c#封装百度web服务geocoding api 、百度坐标转换示例

1、创建基础参数类

    public static class BaiduErrorMessages
    {
        public const string NotKey = "密钥不存在";
        public const string LackParam = "缺少必要请求参数";
    }
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2、定义API错误信息与产品信息

    public enum Status
    {
        /// <summary>
        /// 正常   
        /// </summary>
        Ok = 0,
        /// <summary>
        /// 请求参数非法   
        /// </summary>
        ParameterInvalid = 2,
        /// <summary>
        /// 权限校验失败
        /// </summary>
        VerifyFailure = 3,
        /// <summary>
        /// 配额校验失败
        /// </summary>
        QuotaFailure = 4,
        /// <summary>
        /// 不存在或者非法   
        /// </summary>
        AkFailure = 5,
        /// <summary>
        /// Transform 内部错误
        /// </summary>
        InternalError = 1,
        /// <summary>
        /// from非法
        /// </summary>
        FromIllegal = 21,
        /// <summary>
        /// to非法
        /// </summary>
        ToIllegal = 22,
        /// <summary>
        /// coords非法
        /// </summary>
        CoordsIllegal = 24,
        /// <summary>
        /// coords个数非法，超过限制
        /// </summary>       
        CoordsCountIllegal = 25

    }
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3、定义API结果返回实体映射类

        /// <summary>
        /// 返回结果状态值， 成功返回0，其他值请查看附录。
        /// </summary>
        [JsonProperty(PropertyName = "result")]
        public BaiduGeocodingResult Result;
    }

    public class BaiduGeocodingResult
    {
        /// <summary>
        /// 经纬度坐标
        /// </summary>
        [JsonProperty(PropertyName = "location")]
        public BaiduGeocodingLoaction Location;
        /// <summary>
        /// 位置的附加信息，是否精确查找。1为精确查找，0为不精确。
        /// </summary>
        [JsonProperty(PropertyName = "precise")]
        public int Precise;
        /// <summary>
        /// 可信度
        /// </summary>
        [JsonProperty(PropertyName = "confidence")]
        public int Confidence;
        /// <summary>
        /// 地址类型
        /// </summary>
        [JsonProperty(PropertyName = "level")]
     &