delphi使用BDE创建一个简易的dbf查询器

想打开一个dbf文档，之前一直困惑于使用什么驱动，如何连接，参考他人的做法，原来如此简单。

 

  edtDir.text:=opendialog1.FileName;
 dbdir:=ExtractFileDir(opendialog1.FileName);
 dbname:=extractfilename(opendialog1.FileName);
 dbname:=copy(dbname,1,(length(dbname)-4));//去掉.dbf, 不去也不会有影响

  with table1 do
  begin
      Databasename:=dbdir;//设置库路径
      TableName:=dbname;
      Open;
 end;

 

顺便做了一个简单的dbf查询器：

 

代码如下：

 

implementation
 var
  dbdir,dbname:string;
{$R *.dfm}

{思路：使用BDE驱动，共用一个DataSource，因此DS变动时，DBGrid以及
       条件筛选的字段列表也会改变}


procedure TForm6.btnSetDirClick(Sender: TObject);
begin

 if opendialog1.Execute then
 begin
   {初始化}
 cmbfield.Clear;
 edtvalue.Clear;

 if table1.Active then
 begin
    table1.Active:=false;
   if table1.Filtered then      //必须取消filter,否则出错
     table1.Filtered:=false;
   table1.filter:='';
 end;
  if query1.Active then
  begin
    query1.Active:=false;
    query1.SQL.Clear;
  end;

  //datasource1.DataSet.Active:=false;
{初始化结束}
   edtDir.text:=opendialog1.FileName;
   dbdir:=ExtractFileDir(opendialog1.FileName);
   dbname:=extractfilename(opendialog1.FileName);
   dbname:=copy(dbname,1,(length(dbname)-4));

  with table1 do
  begin
      Databasename:=dbdir;
      TableName:=dbname;
      Open;
      datasource1.DataSet:=table1;
      memo1.Lines.Clear;
       if dbname[1] in ['0'..'9'] then //如果数字开头，必须使用''
       dbname:=quotedstr(dbname);
      memo1.Lines.Add('select * from '+dbname);
   end;//with
 end; //if

end;

procedure TForm6.btnTjQryClick(Sender: TObject);
var
  strtj:string;
begin

  strtj:=cmbfield.Items[cmbfield.ItemIndex]+ ' '+cmbtj.Items[cmbtj.ItemIndex];
  strtj:=strtj+ ' '+quotedstr(edtvalue.Text);

  //showmessage(strtj);
   with DataSource1.DataSet do
   begin
   if not active  then
     active:=true;
     filter:=strtj;
     filtered:=true;
     btncancel.Enabled:=true;
   end;
end;


 {更新字段下拉列表；以及标签记录数}
procedure TForm6.DataSource1DataChange(Sender: TObject; Field: TField);
var
  i:integer;
begin

   i:=cmbfield.ItemIndex; //保留原itemindex
  DataSource1.DataSet.GetFieldNames(cmbfield.Items);
  cmbfield.ItemIndex:=i;

  btnTjqry.Enabled:=true;
  lblcount.Caption:='      --共有'+inttostr(Datasource1.DataSet.recordcount)+'条记录';
end;

procedure TForm6.btnCancelClick(Sender: TObject);
begin
 with DataSource1.DataSet do
 begin
  if Filtered then
  begin
      Filtered:=false;
      btnCancel.Enabled:=false;
  end;
 end;
end;

procedure TForm6.btnQryClick(Sender: TObject);
begin
with query1 do
begin
 if table1.active  then   table1.active:=false;

   if active then active:=false;
   Databasename:=dbdir;
   sql.Text:=memo1.Lines.Text;
    open;
  datasource1.DataSet:=query1;
  btnTjQry.Enabled:=false;

end;

end;