ArcEngine下投影座標和經緯度座標的相互轉換

投影轉經緯度

private IPoint PRJtoGCS( double x, double y)
{
    IPoint pPoint = new PointClass();
    pPoint.PutCoords(x, y);
    ISpatialReferenceFactory pSRF = new SpatialReferenceEnvironmentClass();
    pPoint.SpatialReference = pSRF.CreateProjectedCoordinateSystem( 2414 );
pPoint.Project(pSRF.CreateGeographicCoordinateSystem(( int )esriSRGeoCSType.esriSRGeoCS_Beijing1954));
    return pPoint;
}

 

其中，pPoint.SpatialReference = pSRF.CreateProjectedCoordinateSystem( 2414 );

這行程式碼是設定pPoint 的空間參考，也就是要轉化的點的投影座標。如果不知道投影座標的話，轉化會報異常。

2414 為該投影的enum 值

pPoint.Project(pSRF.CreateGeographicCoordinateSystem(( int )esriSRGeoCSType.esriSRGeoCS_Beijing1954));
將該點的投影座標轉化為經緯度。

 

經緯度到投影：

private IPoint GCStoPRJ(IPoint pPoint, int GCSType, int PRJType)
{
    ISpatialReferenceFactory pSRF = new SpatialReferenceEnvironmentClass();
    pPoint.SpatialReference = pSRF.CreateGeographicCoordinateSystem(GCSType);
    pPoint.Project(pSRF.CreateProjectedCoordinateSystem(PRJType));
    return pPoint;
}