怎么让查询后功能是"显示上一条记录"的按钮正常使用

Question

没有点击查询按钮前,上一条记录按钮和下一条按钮都能正常使用,但是点击查询按钮后,上一条记录按钮和下一条记录按钮都失去作用,点了没有反应.查询按钮和上一条记录按钮都是使用ADOQuery1连接数据库.

Answer 1

查询代码:procedure TInfo.Button8Click(Sender: TObject);
var
    MS:TstringStream;       //查询
begin
  if (edit1.Text = '')then
      begin
          showmessage('学号不能为空。');
          edit1.SetFocus;
      end
  else
     with ADOQuery1 do
      begin
          Close;
          SQL.Clear;
          SQL.Add('SELECT * FROM StuInfo WHERE StuID = ''' +edit1.Text+'''' );
          Open;
          if IsEmpty then
              begin
                  showmessage('没有这个学生记录。');
                  //edit1.SetFocus;
                  button13.Click;
              end
          else
              begin
                edit2.Text:=ADOQuery1.FieldByName('StuName').AsString;    //显示基本信息
                edit3.Text:=ADOQuery1.FieldByName('StuBirth').AsString;
                edit4.Text:=ADOQuery1.FieldByName('StuClass').AsString;
                edit5.Text:=ADOQuery1.FieldByName('StuFather').AsString;
                edit6.Text:=ADOQuery1.FieldByName('StuMother').AsString;
                edit8.Text:=ADOQuery1.FieldByName('FathTele').AsString;
                edit9.Text:=ADOQuery1.FieldByName('MothTele').AsString;
                edit7.Text:=ADOQuery1.FieldByName('StuTeaName').AsString;
    //image1.Picture.Graphic := nil;
                if ADOQuery1.FieldByName('StuPicture').isNull=false then     //显示图片
                  begin
                      MS:=TstringStream.Create('');
                      TBlobField(ADOQuery1.FieldByName('StuPicture')).SaveToStream(MS);
                      MS.Position := 0;
                      image1.Picture.Graphic.LoadFromStream(MS);
                      MS.Free;
                  end
                else
                   begin
                     image1.Picture.Graphic.LoadFromFile('D:\较好版本\333333\并蒂莲.jpg');
                   end;
                with ADOQuery7 do
                begin
                  ADOQuery7.Close;
                  ADOQuery7.SQL.Clear;
                  ADOQuery7.SQL.Add('select * from FingerPrint where StuID = '''+edit1.Text+''' and Relation =''本人''');
                  ADOQuery7.Open;
                  //edit14.Text:=ADOQuery7.FieldByName('Relation').AsString;
                  if IsEmpty then
                    begin
                      label17.Caption:='指纹没有登记';
                    end
                  else
                    begin
                      label17.Caption:='指纹已经登记';
                    end;
                //info.FormShow(Sender);
                end;
                button5.Enabled:=true;
                button2.Enabled:=true;
                button7.Enabled:=true;
              end;
        end;end;

Answer 2

上一条记录代码
procedure TInfo.Button15Click(Sender: TObject);
var
    MS:TstringStream;      //上一条记录
begin
  //with ADOQuery1 do
  ADOQuery1.Prior;
  if not ADOQuery1.Bof then
  begin
    Button15.Enabled := true;
  end
  else
  begin
    Button15.Enabled := false;
    Button17.Enabled:=false;
  end;
    edit2.Text:=ADOQuery1.FieldByName('StuName').AsString;
    edit1.Text:=ADOQuery1.FieldByName('StuID').AsString;
    edit3.Text:=ADOQuery1.FieldByName('StuBirth').AsString;
    edit4.Text:=ADOQuery1.FieldByName('StuClass').AsString;
    edit5.Text:=ADOQuery1.FieldByName('StuFather').AsString;
    edit6.Text:=ADOQuery1.FieldByName('StuMother').AsString;
    edit8.Text:=ADOQuery1.FieldByName('FathTele').AsString;
    edit9.Text:=ADOQuery1.FieldByName('MothTele').AsString;
    edit7.Text:=ADOQuery1.FieldByName('StuTeaName').AsString;
    //image1.Picture.Graphic := nil;
    if ADOQuery1.FieldByName('StuPicture').isNull=false then
        begin
        MS:=TstringStream.Create('');
        TBlobField(ADOQuery1.FieldByName('StuPicture')).SaveToStream(MS);
        MS.Position := 0;
        image1.Picture.Graphic.LoadFromStream(MS);
        MS.Free;
        end
    else
      begin
        image1.Picture.Graphic.LoadFromFile('D:\较好版本\333333\并蒂莲.jpg');
      end;

Answer 3

你所说的失去作用是指死循环了，还是指在查询的过程中其他按钮无法点击阿，如果是后者你可以试试在查询按钮中加入这一句
Application.ProcessMessages;