离线地图开发:google地图坐标和百度地图的相互转化

		jQuery.MapConvert = {
			x_pi : 3.14159265358979324 * 3000.0 / 180.0,
			/// <summary>
			/// 中国正常坐标系GCJ02协议的坐标，转到 百度地图对应的 BD09 协议坐标
			///  point 为传入的对象，例如{lat:xxxxx,lng:xxxxx}
            /// google地图坐标转换成百度地图坐标
			/// </summary>
			Convert_GCJ02_To_BD09 : function(point) {
				var x = point.lng, y = point.lat;
				var z = Math.sqrt(x * x + y * y) + 0.00002
						* Math.sin(y * jQuery.MapConvert.x_pi);
				var theta = Math.atan2(y, x) + 0.000003
						* Math.cos(x * jQuery.MapConvert.x_pi);
				point.lng = z * Math.cos(theta) + 0.0065;
				point.lat = z * Math.sin(theta) + 0.006;
			},
			/// <summary>
			/// 百度地图对应的 BD09 协议坐标，转到 中国正常坐标系GCJ02协议的坐标
            /// 百度地图坐标转换成google地图坐标
			/// </summary>
			Convert_BD09_To_GCJ02 : function(point) {
				var x = point.lng - 0.0065, y = point.lat - 0.006;
				var z = Math.sqrt(x * x + y * y) - 0.00002
						* Math.sin(y * jQuery.MapConvert.x_pi);
				var theta = Math.atan2(y, x) - 0.000003
						* Math.cos(x * jQuery.MapConvert.x_pi);
				point.lng = z * Math.cos(theta);
				point.lat = z * Math.sin(theta);
			}
		}