一  调用方法一

1.1 Unity代码-Unity调方法传参,有返回值

[DllImport("__Internal")]
// 给iOS传string参数,有返回值,返回值通过iOS的return方法返回给Unity
private static extern string getIPv6(string mHost, string mPort)

1.2 iOS代码-iOS通过return方法,将值返回给Unity

/**获取IPv6的值,并返回给Unity@param mHost 主机名@param mPort 端口号@return IPv6值
*/
extern "C" const char * getIPv6(const char *mHost, const char *mPort)
{return mHost;
}

1.3 注意空间分配（上面的写法会报如下错误）

skins(2509,0x1a8e5cb40) malloc: *** error for object 0x16fdc9114: pointer being freed was not allocated
*** set a breakpoint in malloc_error_break to debug

1.4 修改错误后正确代码

/**获取IPv6的值,并返回给Unity@param mHost 主机名@param mPort 端口号@return IPv6值
*/
extern "C" const char * getIPv6(const char *mHost, const char *mPort)
{// strdup(const char *__s1) 复制mHost字符串,通过Malloc()进行空间分配 return strdup(mHost);
}

1.5 如果Unity传参为int类型,可以使用return mHost方法

unity代码

[DllImport("__Internal")]
// 给iOS传int参数,无返回值,返回值通过iOS的return方法返回给Unity
private static extern int setMyInt(int date);

ios代码

// 返回int值
extern "C" int setMyInt(int date)
{return date;
}

1.5 总结

1：如果Unity传参为string类型,不执行strdup()方法而使用return mHost方法,导致mHost没有分配内存空间而报错

2：Unity方法中参数的变量名为date,在iOS中的extern “C” int setMyInt(int date)方法中设置的参数变量名可以与Unity的相同,设置为date,也可以是a、b、c等自定义参数变量,但是为了代码规范,尽量和Unity参数保持一致.

3：调用DllImport(“”)方法,需要引入命名空间:
using System.Runtime.InteropServices;

4：extern “C”修饰的变量和函数是按照C语言方式编译和连接的

二 Unity调方法传参,无返回值

2.1 unity代码

// 传数据给iOS
[DllImport("__Internal")]
// 给iOS传string参数,无返回值,返回值通过iOS的UnitySendMessage方法返回给Unity
private static extern void setDate(string date);// 接收iOS的数据
public void GetDate(string date)
{
}

2.2 ios代码

/**返回Unity日期@param date 日期@return 无返回值*/
extern "C" void setDate(const char *date)
{/**发送数据给Unity@param obj 模型名@param method Unity接收iOS数据的方法名@param msg 传给Unity的数据UnitySendMessage(const char* obj, const char* method, const char* msg);*/UnitySendMessage("PublicGameObject", "GetDate", date);
}

2.3 

iOS通过UnitySendMessage方法返回数据给Unity时,需要传正确的date值,如果UnitySendMessage方法中的第三个参数不是将date作为参数,而是自定义的NSString类,需要做类型转换(Unity中的字符串为string,OC中的字符串为NSString)如下代码

extern "C" void setDate(const char *date)
{NSString *dateStr = @"Hello Word";UnitySendMessage("PublicGameObject", "GetDate", [dateStr UTF8String]);
}

三 完整代码

3.1 ios 代码

//
//  UserAgent.m
//  UnityFramework
//
//  Created by lxj on 2024/3/25.
//#import "UserAgent.h"
#import <WebKit/WebKit.h>
#import "SensorsAnalyticsSDK.h"
#pragma mark - Unity 回调函数
//初始化回调
static void(*GetUserAgentCallback)(const char *);@implementation UserAgent#pragma mark - 供Unity调用的函数接口
#if defined(__cplusplus)
extern "C"{
#endifvoid getUA(void(*getUserAgentCallback)(const char *)){GetUserAgentCallback = getUserAgentCallback;[[UserAgent GetInstance] GetUserUIWebViewAgent];}const char *  getAnonymousId(){const char * anonymousId = [[[SensorsAnalyticsSDK sharedInstance] anonymousId] UTF8String];return strdup(anonymousId);}const char *  getDistinctId(){const char * distinctId = [[[SensorsAnalyticsSDK sharedInstance] distinctId] UTF8String];return strdup(distinctId);}#if defined(__cplusplus)
}
#endif-(void)GetUserUIWebViewAgent{WKWebView *webView = [[WKWebView alloc] initWithFrame:CGRectZero];NSString * result =  [webView valueForKey:@"userAgent"];if(GetUserAgentCallback){GetUserAgentCallback([result UTF8String]);NSLog(@"iOS 获取到的当前设备的userAgent为 ===%@",result);GetUserAgentCallback = nil;}
}UserAgent* instanceUA = nil;+(UserAgent*)GetInstance
{NSLog(@"DoInit");if(instanceUA == nil){instanceUA = [[UserAgent alloc] init];}return instanceUA;
}@end

3.2 unity代码

#if UNITY_IOS
using System;
using System.Runtime.InteropServices;
using AOT;
using Bao.Debug;
using Bao.Stage;
using UnityEngine;namespace Code.SDK.DeviceId.iOS {public class IOSDeviceIdClient: IDeviceIdClient {protected static Action<string> GetUAResultCallback; private const string INTERNAME_NAME = "__Internal";[DllImport(INTERNAME_NAME, CallingConvention = CallingConvention.Cdecl)]private static extern void getUA(GetUACallbackDelegate callback);[DllImport(INTERNAME_NAME, CallingConvention = CallingConvention.Cdecl)]private static extern string getAnonymousId();[DllImport(INTERNAME_NAME, CallingConvention = CallingConvention.Cdecl)]private static extern string getDistinctId();public void GetOAID(Action<string> callback) {callback?.Invoke(null);}public void GetUA(Action<string> callback){var ua = PlayerPrefs.GetString(DeviceIdConstants.KEY_ATTRIBUTE_UA);LogFile.get.Log("ios本地存储UA值为 == " + ua);if (string.IsNullOrEmpty(ua)){GetUAResultCallback = callback;getUA(GetUACallback);}else{callback?.Invoke(ua);}}/// <summary>/// getUA/// </summary>private delegate void GetUACallbackDelegate(string ua);/// <summary>/// getUA回调/// </summary>/// <param name="ua"></param>[MonoPInvokeCallback(typeof(GetUACallbackDelegate))]private static void GetUACallback(string ua){LogFile.get.Log("ios从原生获取UA值为 == " + ua);PlayerPrefs.SetString(DeviceIdConstants.KEY_ATTRIBUTE_UA, ua);PlayerPrefs.Save();if (GetUAResultCallback != null){GetUAResultCallback(ua);GetUAResultCallback = null;}}public string GetAndroidId() {return null;}public string GetAnonymousId() {string anonymousId = getAnonymousId();LogFile.get.Log("ios神策设备id == " + anonymousId);return anonymousId;}public string GetDistinctId(){string distinctId = getDistinctId();LogFile.get.Log("ios神神策id == " + distinctId);return distinctId;}}
}
#endif