I’m working on a project that uses MapWinGIS, and I’m trying to transform latitude and longitude into X and Y coordinates using the Transform function, but for some reason it keeps returning false. I am passing double data type arguments to both parameters x and y, just like the documentation requires.
I can’t debug and see why it’s failing so I was wondering if anyone has had this issue before, or could point me in the right direction as to why the method call is returning false.
Thanks for such a quick reply. Yes, the function is calling StartTransform prior to calling Transform:
bool tester2 = gpFROM.StartTransform(gpTO);
Here is the complete method being called when the user clicks that Convert button:
private void button5_Click(object sender, EventArgs e)
{
double lonX, latY;
//int tester;
var gpFROM = new GeoProjection();
var gpTO = new GeoProjection();
int code;
int code2;
// one of the following methods can be used; see more in GeoProjection class
// - use projections provided by MapWinGIS enumerations:
//see what projection is currently selected
string[] wordsTO;
wordsTO = comboBoxTo.Text.Split('=');
code = int.Parse(wordsTO[1]);
string[] wordsFROM;
wordsFROM = comboBoxFROM.Text.Split('=');
code2 = int.Parse(wordsFROM[1]);
//gp.SetWgs84Projection(code);
// check to see if left characters are "LL_"
//If so, it's a coordinate system
if (wordsTO[0].Substring(0, 3) == "LL_")
{
if (code == 4269)
{
//std gpTO.SetWellKnownGeogCS(tkCoordinateSystem.csNAD83);
bool tester4 = gpTO.ImportFromEPSG(code);
}
else if (code == 4267)
{
//std gpTO.SetWellKnownGeogCS(tkCoordinateSystem.csNAD83);
bool tester4 = gpTO.ImportFromEPSG(code);
}
else //default case is WGS84...
{
//gpTO.SetWellKnownGeogCS(tkCoordinateSystem.csWGS_84);
bool tester4 = gpTO.ImportFromEPSG(code);
}
}
else
{
bool tester4 = gpTO.ImportFromEPSG(code);
}
if (wordsFROM[0].Substring(0, 3) == "LL_")
{
if (code2 == 4269)
{
//std gpFROM.SetWellKnownGeogCS(tkCoordinateSystem.csNAD83);
bool tester3 = gpFROM.ImportFromEPSG(code2);
}
else if (code2 == 4267)
{
//std gpFROM.SetWellKnownGeogCS(tkCoordinateSystem.csNAD83);
bool tester3 = gpFROM.ImportFromEPSG(code2);
}
else //default case is WGS84...
{
//std gpFROM.SetWellKnownGeogCS(tkCoordinateSystem.csWGS_84);
bool tester3 = gpFROM.ImportFromEPSG(code2);
}
}
else
{
bool tester3 = gpFROM.ImportFromEPSG(code2);
}
//gpFROM.ImportFromEPSG(code);
// assume this one is LL_
//gpTO.ImportFromEPSG(code2);
//gpTO.SetWellKnownGeogCS(code2);
bool tester2 = gpFROM.StartTransform(gpTO);
//axMap2.GeoProjection = gpFROM;
//string testname;
//testname = gp.Name;
//DataTable dt = new DataTable();
//dt = (DataTable)(dataGridView1.DataSource);
int colX = 0;
int colY = 1;
//find these two first...
string testnameX;
testnameX = comboBoxFromX.Text.ToString();
if (testnameX.Length != 0) //The user has selected something, but not sure if it exists
{
colX = existsvarname(testnameX);
}
string testnameY;
testnameY = comboBoxFromY.Text.ToString();
if (testnameY.Length != 0) //The user has selected something, but not sure if it exists
{
colY = existsvarname(testnameY);
}
string myvalue;
//double eastX = 0;
//double northY = 0;
int newXindex;
int newYindex;
int landingcolumnX = -1;
int landingcolumnY = -1;
string defaultnameX = "LonDD";
string defaultnameY = "LatDD";
testnameX = comboBoxToX.Text.ToString();
if (testnameX.Length != 0) //The user has selected something, but not sure if it exists
{
landingcolumnX = existsvarname(testnameX);
defaultnameX = testnameX;
}
testnameY = comboBoxToY.Text.ToString();
if (testnameY.Length != 0)
{
landingcolumnY = existsvarname(testnameY);
defaultnameY = testnameY;
}
if (landingcolumnX != -1 | landingcolumnY != -1) //The X or Y columns don't exist
{
newXindex = landingcolumnX;
newYindex = landingcolumnY;
}
else
{
dt.Columns.Add(defaultnameX, typeof(double));
dt.Columns.Add(defaultnameY, typeof(double));
newXindex = dt.Columns.IndexOf(defaultnameX);
newYindex = dt.Columns.IndexOf(defaultnameY);
}
if (colX > -1 & colY > -1)
{
for (int i = 0; i < (dataGridView1.RowCount - 1); i++)
{
myvalue = dt.Rows[i][colX].ToString();
lonX = double.Parse(myvalue);
myvalue = dt.Rows[i][colY].ToString();
latY = double.Parse(myvalue);
if (gpFROM.Transform(ref lonX, ref latY))
{
//conversion was successful...
//tester = 1;
dt.Rows[i][newXindex] = lonX.ToString("F9");
dt.Rows[i][newYindex] = latY.ToString("F9");
}
}
}
dataGridView1.EndEdit();
dataGridView1.Refresh();
gpFROM.StopTransform();
updateboxes();
}
Basically what’s happening is the user is loading a csv file without X and Y columns so they need to convert latitude and longitude into X and Y coordinates.
To be more accurate, we use MapWinGIS to convert from Lat-Lon to UTM Northing and Easting, or (2) to convert from UTM Northing and Easting into Lat-Lon.
What is weird is that this same code works correctly on the development environment of the previous developer that worked on this project. He suggested me to check if I have a registered version of MapWinGIS on my pc. He said it was quite the process to get installed properly and I for sure don’t recall the installation being such a complicated task. I might have done something wrong or not have completed the setup correctly.
How can I check if my version is registered? How do I get a registered version?
Hi Jerry,
I’m still working on this issue, and I have some more findings. As you mentioned and after some more digging, I found out that my issue is really with StartTransform, and not Transform. Here’s my GeoProjection target object after the code calls StartTransform:
The target GeoProjection gets declared, it then calls ImportFromEPSG passing a code, I get true as a response, and then calls StartTransform, which is failing returning false. I’m assuming that’s why the object has IsEmpty as true. I did notice that I got a “1806” for LastErrorCode. Any idea what the code could be?
I also saw that I have the option for inspecting the native object, but Native View is throwing an error. How can I enable native code debugging?
