在MapX中实现图元闪烁原码

左半边

在MapX中实现图元闪烁原码
MapX图元分三种类型：
1、线(Line)，即miFeatureTypeLine
2、区域(Region)，即miFeatureTypeRegion
3、点符号(Symbol)，即miFeatureTypeSymbol
加入一个时钟控件，并在时钟控件中实现以下代码：
procedure TMapFrm.tmFlashSelectTimer(Sender: TObject);
var
ft: CMapXFindFeature;
lyr: CMapXLayer;
bExist: Boolean;
i: Integer;
str: String;
ds: CMapXDataset;
begin
bExist := False;
for i := 1 to mapCity.Layers.Count do
begin
if mapCity.Layers.Item[i].Name = m_strSelLyr then
begin
bExist := True;
break;
end;
end;
if not bExist then
begin
tmFlashSelect.Enabled := False;
MsgFrm := TMsgFrm.Create(Self);
MsgFrm.m_strMsg := Format('图层[%s]信息不存在!',[m_strSelLyr]);
MsgFrm.ShowModal;
MsgFrm.Free;
Exit;
end;
lyr := mapCity.Layers._Item(m_strSelLyr);
ds := mapCity.Datasets.Add(miDataSetLayer, lyr ,EmptyParam, EmptyParam, EmptyParam, EmptyParam,
EmptyParam, EmptyParam);
lyr.Find.FindDataset := ds;
lyr.Find.FindField := ds.Fields.Item[1];
str := Format('%d',[m_nSelID]);
ft := lyr.Find.Search(str,EmptyParam);
if ft.FindRC mod 10 <> 1 then
begin
tmFlashSelect.Enabled := False;
MsgFrm := TMsgFrm.Create(Self);
MsgFrm.m_strMsg := Format('单位点[%s]信息不存在!',[m_strCorpName]);
MsgFrm.ShowModal;
MsgFrm.Free;
Exit;
end;
case ft.type_ of
miFeatureTypeLine:
begin
if ft.Style.LineColor = miColorWhite then
ft.Style.LineColor := miColorRed
else
ft.Style.LineColor := miColorWhite;
end;
miFeatureTypeRegion:
begin
if ft.Style.RegionColor = miColorGreen then
ft.Style.RegionColor := miColorRed
else
ft.Style.RegionColor := miColorGreen;
end;
miFeatureTypeSymbol:
begin
if not m_bFlashSel then
lyr.Selection.Replace(ft)
else
lyr.Selection.ClearSelection;
m_bFlashSel := not m_bFlashSel;
end;
end;
ft.Update(EmptyParam, EmptyParam);
if not m_bCenter then
begin
m_bCenter := True;
mapCity.CenterX := ft.CenterX;
mapCity.CenterY := ft.CenterY;
mapCity.Refresh;
end;
end;
我这里是把选中的图元实现闪烁，并把图元居中
实现图元闪烁的另一个方法：
假设图元原大小是20，改变后大小是15
if ft.Style.SymbolBitmapSize＝20 then
ft.Style.SymbolBitmapSize:=15
else
ft.Style.SymbolBitmapSize:=20;
ft.Update(EmptyParam, EmptyParam);
ft是symbol类型的