if (buttonIndex == 1) {
        // 系统是否大于10
        NSURL *url = nil;
        if ([[UIDevice currentDevice] systemVersion].floatValue < 10.0) {
            url = [NSURL URLWithString:@"prefs:root=privacy"];
            
        } else {
            url = [NSURL URLWithString:UIApplicationOpenSettingsURLString];
        }
        [[UIApplication sharedApplication] openURL:url];
    }
}