MapXtreme开发（二）

1、改变地图的坐标系统
使用如下方法改变地图的坐标系统
Map map = mapControl1.Map;
MapInfo.Geometry.CoordSys coordSys = Session.Current.CoordSysFactory.CreateLongLat(DatumID.WGS84);//.NAD83);
//DatumID为枚举类型，其中列出了经纬度坐标系统的大量枚举类型，参阅帮助可获取更多信息。
map.SetDisplayCoordSys(coordSys);
2、如何改变一个地图的Zoom单位
mapControl1.Map.Zoom = new MapInfo.Geometry.Distance(mapControl1.Map.Zoom.value,MapInfo.Geometry.DistanceUnit.Kilometer);
也可以分开写成如下格式：
MapInfo.Geometry.Distance d = new MapInfo.Geometry.Distance(1000, DistanceUnit.Kilometer);
mapControl1.Map.Zoom = d;
注意在这里的1000，限制了用户的ZOOM范围只能为1000km。

用以下方法更加合适：
mapControl1.Map.Zoom = new MapInfo.Geometry.Distance(
  CoordSys.ConvertDistanceUnits(
  DistanceUnit.Kilometer,
  mapControl1.Map.Zoom.value,
  mapControl1.Map.Zoom.Unit),
  DistanceUnit.Kilometer);
3、如何为mapControl中的一个地图表增加主题

如何为mapControl中的一个地图表增加主题？
为SHENGQU这个面样式表来增加主题。
// Listen to some map events
mapControl1.Resize += new EventHandler(mapControl1_Resize);
//在此事件中处理当mapControl改变大小时来重新定位主题表的位置。

// Create a ranged theme on the USA layer.
Map map = mapControl1.Map;
FeatureLayer lyr = map.Layers["SHENGQU"] as MapInfo.Mapping.FeatureLayer;

RangedTheme thm = new MapInfo.Mapping.Thematics.RangedTheme(
  lyr,
  "Round(MI_Area(Obj, 'sq km', 'Spherical'), 1)",
  "Area (square kilometer)",
  5,
  MapInfo.Mapping.Thematics.DistributionMethod.EqualRangeSize);//.EqualCountPerRange);

lyr.Modifiers.Append(thm);

// Change the default fill colors from Red->Gray to White->Blue
AreaStyle ars;
// Get the style from our first bin
CompositeStyle cs = thm.Bins[0].Style;
// Get the region -- Area -- style
ars = cs.AreaStyle;
// Change the fill color
ars.Interior = StockStyles.WhiteFillStyle();
// Update the CompositeStyle with the new region color
cs.AreaStyle = ars;
// Update the bin with the new CompositeStyle settings
thm.Bins[0].Style = cs;

// Change the style settings on the last bin
int nLastBin = thm.Bins.Count - 1;
cs = thm.Bins[nLastBin].Style;
ars = cs.AreaStyle;
ars.Interior = StockStyles.BlueFillStyle();
thm.Bins[nLastBin].Style = cs;

// Tell the theme how to fill in the other bins
thm.SpreadBy = SpreadByPart.Color;
thm.ColorSpreadBy = ColorSpreadMethod.Rgb;
thm.RecomputeStyles();

// Create a legend
legend = map.Legends.CreateLegend(new Size(5, 5));
legend.Border = true;
ThemeLegendFrame frame = LegendFrameFactory.CreateThemeLegendFrame("Area", "Area", thm);
legend.Frames.Append(frame);
frame.Title = "Area (sq. mi.)";
map.Adornments.Append(legend);
// Set the initial legend location to be the lower right corner of the map control.
System.Drawing.Point pt = new System.Drawing.Point(0, 0);
pt.X = mapControl1.Size.Width - legend.Size.Width;
pt.Y = mapControl1.Size.Height - legend.Size.Height;
legend.Location = pt;
在mapControl1_Resize事件中针对mapControl大小的改变来变化主题表的位置。
private void mapControl1_Resize(object sender, System.EventArgs e)
{
  Control control = (Control)sender;

  // Move the Legend to the lower right corner...
  System.Drawing.Point pt = new System.Drawing.Point(0, 0);
  pt.X = control.Size.Width - legend.Size.Width;
  pt.Y = control.Size.Height - legend.Size.Height;
  legend.Location = pt;
}
5、数据绑定
数据绑定的例子。当数据表中的值改变，Pennsylvania 州的颜色会改变。 
private void button1_Click(object sender, System.EventArgs e)
{
Session.Current.Catalog.CloseAll();
Table USATab = USATab = Session.Current.Catalog.OpenTable(@"c:\program files\mapinfo\mapxtreme.0\samples\data\usa.tab");
FeatureLayer fl = new FeatureLayer(USATab);
mapControl1.Map.Layers.Add(fl);

System.Data.DataTable dt = new System.Data.DataTable("USStuff");
dt.Columns.Add("USState", typeof(System.String));
dt.Columns.Add("SomeIndValue", typeof(System.String));
dt.Rows.Add(new object[]{"NY", "Dem"});
dt.Rows.Add(new object[]{"PA", "Rep"});
dt.Rows.Add(new object[]{"VT", "Dem"});
dt.Rows.Add(new object[]{"OH", "Rep"});

TableInfoAdoNet tian = new TableInfoAdoNet("VoteRecord", dt);
Table USVote = Session.Current.Catalog.CreateTable(tian);
Columns cols = new Columns();
cols.Add(USVote.TableInfo.Columns["SomeIndValue"].Clone());

USATab.AddColumns(cols, BindType.DynamicCopy, USVote, "USState", Operator.Equal, "State");

MapInfo.Mapping.Thematics.IndividualValueTheme thm = new MapInfo.Mapping.Thematics.IndividualValueTheme(fl, "SomeIndValue", "StateVotingRecord");
fl.Modifiers.Append(thm);
timer1.Start() ;
}

private void timer1_Tick(object sender, System.EventArgs e)
{
FeatureLayer fl = mapControl1.Map.Layers[0] as FeatureLayer;
System.Data.DataTable dt = (Session.Current.Catalog.GetTable("VoteRecord").TableInfo as TableInfoAdoNet).DataTable;
dt.Rows[1][1] = dt.Rows[1][1].ToString()=="Rep"?"Dem":"Rep";

Session.Current.Catalog.GetTable("VoteRecord").Refresh();
fl.Table.Refresh();
fl.Invalidate();
}
6、一段旋转图元几何体的代码
Catalog cata  = MapInfo.Engine.Session.Current.Catalog;
   Table t = cata.GetTable("World");
   Feature f = cata.SearchForFeature(t, MapInfo.Data.SearchInfoFactory.SearchWhere("Country='Japan'"));
   DPoint dp = new DPoint(f.Geometry.GeometricCentroid.x, f.Geometry.GeometricCentroid.y);
   f.Geometry.GeometryEditor.Rotate(dp, 90);
   f.Geometry.EditingComplete();
   t.UpdateFeature(f);
   mapControl1.Map.SetView(f);
7、在Web应用中使用InfoTip

1．在地图网页的