android
1.需要权限

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
原文：https://blog.csdn.net/kyn27500/article/details/82116590 

//保存文件到指定路径
    public static String saveImageToGallery(Context context, String bmpPath) {
        // 
        File imgFile = new File(bmpPath);
        if (!imgFile.exists()) {
            return "fail";
        }
        //插入图片到系统相册        
        try {
            MediaStore.Images.Media.insertImage(context.getContentResolver(), bmpPath, "分享图片", "茶馆分享图片");
            //保存图片后发送广播通知更新数据库
            Uri uri = Uri.parse(bmpPath);
            context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, uri));
            return "success";
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return "fail";
    }
原文：https://blog.csdn.net/kyn27500/article/details/82116590 

iOS 
1.需要配置ios  info.plist
<key>NSPhotoLibraryAddUsageDescription</key>
<string>是否允许此APP保存图片到相册？</string>
<key>NSPhotoLibraryUsageDescription</key>
<string>此 App 需要您的同意才能读取媒体资料库</string>
2.包含的头文件：
#import <Photos/Photos.h>
#import<AssetsLibrary/AssetsLibrary.h>
3.包含相应的类库：
Photos.framework
AssetsLibrary.framework
MODULE_METHOD_FUN(SysModule::saveImageToGallery)
    {
        _funcCB = func;
        char*p=(char*)args.data();
        NSString *nsMessage= [[NSString alloc] initWithCString:p encoding:NSUTF8StringEncoding];
        NSURL *url = [NSURL fileURLWithPath:nsMessage];
        __block NSString *assetId = nil;
        
        ALAuthorizationStatus author = [ALAssetsLibrary authorizationStatus];
        if (author ==kCLAuthorizationStatusRestricted || author ==kCLAuthorizationStatusDenied){
            //无权限 引导去开启
            NSURL *url = [NSURL URLWithString:UIApplicationOpenSettingsURLString];
            if ([[UIApplication sharedApplication] canOpenURL:url]) {
                [[UIApplication sharedApplication] openURL:url];
            }
        }else{
            // 1. 存储图片到"相机胶卷"
            [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{ // 这个block里保存一些"修改"性质的代码
                // 新建一个PHAssetCreationRequest对象, 保存图片到"相机胶卷"
                // 返回PHAsset(图片)的字符串标识
                PHAssetChangeRequest *createAssetRequest = [PHAssetChangeRequest creationRequestForAssetFromImageAtFileURL:url];
                assetId = createAssetRequest.placeholderForCreatedAsset.localIdentifier;
            } completionHandler:^(BOOL success, NSError * _Nullable error) {
                if (error) {
                    NSLog(@"保存图片到相机胶卷中失败");
                    CallBack("fail","保存图片到相机胶卷中失败");
                    
                }else{
                    NSLog(@"成功保存图片到相机胶卷中");
                    CallBack("success","成功保存图片到相机胶卷中");
                }
            }];
        }
        
        return "hasFunc";
    }
---------------------  
原文：https://blog.csdn.net/kyn27500/article/details/82116590