之前项目当中的接入的高德逆地理编码功能偶尔会出现参数错误的bug，经过排查服务端异常log，发现请求的url中的location参数中的小数点变成了逗号。
代码如下
???????public async Task<MapResult> GetMapResultAsync(double lat, double lng) ???????{ ???????????string url = string.Format("http://restapi.amap.com/v3/geocode/regeo?output=json&location={0},{1}&key={2}", ????????????????lng.ToString(), lat.ToString(), GouldAk); ???????????GolderMapResult res; ???????????try ???????????{ ???????????????string json = await HttpHelper.GetAsync(url); ???????????????json = json.Replace("[]", "\"\""); ???????????????res = JsonConvert.DeserializeObject<GolderMapResult>(json); ???????????????if (res.resultBase.addressComponentBase.city.IsNullOrWhiteSpace()) ???????????????????res.resultBase.addressComponentBase.city = res.resultBase.addressComponentBase.province; ???????????} ???????????catch (Exception ex) ???????????{ ???????????????Logger.Error("请求高德地图失败:" + url); ???????????????throw ex; ???????????} ???????????if (res.status != 1) ???????????{ ???????????????Logger.Error("请求高德地图失败"); ???????????????throw new UserFriendlyException("请求高德地图失败，状态码:" + res.status + " 说明:" + res.info + " url:" + url); ???????????} ???????????????????????????return res; ???????}其中 lng.ToString(), lat.ToString() 转换string的时候，偶尔会把中间的点号转成逗号，于是造成高德api返回参数错误。
后来在网上查找原因，参考这篇博客http://blog.chinaunix.net/uid-9255716-id-107923.html
对于用“.”分隔千位，用“,”分隔小数的国家，1,234.56 将会格式化成 1.234,56。如果您需要结果无论在什么语言下都是一样的，就请使用 CultureInfo.InvariantCulture 作为语言。
接下来就简单了，贴修改后的代码
???????public async Task<MapResult> GetMapResultAsync(double lat, double lng) ???????{ ???????????string url = string.Format("http://restapi.amap.com/v3/geocode/regeo?output=json&location={0},{1}&key={2}", ????????????????lng.ToString(CultureInfo.InvariantCulture), lat.ToString(CultureInfo.InvariantCulture), GouldAk); ???????????GolderMapResult res; ???????????try ???????????{ ???????????????string json = await HttpHelper.GetAsync(url); ???????????????json = json.Replace("[]", "\"\""); ???????????????res = JsonConvert.DeserializeObject<GolderMapResult>(json); ???????????????if (res.resultBase.addressComponentBase.city.IsNullOrWhiteSpace()) ???????????????????res.resultBase.addressComponentBase.city = res.resultBase.addressComponentBase.province; ???????????} ???????????catch (Exception ex) ???????????{ ???????????????Logger.Error("请求高德地图失败:" + url); ???????????????throw ex; ???????????} ???????????if (res.status != 1) ???????????{ ???????????????Logger.Error("请求高德地图失败"); ???????????????throw new UserFriendlyException("请求高德地图失败，状态码:" + res.status + " 说明:" + res.info + " url:" + url); ???????????} ???????????????????????????return res; ???????}只是把 lng.ToString(), lat.ToString() 替换成了 lng.ToString(CultureInfo.InvariantCulture), lat.ToString(CultureInfo.InvariantCulture) ，这样这个bug就解决了。
.net double类型转string类型的坑
原文地址：https://www.cnblogs.com/hucheng/p/10270924.html