10 examples of mapxtreme practical skills and source code

1. Set the optional layer status.
/**////
/// Change the selectable status of the layer
///

///

///
Public bool layerselectablestatusupdate (string tablealias, bool selectablestatus)
{
If (mapcontrol1.map. Layers [tablealias] = NULL)
Return false;

MapInfo. Mapping. layerhelper. setselectable (mapcontrol1.map. Layers [tablealias], selectablestatu

S );
Return true;
}

2. Set the available status of the layer

/**////

/// Change the available status of the layer to status
///

///

///

Public void layerenablestatusupdate (string layername, bool status)
{
If (mapcontrol1.map. Layers [layername]! = NULL & mapcontrol1.map. Layers [layername]. enabled!

= Status)
{
Mapcontrol1.map. Layers [layername]. Enabled = status;
}
}
Center the three layers to see the full Graph

/**////

/// Make all specified layers appear in the visible range of the map
///

///
Layer alias

Public void layercenter (string layername)
{
MapInfo. Data. Table [] tables = new MapInfo. Data. Table [1];
Tables [0] = MapInfo. Engine. session. Current. Catalog. gettable (layername );
If (tables [0] = NULL)
Return;
If (mapcontrol1.map. Layers [layername] = NULL)
Return;

If (mapcontrol1.map. Layers [layername]. Enabled = false)
Mapcontrol1.map. Layers [layername]. Enabled = true;

MapInfo. Mapping. imaplayerfilter =

MapInfo. Mapping. maplayerfilterfactory. filterbytable (tables );
MapInfo. Mapping. maplayerenumerator =

Mapcontrol1.map. layers. getmaplayerenumerator (imaplayerfilter );
Mapcontrol1.map. setview (maplayerenumerator );
Onfeatureunclick ();
}

4. Zoom in and out the map

/**////

/// Enlarge the map
///

///
Magnification, valid value: 1-10

Public void zoomin (uint times)
{
If (Times <1 | times> 10) return;
MapInfo. Geometry. Distance previuszoom = This. mapcontrol1.map. Zoom;
Mapcontrol1.map. Zoom = new MapInfo. Geometry. Distance (previuszoom. Value/

(2 * times), previuszoom. Unit );
}
/**////

/// Zoom out the map
///

///
Zoom in multiple, valid value: 1-10

Public void zoomout (uint times)
{
If (Times <1 | times> 10) return;
MapInfo. Geometry. Distance previuszoom = This. mapcontrol1.map. Zoom;
Mapcontrol1.map. Zoom = new MapInfo. Geometry. Distance (previuszoom. Value *

(2 * times), previuszoom. Unit );
}

5. Sequence of moving Layers
Mapcontrol1.map. layers. Move (index1, index2 );

6. Opacity of elements/Layers

/**////

/// Set whether the layer is transparent or not
///

///
Layer name

///
Opacity type all opacity border only has the border opacity (internal transparency)

None all transparent

///
If the border is not transparent, set the border color here.

Public void layertransparent (string layername, opaquetype, system. Drawing. Color

Bordercolor)
{

MapInfo. Styles. compositestyle = getopaquestyle (opaquetype, bordercolor );

// Create a connection and command to update table data
MapInfo. Data. miconnection connection = new MapInfo. Data. miconnection ();
Connection. open ();
MapInfo. Data. micommand command = connection. createcommand ();
Command. commandtext = "Update" + layername + "set OBJ = OBJ, mi_style = @ style ";
Command. Parameters. Add ("@ style", compositestyle );
Command. Prepare ();
Command. executenonquery ();

// Close the connection
Command. Cancel ();
Command. Dispose ();
Connection. Close ();
Connection. Dispose ();
}
/**////

/// Create a style
///

///
Opacity type: All is not transparent (white solid); border boundary is not transparent (fill part

Transparent); none transparent

///
If opaquetype = border, set the border color here.

/// Combination Style
Private MapInfo. Styles. compositestyle getopaquestyle (opaquetype

Opaquetype, system. Drawing. Color bordercolor)
{
MapInfo. Styles. simpleinterior;
If (opaquetype = opaquetype. All)
Simpleinterior = new MapInfo. Styles. simpleinterior (); // The default constructor is white and solid.
Else
Simpleinterior = new MapInfo. Styles. simpleinterior (1); // 0 is wire transparent, 1 is surface transparent

MapInfo. Styles. linewidth = new

MapInfo. Styles. linewidth (1, MapInfo. Styles. linewidthunit. Point );

MapInfo. Styles. simplelinestyle;
If (opaquetype = opaquetype. All)
Simplelinestyle = new MapInfo. Styles. simplelinestyle (linewidth );
Else if (opaquetype = opaquetype. Border)
Simplelinestyle = new MapInfo. Styles. simplelinestyle (linewidth, 2, bordercolor); // 2 indicates Filling

Transparent to display the outline
Else
Simplelinestyle = new MapInfo. Styles. simplelinestyle (linewidth, 0); // 0 indicates that all are transparent, that is, continuous Wheel

Invisible to profile

MapInfo. Styles. areastyle = new

MapInfo. Styles. areastyle (simplelinestyle, simpleinterior );

MapInfo. Styles. compositestyle = new

MapInfo. Styles. compositestyle (areastyle, null, null );

Return compositestyle;
}

7. Select all elements

MapInfo. Engine. session. Current. Catalog. Search (
Table,
MapInfo. Data. searchinfofactory. searchall (),
MapInfo. Engine. session. Current. Selections. defaultselection,
MapInfo. Data. resultsetcombinemode. Replace );

8. Set Coordinate System
By default, the coordsys used by mapxtreme is the longitude and latitude projection (longlat) and WGS84. I want to modify the projection type

Coordsystype. transversemercator, with the reference value datumid. pulkovo1942
MapInfo. Geometry. coordsysfactory

Coordsysfactory = MapInfo. Engine. session. Current. coordsysfactory;
Mapcontrol1.map. setdisplaycoordsys (coordsysfactory. createcoordsys ("MapInfo: coordsys

7,117, 20500000,0 "));

Coordsysfactory. createcoordsys ("MapInfo: coordsys 7,117, 20500000,0") default Origin

Yes (B = 0, L = 117). How should I write this string if I want to set the origin point to (23,117?
Coordsysfactory. createcoordsys ("MapInfo: coordsys 8, 7,114 ")

9 Save the new painting as a tab File
The source code below is to create a permanent table, add a feature to the table, and save it as a tab file on the hard disk.

Private MapInfo. Data. Table createnewmapdatatable (string tablename)
{
// The followingCodeIs to create a permanent table
MapInfo. Data. tableinfonative

Tableinfonative = newmapinfo. Data. tableinfonative (tablename );
Tableinfonative. tablepath = @ "D: \ data \" + tablename + ". tab ";
Tableinfonative. Columns. Add (MapInfo. Data. columnfactory. createintcolumn ("ID "));
Tableinfonative. Columns. Add (MapInfo. Data. columnfactory. createstylecolumn ());
MapInfo. Geometry. coordsys = mapcontrol1.map. getdisplaycoordsys ();

Tableinfonative. Columns. Add (MapInfo. Data. columnfactory. createfeaturegeometrycolumn (coordsys)

);
MapInfo. Data. Table

= MapInfo. Engine. session. Current. Catalog. createtable (tableinfonative );

// The following Code creates a temporary table
// MapInfo. Data. tableinfo

= MapInfo. Data. tableinfofactory. createtemp (tablename );
// Tableinfo. Columns. Add (MapInfo. Data. columnfactory. createintcolumn ("ID "));
// MapInfo. Data. Table

= MapInfo. Engine. session. Current. Catalog. createtable (tableinfo );

MapInfo. Mapping. featurelayer =

Newmapinfo. Mapping. featurelayer (table );
This. mapcontrol1.map. layers. Add (featurelayer );
Return table;
}

Private void addfeaturesandsave ()
{
MapInfo. Styles. simplelinestyle =

Newmapinfo. Styles. simplelinestyle (New

MapInfo. Styles. linewidth (1, MapInfo. Styles. linewidthunit. Point ));
MapInfo. Styles. compositestyle =

Newmapinfo. Styles. compositestyle (null, simplelinestyle, null, null );
MapInfo. Geometry. coordsys = mapcontrol1.map. getdisplaycoordsys ();

MapInfo. Data. Table = createnewmapdatatable ("newtable ");
MapInfo. Data. tableinfo = table. tableinfo;
While (......)
{
MapInfo. Data. Feature feature = newmapinfo. Data. feature (tableinfo. columns );

Feature. Geometry = ......
Feature. Style = ......
Feature ["ID"] = ......
Table. insertfeature (feature );
}
Tableinfo. writetabfile (); // Save As A. Tab File

Mapcontrol1.refresh ();
}

10. Calculate the scaling ratio.

/**////

/// Calculate the zoom ratio when you redraw the widget
///

///

///

protected void mapcontrol1_paint (Object sender, painteventargs e)
{< br> MapInfo. geometry. distance zoomdistance = This. mapcontrol1.map. zoom;
double zoom = convert. todouble (convert. toint32 (zoomdistance. value * 16.09)/10;
This. statusbar1.text = "zoom ratio:" + zoom. tostring () + "km";
}