iOS9 之后需要用户手动授予app权限，这段代码简化了请求权限的代码书写。暂时支持相机、相册、麦克风，其它权限以后再加。

AuthorizationTool.h

//
//  AuthorizationTool.h
//  Rokk
//
//  Created by Jarvis on 01/11/2016.
//  Copyright © 2016 JQTech. All rights reserved.
//

#import <Foundation/Foundation.h>

typedef NS_ENUM(NSUInteger, AuthorizationStatus) {
    AuthorizationStatusAuthorized = 0,    // 已授权
    AuthorizationStatusDenied,            // 拒绝
    AuthorizationStatusRestricted,        // 应用没有相关权限，且当前用户无法改变这个权限，比如:家长控制
    AuthorizationStatusNotSupport         // 硬件等不支持
};

@interface AuthorizationTool : NSObject

/**
 *  请求所有权限（相机、相册、麦克风）
 */
+ (void)requestAllAuthorization;

/**
 *  请求相册访问权限
 *
 *  @param callback <#callback description#>
 */
+ (void)requestImagePickerAuthorization:(void(^)(AuthorizationStatus status))callback;

/**
 *  请求相机权限
 *
 *  @param callback <#callback description#>
 */
+ (void)requestCameraAuthorization:(void(^)(AuthorizationStatus status))callback;

/**
 *  请求麦克风权限
 *
 *  @param callback <#callback description#>
 */
+ (void)requestMicrophoneAuthorization:(void(^)(AuthorizationStatus status))callback;

//+ (void)requestAddressBookAuthorization:(void (^)(AuthorizationStatus))callback;


@end

AuthorizationTool.m

//
//  AuthorizationTool.m
//  Rokk
//
//  Created by Jarvis on 01/11/2016.
//  Copyright © 2016 JQTech. All rights reserved.
//

#import "AuthorizationTool.h"

#import <AssetsLibrary/AssetsLibrary.h>
#import <Photos/Photos.h>

@implementation AuthorizationTool

+ (void)requestAllAuthorization {
    [AuthorizationTool requestCameraAuthorization:^(AuthorizationStatus status) {
        [AuthorizationTool responseAuthorizationStatus:status permissionName:@"Camera"];
    }];
    [AuthorizationTool requestMicrophoneAuthorization:^(AuthorizationStatus status) {
        [AuthorizationTool responseAuthorizationStatus:status permissionName:@"Audio Record"];
    }];
    [AuthorizationTool requestImagePickerAuthorization:^(AuthorizationStatus status) {
        [AuthorizationTool responseAuthorizationStatus:status permissionName:@"Album"];
    }];
}


+ (void)responseAuthorizationStatus:(AuthorizationStatus)status permissionName:(NSString *)name {
    switch (status) {
        case AuthorizationStatusAuthorized:
        {
            NSLog(@"Authorized");
            break;
        }
        case AuthorizationStatusDenied:
        case AuthorizationStatusRestricted:
        {
            UIViewController *rootController = [UIApplication sharedApplication].keyWindow.rootViewController;
            
            NSString *title = [NSString stringWithFormat:@"Please Grant %@ Permission to Rokk in The Settings App", name];
            UIAlertController *authAlert = [UIAlertController alertControllerWithTitle:title message:nil preferredStyle:UIAlertControllerStyleAlert];
            [authAlert addAction: [UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleDefault handler:nil]];
            [authAlert addAction: [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDestructive handler:^(UIAlertAction * _Nonnull action) {
                
                NSURL *settingUrl = [NSURL URLWithString:UIApplicationOpenSettingsURLString];
                if ([[UIApplication sharedApplication] canOpenURL:settingUrl]) {
                    [[UIApplication sharedApplication] openURL:settingUrl];
                }
            }]];
            
            [rootController presentViewController:authAlert animated:YES completion:nil];
            
            break;
        }
        case AuthorizationStatusNotSupport:
        {
            NSLog(@"Device Not Support");
            break;
        }
        default:
            break;
    }
}


#pragma mark - 相册
+ (void)requestImagePickerAuthorization:(void(^)(AuthorizationStatus status))callback {
    if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera] ||
        [UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]) {
        
        ALAuthorizationStatus authStatus = [ALAssetsLibrary authorizationStatus];
        if (authStatus == ALAuthorizationStatusNotDetermined) { // 未授权
            if ([UIDevice currentDevice].systemVersion.floatValue < 8.0) {
                [self executeCallback:callback status:AuthorizationStatusAuthorized];
            } else {
                [PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) {
                    if (status == PHAuthorizationStatusAuthorized) {
                        [self executeCallback:callback status:AuthorizationStatusAuthorized];
                    } else if (status == PHAuthorizationStatusDenied) {
                        [self executeCallback:callback status:AuthorizationStatusDenied];
                    } else if (status == PHAuthorizationStatusRestricted) {
                        [self executeCallback:callback status:AuthorizationStatusRestricted];
                    }
                }];
            }
            
        } else if (authStatus == ALAuthorizationStatusAuthorized) {
            [self executeCallback:callback status:AuthorizationStatusAuthorized];
        } else if (authStatus == ALAuthorizationStatusDenied) {
            [self executeCallback:callback status:AuthorizationStatusDenied];
        } else if (authStatus == ALAuthorizationStatusRestricted) {
            [self executeCallback:callback status:AuthorizationStatusRestricted];
        }
    } else {
        [self executeCallback:callback status:AuthorizationStatusNotSupport];
    }
}

#pragma mark - 相机
+ (void)requestCameraAuthorization:(void (^)(AuthorizationStatus))callback {
    if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
        AVAuthorizationStatus authStatus = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
        if (authStatus == AVAuthorizationStatusNotDetermined) {
            [AVCaptureDevice requestAccessForMediaType:AVMediaTypeVideo completionHandler:^(BOOL granted) {
                if (granted) {
                    [self executeCallback:callback status:AuthorizationStatusAuthorized];
                } else {
                    [self executeCallback:callback status:AuthorizationStatusDenied];
                }
            }];
        } else if (authStatus == AVAuthorizationStatusAuthorized) {
            [self executeCallback:callback status:AuthorizationStatusAuthorized];
        } else if (authStatus == AVAuthorizationStatusDenied) {
            [self executeCallback:callback status:AuthorizationStatusDenied];
        } else if (authStatus == AVAuthorizationStatusRestricted) {
            [self executeCallback:callback status:AuthorizationStatusRestricted];
        }
    } else {
        [self executeCallback:callback status:AuthorizationStatusNotSupport];
    }
}

+ (void)requestMicrophoneAuthorization:(void (^)(AuthorizationStatus))callback {
    AVAudioSession *audioSession = [AVAudioSession sharedInstance];
    AVAudioSessionRecordPermission recordPermission = [audioSession recordPermission];
    switch (recordPermission) {
        case AVAudioSessionRecordPermissionUndetermined:
        {
            [audioSession requestRecordPermission:^(BOOL granted) {
                if (granted) {
                    [self executeCallback:callback status:AuthorizationStatusAuthorized];
                } else {
                    [self executeCallback:callback status:AuthorizationStatusDenied];
                }
            }];
            break;
        }
        case AVAudioSessionRecordPermissionGranted:
            [self executeCallback:callback status:AuthorizationStatusAuthorized];
            break;
        case AVAudioSessionRecordPermissionDenied:
            [self executeCallback:callback status:AuthorizationStatusDenied];
            break;
            
        default:
            [self executeCallback:callback status:AuthorizationStatusNotSupport];
            break;
    }
}


#pragma mark - callback
+ (void)executeCallback:(void (^)(AuthorizationStatus))callback status:(AuthorizationStatus)status {
    dispatch_async(dispatch_get_main_queue(), ^{
        if (callback) {
            callback(status);
        }
    });
}


@end