/// <summary>
/// The test file manager.
/// </summary>
private static void TestFileManager()
{
string sql = "SELECT * FROM Buildings WHERE gid < 50";
int handle = Map.AddLayerFromDatabase(CONNECTION_STRING, sql, true);
if (handle == -1)
{
Debug.Print("Failed to open layer: " + Map.FileManager.get_ErrorMsg(Map.FileManager.LastErrorCode));
// in case the reason of failure is still unclear, let's ask GDAL for details
var gs = new GlobalSettings();
Debug.Print("Last GDAL error: " + gs.GdalLastErrorMsg);
}
else
{
OgrLayer l = Map.get_OgrLayer(handle);
if (l != null)
{
Debug.Print("Number of features: " + l.FeatureCount);
// now access the data
Shapefile sf = l.GetBuffer();
Debug.Print("Number of shapes: " + sf.NumShapes);
}
}
}
/// <summary>
/// The display underlying data.
/// </summary>
private static void DisplayUnderlyingData()
{
string layerName = "fields";
var layer = new OgrLayer();
if (layer.OpenFromDatabase(CONNECTION_STRING, layerName, false))
{
// let's frist try to extract some info without loading the data locally
Extents ext = null;
if (layer.get_Extents(out ext))
{
Debug.WriteLine("Extents w/o loading the data: " + ext.ToDebugString());
}
Debug.WriteLine("Feature count: " + layer.FeatureCount);
// now load the data locally and display the same info
Shapefile shapefile = layer.GetBuffer();
if (shapefile != null)
{
Debug.WriteLine("Extents from the loaded data: " + shapefile.Extents.ToDebugString());
Debug.WriteLine("Shape count: " + shapefile.NumShapes);
Debug.WriteLine("Layer fields: ");
for (int i = 0; i < shapefile.NumFields; i++)
{
Debug.WriteLine(shapefile.get_Field(i).Name);
}
}
}
}
public void ReadAttributesFromPostGISLayer()
{
var ogrDatasource = new OgrDatasource();
try
{
var result = ogrDatasource.Open("PG:host=127.0.0.1 port=5432 dbname=mw_test user=mapwindow password=test123");
Assert.IsTrue(result, "Cannot open PostGIS Connectie: " + ogrDatasource.GdalLastErrorMsg);
Assert.IsTrue(ogrDatasource.LayerCount > 1, "No layers found");
OgrLayer attributeLayer = null;
for (var i = 0; i < ogrDatasource.LayerCount; i++)
{
var layer = ogrDatasource.GetLayer(i);
Console.WriteLine(layer.Name);
if (layer.Name == "attributes")
{
attributeLayer = layer;
}
}
Assert.IsNotNull(attributeLayer, "Couldn't find the attribute layer");
Console.WriteLine("Working with attributes layer");
var sf = attributeLayer.GetBuffer();
Assert.IsNotNull(sf, "Could not get buffer");
var numShapes = sf.NumShapes;
Assert.AreEqual(3, numShapes);
var numFields = sf.NumFields;
Assert.IsTrue(numFields > 0, "No fields found");
var fidColumn = attributeLayer.FIDColumnName;
Console.WriteLine("fidColumn: " + fidColumn);
// First shape has all attributes filled:
Console.WriteLine("Testing first shape, all filled");
for (var fieldIndex = 0; fieldIndex < numFields; fieldIndex++)
{
var value = sf.CellValue[fieldIndex, 0];
Console.WriteLine($"{sf.Field[fieldIndex].Name}: {value}");
Assert.IsNotNull(value, $"{sf.Field[fieldIndex].Name} should not be null");
}
// Second shape has only the geometry filled and the rest default values (which should be NULL):
Console.WriteLine("Testing second shape, default values");
var numNonNulls = 0;
for (var fieldIndex = 0; fieldIndex < numFields; fieldIndex++)
{
var value = sf.CellValue[fieldIndex, 1];
Console.WriteLine($"{sf.Field[fieldIndex].Name}: {value}");
// Skip FID because it always has a value:
if (sf.Field[fieldIndex].Name == fidColumn)
{
continue;
}
if (value != null)
{
numNonNulls++;
}
}
if (numNonNulls > 0)
{
// No assert, need to check the third shape as well:
Console.WriteLine($"Error! Second shape has {numNonNulls} non NULL fields!");
}
// Third shape has all fields explicitly NULL:
Console.WriteLine("Testing third shape, all null");
numNonNulls = 0;
for (var fieldIndex = 0; fieldIndex < numFields; fieldIndex++)
{
var value = sf.CellValue[fieldIndex, 2];
Console.WriteLine($"{sf.Field[fieldIndex].Name}: {value}");
// Skip FID because it always has a value:
if (sf.Field[fieldIndex].Name == fidColumn)
{
continue;
}
if (value != null)
{
numNonNulls++;
}
}
Assert.AreEqual(0, numNonNulls, $"Third shape has {numNonNulls} non NULL fields!");
}
finally
{
ogrDatasource.Close();
}
}
/// <summary>
/// The test edit layer.
/// </summary>
/// <returns>
/// The <see cref="bool" />.
/// </returns>
private static bool TestEditLayer()
{
var layer = new OgrLayer();
layer.GlobalCallback = form;
if (!layer.OpenFromDatabase(CONNECTION_STRING, "buildings", true))
{
Debug.Print("Failed to open layer: " + layer.get_ErrorMsg(layer.LastErrorCode));
return(false);
}
// check if editing is supported for driver
Debug.Print("Driver supports editing: " + layer.TestCapability(tkOgrLayerCapability.olcRandomWrite));
// now check if we can actually do it, as there can be other limitations
if (!layer.get_SupportsEditing(tkOgrSaveType.ostSaveAll))
{
Debug.Print("Can't edit a layer: " + layer.get_ErrorMsg(layer.LastErrorCode));
layer.Close();
return(false);
}
Shapefile sf = layer.GetBuffer();
if (sf != null)
{
// possible types of editing
bool editValue = true;
bool addShape = true;
bool editShape = true;
bool removeShape = true;
if (editValue)
{
int shapeIndex = 0;
int fieldIndex = 2;
object val = sf.get_CellValue(fieldIndex, shapeIndex);
sf.EditCellValue(fieldIndex, shapeIndex, "test_writing");
// this flag will notify the driver that changes should saved back to source
sf.ShapeModified[shapeIndex] = true;
}
if (addShape)
{
int shapeIndex = sf.NumShapes;
Shape shp = sf.get_Shape(0);
shp = shp.Buffer(1, 50);
// modified flag is set automatically in this case
bool result = sf.EditInsertShape(shp, ref shapeIndex);
Debug.Print("Shape was inserted: " + result);
}
if (editShape)
{
// since shapefile is in in-memory mode, geometry of shapes can be changed directly;
// bear in mind that this won't work for file-based shapefiles, in that case get_Shape will
// populate Shape object which will have no futher link with parent shapefile
Shape shp = sf.get_Shape(sf.NumShapes - 1);
for (int i = 0; i < shp.numPoints; i++)
{
double x = 0.0, y = 0.0;
if (shp.get_XY(i, ref x, ref y))
{
shp.put_XY(i, x + 0.01, y + 0.01); // let's move it a little
}
}
}
if (removeShape)
{
bool result = sf.EditDeleteShape(sf.NumShapes - 1);
Debug.Print("Shape was deleted: " + result);
}
// saving it
int count;
tkOgrSaveResult saveResults = layer.SaveChanges(out count);
Debug.Print("Save result: " + saveResults);
Debug.Print("Number of shapes saved: " + count);
// displaying info on errors
for (int i = 0; i < layer.UpdateSourceErrorCount; i++)
{
Debug.Print(
"Error for shape id {0}: {1}",
layer.UpdateSourceErrorShapeIndex[i],
layer.UpdateSourceErrorMsg[i]);
}
return(true);
}
layer.Close();
return(false);
}
