/// <summary>
/// 获取SDO_GEOMETRY的SDO_ELEM_INFO(维数组，仅针对简单图形)
/// 说明：SDO_ELEM_INFO（sdo_starting_offset,sdo_etype,sdo_interpretation）
/// SDO_STARTING_OFFSET:声明了组成当前几何片段的第一个坐标在SDO_ORDINATES数组中的坐标序号。坐标序号是从1开始起算的而非从0开始。
/// SDO_ETYPE:声明元素的类型。
/// SDO_ETYPE 值 = 1, 2, 1003,或2003，说明几何为简单的几何类型。可以全部按SDO_ELEM_INFO 属性单元【即三个以逗号隔开的数】来理解sdo_ordinate_array中的坐标序列。
/// 特别说明：SDO_ETYPE 值 = 1003 ，假如几何类型为面，则表示为外多边形环（以逆时针顺序）
/// SDO_ETYPE 值 = 2003 ，假如几何类型为面，则表示为内多边形环（以顺时针顺序）
/// </summary>
/// <param name="gType"></param>
/// <returns></returns>
public static double[] GetElemInfo(sdogeometryTypes.GTYPE gType)
{
double[] arr = new double[3];
//只支持简单类型，arr[0]=1表示SDO_ORDINATES数据第一个值开始是坐标
arr[0] = 1;
double type = System.Convert.ToDouble(gType);
switch (gType)
{
case sdogeometryTypes.GTYPE.POINT:
arr[1] = 1;
arr[2] = 1;
break;
case sdogeometryTypes.GTYPE.LINE:
arr[1] = 2;
arr[2] = 1;
break;
case sdogeometryTypes.GTYPE.POLYGON://外围逆时针，不处理空岛的情况
arr[1] = 1003;
arr[2] = 1;
break;
case sdogeometryTypes.GTYPE.UNKNOWN_GEOMETRY:
arr[1] = 0;
arr[2] = -999;
break;
default:
arr[1] = 1;
arr[2] = 1;
break;
}
return arr;
}
/// <summary>
/// 根据SDOORDINATE坐标数组构建WKT格式的坐标串
/// </summary>
/// <param name="sdoOrdinate"></param>
/// <returns></returns>
public static string GetWKTFromSdoOrdinate(double[] sdoOrdinate,sdogeometryTypes.GTYPE gType)
{
string ordinateStr = string.Empty;
ordinateStr = sdoOrdinate[0].ToString();
for (int i = 1; i < sdoOrdinate.Length; i++)
{
ordinateStr += "," + sdoOrdinate[i];
}
if (gType == sdogeometryTypes.GTYPE.POINT)
{
if (sdoOrdinate.Length != 2)
{
throw new ArgumentNullException("点图形坐标数目不正确。");
}
ordinateStr = "Point(" + sdoOrdinate[0].ToString() + " " + sdoOrdinate[1].ToString() + ")";
}
else if (gType == sdogeometryTypes.GTYPE.LINE)
{
if (sdoOrdinate.Length < 4)
{
throw new ArgumentNullException("线图形坐标数目不正确。");
}
ordinateStr = "LINESTRING (";
for (int i = 0; i < sdoOrdinate.Length; i++)
{
if (i % 2 == 0)//偶数：0,2，4,6……
{
ordinateStr += sdoOrdinate[i] + " ";
}
else if (i % 2 == 1)//奇数：1,，35,7……
{
ordinateStr += sdoOrdinate[i] + ",";
}
}
ordinateStr += ")";
}
else if (gType == sdogeometryTypes.GTYPE.POLYGON)
{
if (sdoOrdinate.Length < 6)
{
throw new ArgumentNullException("面图形坐标数目不正确。");
}
ordinateStr = "POLYGON ((";
for (int i = 0; i < sdoOrdinate.Length; i++)
{
if (i % 2 == 0)//偶数：0,2，4,6……
{
ordinateStr += sdoOrdinate[i] + " ";
}
else if (i % 2 == 1)//奇数：1,，35,7……
{
ordinateStr += sdoOrdinate[i] + ",";
}
}
ordinateStr += "))";
}
return ordinateStr;
}
