Draw MAPX map from the database
Topic: Mapx Delphi Database Map Layer Style Font
This article will take you from the database to draw in Mapx.
1. Establish the following table for storage coordinates in the database:
ID integer // unique number
Name string // Name (label)
X float // map coordinate x
Y float // map coordinate y
Suppose this table is named xUnit
2, edit the Mapx map, add a new Layer, define you want to add a layer display style in the future, then set this layer is not visible, can not be editable, this layer name is assumed to be "Enterprise Unit".
3. Add a MAPX control in your program, named MAP1
4. Add BDE or ADO components to your database and connect to your database, assume that you add Adoconnection1 and Adotable1 and set their related properties to all content in the above table.
5, add the button and add the Click time code in the button as follows:
Procedure TFORM1.BUTTON1CLICK (Sender: TOBJECT);
VAR
Lyr: layer; //
FTS: feature; // characteristics
PT: Point; //
MStyle: style; // style
Str: string; // Feature label
X, Y: Double;
Begin
Lyr: = map1.layers.createLayer ('Tempanimate', EmptyParam, 1, EmptyParam, EmptyParam);
// Create a Layer in Map1
Map1.Layers.AnimationLayer: = lyr; // Set to the current layer
lyr.editable: = true; // Edit
PT: = Copoint.create;
MStyle: = COSTYLE.CREATE;
mstyle: = map1.Layers.Item ('Enterprise Unit') .allfeatures.Item (1) .style; // Get the characteristics store stored in the layer "Enterprise Unit"
Lyr.Style: = Map1.Layers.Item ('Enterprise Co., Ltd.). Style; //
Lyr.labelproperties.Style: = map1.Layers.Item ('Enterprise ") .Labelproperties.Style; // Label Style
ADOTABLE1.FIRST;
While not adotable1.eof do
Begin
X: = adotable1.fieldbyName ('x'). Asfloat;
Y: = adotable1.fieldbyname ('y'). asfloat;
Str: = adotable1.fieldbyname ('name'). asstring;
Pt.set_ (x, y);
FTS: = Map1.FeatureFactory.createSymbol (PT, MStyle); // Create Features
fts.keyvalue: = Str; // Task
Lyr.addfeature (fts, emptyparam); // Add feature to layer
ADOTABLE1.NEXT;
END;
lyr.autolabel: = true; // automatic label
Lyr.visible: = true; // visible
Lyr.zoommin: = 0; // Zoom range
Lyr.Zoommax: = 77;
END;
6. Follow the steps we can directly express the data in the database, of course, we just show the feature points, there is no other things such as those areas, other things should be, but I can't use it, haha. . E-mail:
Yangyutian@hotmail.com
April 15, 2004
