iOS检测相机或者相册可用

#define OSVersionIsAtLeastiOS7   ([[UIDevice currentDevice].systemVersion floatValue]>= 7.0 ? YES:NO)  //定义的宏    

//检查相机是否可用

    if (OSVersionIsAtLeastiOS7) {

        NSString *mediaType = AVMediaTypeVideo;

        AVAuthorizationStatus authStatus = [AVCaptureDevice authorizationStatusForMediaType:mediaType];

        if (authStatus == AVAuthorizationStatusDenied) {

            

            UIAlertView *alertView =[[UIAlertView alloc]initWithTitle:nil message:@"请前往系统设置->隐私->相机，开启爱维宝贝权限" delegate:nil cancelButtonTitle:nil otherButtonTitles:@"确定", nil];

            [alertView show];

            return;

        }

    }

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    //检查相册是否可用

    if (OSVersionIsAtLeastiOS7) {

        ALAuthorizationStatus authStatus = [ALAssetsLibrary authorizationStatus];

        if (authStatus == ALAuthorizationStatusDenied) {       

            UIAlertView *alertView =[[UIAlertView alloc]initWithTitle:nil message:@"请前往系统设置->隐私->相片，开启爱维宝贝权限" delegate:nil cancelButtonTitle:nil otherButtonTitles:@"确定", nil];

            [alertView show];

            return;

        }

        

    }