pmeems
commented
6 years ago I just looked at the C++ code and I don't see anything that could explain this:
void CShapefileCategories::ApplyExpressionCore(long CategoryIndex)
{
if (!_shapefile)
return;
CComPtr<ITable> tbl = NULL;
_shapefile->get_Table(&tbl);
if ( !tbl ) return;
long numShapes;
_shapefile->get_NumShapes(&numShapes);
// vector of numShapes size with category index for each shape
std::vector<int> results;
results.resize(numShapes, -1);
bool uniqueValues = true;
for (unsigned int i = 0; i < _categories.size(); i++) {
tkCategoryValue value;
_categories[i]->get_ValueType(&value);
if (value != cvSingleValue) {
uniqueValues = false;
break;
}
}
// ----------------------------------------------------------------
// we got unique values classification and want to process it fast
// ----------------------------------------------------------------
bool parsingIsNeeded = true;
if (_classificationField != -1 && uniqueValues)
{
parsingIsNeeded = false; // in case there are unique values only we don't need any parsing
std::map<CComVariant, long> myMap; // variant value as key and number of category as result
for (unsigned int i = 0; i < _categories.size(); i++)
{
if (i == CategoryIndex || CategoryIndex == -1 )
{
CComVariant val;
_categories[i]->get_MinValue(&val);
if (val.vt != VT_EMPTY)
{
CComVariant val2;
VariantCopy(&val2, &val);
myMap[val2] = i;
}
}
}
// applying categories to shapes
VARIANT val;
VariantInit(&val);
for (long i = 0; i < numShapes; i++)
{
tbl->get_CellValue(_classificationField, i, &val);
if (myMap.find(val) != myMap.end())
{
results[i] = myMap[val]; // writing the index of category
}
}
VariantClear(&val);
}
// -------------------------------------------------------------
// Analyzing expressions
// -------------------------------------------------------------
if (parsingIsNeeded)
{
// building list of expressions
std::vector<CString> expressions;
for (unsigned int i = 0; i < _categories.size(); i++)
{
if (i == CategoryIndex || CategoryIndex == -1 )
{
CComBSTR expr;
_categories[i]->get_Expression(&expr);
USES_CONVERSION;
CString str = OLE2CA(expr);
expressions.push_back(str);
}
else
{
// we don't need this categories, so dummy strings for them
CString str = "";
expressions.push_back(str);
}
}
// adding category indices for shapes in the results vector
TableHelper::Cast(tbl)->AnalyzeExpressions(expressions, results);
}
// saving results
if (CategoryIndex == -1 )
{
for (unsigned long i = 0; i < results.size(); i++)
{
_shapefile->put_ShapeCategory(i, results[i]);
}
}
else
{
for (unsigned long i = 0; i < results.size(); i++)
{
if (results[i] == CategoryIndex)
_shapefile->put_ShapeCategory(i, CategoryIndex);
}
}
}
I don't have MapWinGIS v4.8 anymore, I'm using v4.9-dev and I'm all up-to-date with Win10.
Perhaps you could try to reinstall MapWinGIS?
You could try to create a small new application in VB.NET (or C#) with 1 form with MapWinGIS and open a shapefile and to the Categories.ApplyExpressions.
When it is not crashing it suggests it is something with MS-Access, if it is still crashing you could share the code and I can have a look.
You could also add a try-catch around the method and log the exception. That might help as well.
IslandHydro
As of yesterday, MapWinGIS started crashing on one pc (my main). I had not changed anything on the pc (although a Windows 10 update happened the same morning....). The exact same code still works on other pc's. The application is a MsAccess database, several forms utilizing MapWinGIS. This code has been working fine for the last 4 or 5 years. I'm running MapWinGIS version 4.8. The line of code that crashes is:
SelWellsLayer.Categories.ApplyExpressions
The .ApplyExpressions function causes crashes in all forms that have that code. When that line of code is run, the database just disappears (closes) without any messages. I'm at a bit of a loss on how to diagnose this. I tried uninstalling and re-installing MapWinGIS, no change. Thoughts?
Thanks, Doug