const   
      zoommax=1.8;     //地圖放大最大值   
      zoommin=3000;   //地圖縮小最大值   
      zoomintool=1;   //自定義地圖放大工具   
      zoomouttool=2;//自定義地圖縮小工具   
    
      form1.Map1.CreateCustomTool(zoomintool,mitooltypepoint,miselectcursor);   //創建放大工具   
      form1.Map1.CreateCustomTool(zoomouttool,mitooltypepoint,miselectcursor);//創建縮小工具   
    
  procedure   mapzoomin(x,y:double);   
  begin   
      if   zoomnum   >   100   then     //zoomnum   地圖縮放當前值   
      begin   
          if   zoomnum   >   300   then   
          begin   
              zoomnum:=zoomnum-150;   
          end   
          else   
          begin   
              zoomnum:=zoomnum-80;   
          end;   
      end   
      else   
      begin   
          if   zoomnum   >   30   then   
          begin   
              zoomnum:=zoomnum-20;   
          end   
          else   
          begin   
              if   zoomnum   >   10   then   
              begin   
                  zoomnum:=zoomnum-5;   
              end   
              else   
              begin   
                  zoomnum:=zoomnum-2;   
              end;   
          end;   
    
      end;   
      if   zoomnum<zoommax   then   zoomnum:=zoommax;   
      form1.Map1.ZoomTo(zoomnum,x,y);   
  end;   
    
  procedure   TForm1.Map1ToolUsed(Sender:   TObject;   ToolNum:   Smallint;   X1,   Y1,   
      X2,   Y2,   Distance:   Double;   Shift,   Ctrl:   WordBool;   
      var   EnableDefault:   WordBool);   
  begin   
      if   toolnum=   zoomintool   then   
      begin   
          mapzoomin(x1,y1);   
      end;   
  end;