Show DBF values above Mapwingis + Delphi points

Question

I have the following code to open a file . shp and plot it on a component of MapWinGis Map1.

procedure TForm1.Button1Click(Sender: TObject);
 var shp: Shapefile;
 HandleLayer: integer;
begin
  shp:= CoShapefile.Create;
  shp.Open ('C:\Users\Documents\BD Demo\Alta Cruz\cruz\alta_cruz.shp', nil) ;
  Map1.Focused;
  HandleLayer:= Map1.AddLayer (shp, true);
  Map1.ZoomToMaxExtents;

And a very similar code to open the stitch file:

procedure TForm1.Button2Click(Sender: TObject);
 var shp: Shapefile;
 HandleLayer: integer;
begin
  shp:= CoShapefile.Create;
  shp.Open ('C:\Users\Desktop\opa\Win32\Debug\Amostragem.shp', nil) ;
  Map1.Focused;
  HandleLayer:= Map1.AddLayer (shp, true);
  Map1.ZoomToMaxExtents;
  shp.StartEditingShapes(true, null);

and as a result I have it:

what I needed was to read the . dbf File from the sample file, and display the points as in the example below:

The example above was made the gis; QGIS

it is possible to do the same?

Answer 1

I do not know this area of yours and also did not work with Mapwingis.

To open a DBF file (Foxpro Data File), you need to create a connection to that database.

You can use the Tadoconnection component, and the Connection String (Connectionstring)= "Driver={Microsoft dbase Driver (*. dbf)};Driverid=277;Dbq=c: mydbpath;" where mydbpath is the path to the folder where your DBF file is. Type what you used in . open('). Also change the Loginprompt property to False.

To read the DFB file, you will need a component, Tadoquery, to set in the Connection property the Tadoconnection you added earlier. Set the following query in the SQL property:

Select * from <arquivodbf>

To be able to read all the contents of the file you can use the following code (See the notes after the code):

ADOConnection1.Connected:= True;
ADOQuery1.Open;
while not ADOQuery1.Eof do
  begin
  memo1.Lines.Add(ADOQuery1.FieldByName('Codigo').Value);
  ADOQuery1.Next;
end;
ADOQuery1.Close;
ADOConnection1.Connected:= False;

Comments: Adoconnection1 is my Tadoconnection Adoquery1 is the Tadoquery memo1 is the place where I am throwing the value I read in the fields, you must adapt your need.

I’ve worked a lot with DBF files, in case you need, we’ll talk and change the answer until you solve your problem.

Hugs!

God Bless Us!