iOS 判断相册权限、判断相机权限、判断定位权限

1.判断用户是否有权限访问相册

#import 
ALAuthorizationStatus author = [ALAssetsLibraryauthorizationStatus];
if (author == ALAuthorizationStatusRestricted || author ==ALAuthorizationStatusDenied){
    //无权限 做一个友好的提示
    UIAlertView * alart = [[UIAlertView alloc]initWithTitle:@"温馨提示" message:@"请您设置允许APP访问您的相册\n设置>隐私>照片" delegate:self cancelButtonTitle:@"确定" otherButtonTitles:nil, nil];
    [alart show];
    return ;
} else {
    //打开相册
}

ALAuthorizationStatus是一个系统的枚举。含义如下。

typedef NS_ENUM(NSInteger, AVAuthorizationStatus) {
AVAuthorizationStatusNotDetermined = 0,// 用户尚未做出选择这个应用程序的问候
AVAuthorizationStatusRestricted,// 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
AVAuthorizationStatusDenied,// 用户已经明确否认了这一照片数据的应用程序访问
AVAuthorizationStatusAuthorized// 用户已经授权应用访问照片数据
 } NS_AVAILABLE_IOS(7_0) __TVOS_PROHIBITED;

2、判断用户是否有权限访问相机
iOS7之前都可以访问相机，iOS7之后访问相机有权限设置

#import 
#import 
AVAuthorizationStatus authStatus = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
if (authStatus == AVAuthorizationStatusRestricted || authStatus ==AVAuthorizationStatusDenied)
{
    //无权限 做一个友好的提示
    UIAlertView * alart = [[UIAlertView alloc]initWithTitle:@"温馨提示" message:@"请您设置允许APP访问您的相机\n设置>隐私>相机" delegate:self cancelButtonTitle:@"确定" otherButtonTitles:nil, nil];
    [alart show];
    return ;
} else {
    //调用相机
}

3、判断定位服务是否可用

if ([CLLocationManager locationServicesEnabled] &&
    ([CLLocationManager authorizationStatus] == kCLAuthorizationStatusAuthorized
     || [CLLocationManager authorizationStatus] == kCLAuthorizationStatusNotDetermined)) {
        //定位功能可用，开始定位
        _locationManger = [[CLLocationManager alloc] init];
        locationManger.delegate = self;
        [locationManger startUpdatingLocation];
    }
else if ([CLLocationManager authorizationStatus] == kCLAuthorizationStatusDenied){
    NSlog("定位功能不可用，提示用户或忽略");
}