判断相机权限：
NSString *mediaType = AVMediaTypeVideo;
AVAuthorizationStatus authStatus = [AVCaptureDevice authorizationStatusForMediaType:mediaType];
if(authStatus == AVAuthorizationStatusRestricted || authStatus == AVAuthorizationStatusDenied){
//相机权限受限制
}
typedef NS_ENUM(NSInteger, AVAuthorizationStatus) {
AVAuthorizationStatusNotDetermined = , 请问是否授权访问
AVAuthorizationStatusRestricted, 权限都限制
AVAuthorizationStatusDenied, 拒绝访问
AVAuthorizationStatusAuthorized 授权访问
} NS_AVAILABLE_IOS(7_0) __TVOS_PROHIBITED;
判断相册权限：
if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0){
PHAuthorizationStatus status = [PHPhotoLibrary authorizationStatus];
if (status == PHAuthorizationStatusDenied || status == PHAuthorizationStatusRestricted) {
//相册权限受限制
}
}
else{
ALAuthorizationStatus status = [ALAssetsLibrary authorizationStatus];
if (status == ALAuthorizationStatusDenied || status == ALAuthorizationStatusRestricted) {
//相册权限受限制
}
}
ALAuthorizationStatus 在iOS9之后废弃了，PHAuthorizationStatus 是ios8新增的替代 ALAuthorizationStatus 的方法。
typedef NS_ENUM(NSInteger, PHAuthorizationStatus) {
PHAuthorizationStatusNotDetermined = ,
PHAuthorizationStatusRestricted,
PHAuthorizationStatusDenied,
PHAuthorizationStatusAuthorized
} NS_AVAILABLE_IOS(8_0);
typedef NS_ENUM(NSInteger, ALAuthorizationStatus) {
ALAuthorizationStatusNotDetermined
ALAuthorizationStatusRestricted
ALAuthorizationStatusDenied
ALAuthorizationStatusAuthorized
} NS_DEPRECATED_IOS(6_0, 9_0, "Use PHAuthorizationStatus in the Photos framework instead");