iOS相机、麦克风等权限的判断与设置

一、iOS应用权限检测

在涉及到这个问题的时候，首先为了适配iOS10系统，我们必须首先在info.plist文件中声明将要用到的权限，否则将会引起崩溃如下：
“This app has crashed because it attempted to access privacy-sensitive data without a usage description. The app's Info.plist must contain an NSMicrophoneUsageDescription key with a string value explaining to the user how the app uses this data.”
那么设置权限声明的的方式如下：

屏幕快照 2017-01-09 下午7.52.07.png

我们需要点击Info.plist中加号，增加需要授权key值并填写相应的权限使用声明。

1.相机与麦克风

检测相机与麦克风权限需要导入AVFoundataion框架

#import <AVFoundation/AVFoundation.h>

 /**
//相机、麦克风的授权状态
typedef NS_ENUM(NSInteger, AVAuthorizationStatus) {
    AVAuthorizationStatusNotDetermined = 0,//未询问过用户是否授权
    AVAuthorizationStatusRestricted, //未授权，例如家长控制
    AVAuthorizationStatusDenied, //未授权，用户曾选择过拒绝授权
    AVAuthorizationStatusAuthorized //已经授权
} NS_AVAILABLE_IOS(7_0) __TVOS_PROHIBITED;
*/
//AVMediaTypeVideo:相机权限
//AVMediaTypeAudio：麦克风权限

/**
 检测相机的方法
 @param permissionGranted 相机授权成功执行的方法
 @param noPermission 相机授权失败或者未授权执行的方法
 */
+ (void)checkCameraAuthorizationGrand:(void (^)())permissionGranted withNoPermission:(void (^)())noPermission{
    AVAuthorizationStatus videoAuthStatus = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
    switch (videoAuthStatus) {
        case AVAuthorizationStatusNotDetermined:
        {
            //第一次提示用户授权
            [AVCaptureDevice requestAccessForMediaType:AVMediaTypeVideo completionHandler:^(BOOL granted) {
                granted ? permissionGranted() : noPermission();
            }];
            break;
        }
        case AVAuthorizationStatusAuthorized:
        {
            //通过授权
            permissionGranted();
            break;
        }
        case AVAuthorizationStatusRestricted:
            //不能授权
            NSLog(@"不能完成授权，可能开启了访问限制");
        case AVAuthorizationStatusDenied:{
            //提示跳转到相机设置(这里使用了blockits的弹窗方法）
            UIAlertView *alert = [UIAlertView  bk_showAlertViewWithTitle:@"相机授权" message:@"跳转相机授权设置" cancelButtonTitle:@"取消" otherButtonTitles:@[@"设置"] handler:^(UIAlertView *alertView, NSInteger buttonIndex) {
                if (buttonIndex == 1) {
                    //请求授权
                    [self requetSettingForVideo];
                 }
             }];
            [alert show];
        }
            break;
        default:
            break;
    }
}

2.相册

这里针对于iOS8及其以后的系统相册检测方法，使用到的PHPhotoLibrary需要导入Photos框架。

#import <Photos/Photos.h>

//相册的授权状态
typedef NS_ENUM(NSInteger, PHAuthorizationStatus) {
    PHAuthorizationStatusNotDetermined = 0, // User has not yet made a choice with regards to this application
    PHAuthorizationStatusRestricted,        // This application is not authorized to access photo data.
                                            // The user cannot change this application’s status, possibly due to active restrictions
                                            //   such as parental controls being in place.
    PHAuthorizationStatusDenied,            // User has explicitly denied this application access to photos data.
    PHAuthorizationStatusAuthorized         // User has authorized this application to access photos data.
} PHOTOS_AVAILABLE_IOS_TVOS(8_0, 10_0);

/**
 检测访问相册的权限
 这里的方法适用于iOS8及其以后版本
 @param permissionGranted 相册授权成功执行的方法
 @param noPermission 相册授权失败或者未授权执行的方法
 */
+ (void)checkPhotoAlbumAuthorizationGrand:(void (^)())permissionGranted withNoPermission:(void (^)())noPermission{
    PHAuthorizationStatus photoAuthStatus = [PHPhotoLibrary authorizationStatus];
    switch (photoAuthStatus) {
        case PHAuthorizationStatusNotDetermined:
        {
            //第一次提示用户授权
            [PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) {
                status == PHAuthorizationStatusAuthorized ? permissionGranted() : noPermission();
            }];
            break;
        }
        case PHAuthorizationStatusAuthorized:
        {
            //已经通过授权
            permissionGranted();
            break;
        }
        case PHAuthorizationStatusRestricted:
            //不能授权
            NSLog(@"不能完成授权，可能开启了访问限制");
        case PHAuthorizationStatusDenied:{
            //提示跳转相册授权设置
            UIAlertView *alert = [UIAlertView  bk_showAlertViewWithTitle:@"相册授权" message:@"跳转相册授权设置" cancelButtonTitle:@"取消" otherButtonTitles:@[@"设置"] handler:^(UIAlertView *alertView, NSInteger buttonIndex) {
                if (buttonIndex == 1) {
                    [self requetSettingForPhotoAlbum];
                }
            }];
            [alert show];
            break;
        }
        default:
            break;
    }
}

二、iOS应用跳转权限设置

在iOS8以后的系统中，跳转设置使用如下方法：

+ (void)requetSettingForAuth{
    NSURL *url = [NSURL URLWithString:UIApplicationOpenSettingsURLString];
    if ([ [UIApplication sharedApplication] canOpenURL:url])
    {   
        [[UIApplication sharedApplication] openURL:url];
    }
}

三、使用注意

我们在检测授权的时候弹窗会有授权和不授权的回调，有时候我们会在这里处理一些自定义UI问题，这里一定要在主线程中进行，否则会出现崩溃等问题，回到主线程中的操作如下：

  dispatch_async(dispatch_get_main_queue(), ^{
           //处理UI问题            
});