query.txt

校园GIS系统——介绍校园个部门

uunit query;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, MapObjects2_TLB, Buttons;

type
  TQueryFrm = class(TForm)
    CbbLayer: TComboBox;
    LbField: TListBox;
    Lbvalue: TListBox;
    EdtExpression: TEdit;
    SpeedButton1: TSpeedButton;
    SpeedButton2: TSpeedButton;
    SpeedButton3: TSpeedButton;
    SpeedButton4: TSpeedButton;
    SpeedButton5: TSpeedButton;
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    Label4: TLabel;
    BbQuery: TBitBtn;
    BbClear: TBitBtn;
    SpeedButton6: TSpeedButton;
    procedure FormActivate(Sender: TObject);
    procedure CbbLayerChange(Sender: TObject);
    procedure LbFieldClick(Sender: TObject);
    procedure LbFieldDblClick(Sender: TObject);
    procedure SpeedButton1Click(Sender: TObject);
    procedure LbvalueDblClick(Sender: TObject);
    procedure BbClearClick(Sender: TObject);
    procedure BbQueryClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  QueryFrm: TQueryFrm;
  Myrecord:imorecordSet;
implementation

uses Unitmain;

{$R *.dfm}

procedure TQueryFrm.FormActivate(Sender: TObject);
var
i:integer;

begin
   CbbLayer.clear;
   LbField.Clear;
   Lbvalue.Clear;
   for i:=0 to MainFrm.MainMap.Layers.Count-1 do
     begin
        Currentlayer:=ImoMaplayer(MainFrm.MainMap.Layers.Item(i));
        CbbLayer.Items.Add(Currentlayer.Name);
        //添加图层
     end;
        CbbLayer.Itemindex:=0;
        CbbLayer.OnChange(sender);
end;

procedure TQueryFrm.CbbLayerChange(Sender: TObject);
var
MyTableDesc:imoTableDesc;
i:integer;
begin
  MyTableDesc:=CoTableDesc.Create;
  Currentlayer:=ImoMaplayer(MainFrm.MainMap.Layers.Item(CbbLayer.Text));
  MyTableDesc:=Currentlayer.Records.TableDesc;
  LbField.Clear;
  for i:=0 to MyTableDesc.FieldCount-1 do
    begin
       LbField.Items.Add(MyTableDesc.FieldName[i]);
       //添加字段
    end;
    LbField.ItemIndex:=0;
    LbField.OnClick(sender);
end;

procedure TQueryFrm.LbFieldClick(Sender: TObject);
var
MyStrings:ImoStrings;
i:integer;
begin
   MyStrings:=CoStrings.Create;
   LbValue.Clear;
   Myrecord:=CurrentLayer.Records;
   Myrecord.MoveFirst;
   While not MyRecord.EOF do
     begin
     //过滤重复值
       MyStrings.Add(Myrecord.Fields.Item(LbField.Items.Strings[LbField.ItemIndex]).ValueAsString);
       Myrecord.MoveNext;
       
     end;
   for i:=0 to MyStrings.Count - 1 do
   //添加值
     LbValue.Items.Add(MyStrings.Item(i));
end;

procedure TQueryFrm.LbFieldDblClick(Sender: TObject);
begin
   EdtExpression.Text:=EdtExpression.Text+' '+Lbfield.Items.Strings[LbField.itemindex];
end;

procedure TQueryFrm.SpeedButton1Click(Sender: TObject);
begin
  if sender is TSpeedButton then
  //控制快键
     EdtExpression.Text:=EdtExpression.Text+' '+(sender as TSpeedButton).Caption;
     
end;

procedure TQueryFrm.LbvalueDblClick(Sender: TObject);
var
ThisTableDesc:ImoTableDesc;
begin
   ThisTableDesc:=coTableDesc.Create;
   ThisTableDesc:=CurrentLayer.Records.TableDesc;
   Case ThisTableDesc.FieldType[LbField.ItemIndex] of
     MoString:
              EdtExpression.Text:=EdtExpression.Text+' '+chr(39)+
                                    LbValue.Items.Strings[LbValue.itemindex]+chr(39);
   else
   //表达式的显示
      EdtExpression.Text:=EdtExpression.Text+''+LbValue.Items.Strings[LbValue.itemindex];
   end;

end;
procedure TQueryFrm.BbClearClick(Sender: TObject);
begin
   EdtExpression.Text:='';
end;

procedure TQueryFrm.BbQueryClick(Sender: TObject);

begin
   if EdtExpression.Text<>'' then
   begin

      MainFrm.FindRecord:= CurrentLayer.SearchExpression(EdtExpression.Text);
      EventNumber:=2;
      MainFrm.MainMap.Refresh;
      {MainFrm.FindRecord.Export('F\:pp.shp',CurrentLayer.CoordinateSystem);}
       //输出结果
   end
   else
   Application.MessageBox('请输入表达式','提示',Mb_Ok);
end;

end.