请教一个简单问题？

Question

我在做一个三层的系统时（用webconnetion连服务端），编译能通过，运行是说：Project mdiapp.exe raised exception class EAccessViolation with message 'Access violation at address 0053A240 in modul 'mdiapp.exe', Read of address 0000006C', Process stopped. Use Step or Run to continue.
我是新手，大家能不能帮我看看，大概是什么问题啊，我错在什么地方？

Answer 1

关闭delphi,重新打开项目,再运行

Answer 2

好的，源码太长了，我把出现问题的那部分贴出来。
procedure TFrm_Main.Menu_StatisticClick(Sender: TObject);
var
    child : TForm_Query;
begin
    child := TForm_Query.Create(Application); //此处提示有问题。
    with child do
    begin
       caption:='°´×ʽðͳ¼Æ';
        height:=getheight(495);
           width:=getwidth(600);
           left:=getleft(600);
           top:=gettop(495);   
    end;
end;

Answer 3

把TForm_Query的FormCreate和Create方法贴出来。

Answer 4

我是新手，不知道你讲的是什么，是不是要把TForm_Query的源文件贴出来啊？谢谢

Answer 5

关闭delphi,
再运行,
应该可以，
你试试？

Answer 6

procedure FormClose(Sender: TObject; var Action: TCloseAction);  private
    { Private declarations }
  public
    { Public declarations }
    procedure Refresh_CB_ChargeItem();
  end;
Const
Orignwidth=1024;
Orignheight=768;
var
  Form_Query: TForm_Query;
  Param_Capital_Class,Param_Charge_Class :String;
  Param_Charge_Level : String;
  Param_ZSDW:String;
  Param_Charge_SystemCode,Param_Charge_OrgCode:String;
  Param_ChargeItem : String;
  Main_SQL,Select_SQL,From_SQL,Where_SQL,GroupOrder_SQL:String;
  SQL_Description : TStringList;
implementation
uses Unit_Show,Help,DMFrm;
{$R *.DFM}
procedure TForm_Query.FormCreate(Sender: TObject);
begin
    {CK_SYSCODE.visible := false;
    CK_ORGCODE.Visible := false;
    }
    KaiPiao_TimeTo.DateTime := now;
    KaiPiao_TimeFrom.DateTime := IncMonth(now,-1);
    UP_TimeTo.DateTime := now;
    UP_TimeFrom.DateTime := IncMonth(now,-1);
    {with CB_Capital_Class do
    begin
        Items.Append('01 »ù½ð£¨×ʽð`¸½¼Ó£©');
        Items.Append('02 ÐÐÕþÐÔÊÕ·Ñ');
        Items.Append('10 Ô¤ËãÄÚ×ʽð');
        Items.Append('11 Ô¤ËãÄڵĻù½ð£¨×ʽð`¸½¼Ó£©');
        Items.Append('12 Ô¤ËãÄÚµÄÐÐÕþÐÔÊÕ·Ñ');
        Items.Append('13 Ë°½ð');
        Items.Append('20 Ô¤ËãÍâ×ʽð');
        Items.Append('21 Ô¤ËãÍâµÄ»ù½ð£¨×ʽð`¸½¼Ó£©');
        Items.Append('22 Ô¤ËãÍâµÄÐÐÕþÐÔÊÕ·Ñ');
        Items.Append('23 ÊÂÒµÐÔÊÕ·Ñ');
        Items.Append('24 ÆäËûÊÕÈë');
        Items.Append('30 ¾­ÓªÐÔÊÕ·Ñ');
        Items.Append('40 µ¥Î»ÍùÀ´¿îÏî');
        Items.Append('50 Éϼ¶²¹ÖúÊÕÈë');
    end;
    }
    with CB_Charge_Level do
    begin
        Items.Append('004 ÏØÊм¶');
        Items.Append('003 µØÊм¶');
        Items.Append('002 Ê¡¼¶');
        Items.Append('001 ¹ú¼Ò¼¶(¼Æί)');
        items.append('000 ¹ú¼Ò¼¶(¹úÎñÔº)');
    end;
    with ChargeData.pub_ClientDataSet do
    begin
//        Close;
//        SQL.Clear;
//        SQL.ADD('Select LTRim(RTrim(CharCode)) + ''   ''  + LTRim(RTrim(CharName)) Charges from ChargeChar ');
//        Open;
//        First;
        Close;
        CommandText:='Select LTRim(RTrim(CharCode)) + ''   ''  + LTRim(RTrim(CharName)) Charges from ChargeChar ';
        Open;
        First;
        While not Eof do
        begin
            CB_Charge_Class.Items.Append(FieldByName('Charges').AsString);
            Next;
        end;//        Close;
//        SQL.Clear;
//        SQL.ADD('Select LTRim(RTrim(MoneyCode)) + ''   ''  + LTRim(RTrim(MoneyName)) Capitals from MoneyChar');
//        Open;
//        First;
        Close;
        CommandText:='Select LTRim(RTrim(MoneyCode)) + ''   ''  + LTRim(RTrim(MoneyName)) Capitals from MoneyChar';
        Open;
        First;
        While not Eof do
        begin
            CB_Capital_Class.Items.Append(FieldByName('Capitals').AsString);
            Next;
        end;//        Close;
//        SQL.Clear;
//        SQL.Add('Select LTrim(RTrim(SysCode)) + ''   '' + LTrim(RTrim(SysName)) ZSDW from System Where Len(LTrim(RTrim(SysCode))) = 2 order by ZSDW ');
//        Open;
//        First;
        Close;
        CommandText:='Select LTrim(RTrim(SysCode)) + ''   '' + LTrim(RTrim(SysName)) ZSDW from System Where Len(LTrim(RTrim(SysCode))) = 2 order by ZSDW ';
        Open;
        First;
        while not Eof do
        begin
            CB_ZSDW.Items.Append(FieldByName('ZSDW').AsString);
            Next;
        end;//        Close;
//        SQL.Clear;
//        SQL.ADD('Select LTrim(RTrim(SysCode)) + ''   '' + LTrim(RTrim(SysName)) SysCodes from System  where  SysCode In (Select Distinct Syscode from ChargeItem) ORDER BY SysCodes');
//        Open;
//        First;
        Close;
        CommandText:='Select LTrim(RTrim(SysCode)) + ''   '' + LTrim(RTrim(SysName)) SysCodes from System  where  SysCode In (Select Distinct Syscode from ChargeItem) ORDER BY SysCodes';
        Open;
        First;
        while not Eof do
        begin
            CB_Charge_SystemCode.Items.Append(FieldByName('SysCodes').AsString);
            Next;
        end;
        Close;
    end;
    {
        SQL.Clear;
        SQL.ADD('Select LTrim(RTrim(OrgCode)) + ''  '' + LTrim(RTrim(OrgName)) OrgCodes from Orglicence ORDER BY OrgCodes');
        Open;
        First;
        While not Eof do
        begin
            CB_Charge_OrgCode.Items.Append(FieldByName('OrgCodes').AsString);
            Next;
        end;
        Close;        SQL.Clear;
        SQL.ADD('Select distinct CharCode from ChargeItem');
        Open;
        First;
        while not Eof do
        begin
            if FieldByName('CharCode').Asstring = '001' then
                CB_ZSDW.Items.Append('001  Êм¶Õ÷ÊÕµ¥Î»');
            if FieldByName('CharCode').Asstring = '002' then
                CB_ZSDW.Items.Append('002  Õò¼¶Õ÷ÊÕµ¥Î»');
            Next;
        end;
        Close;
    end;
    }
    CB_Capital_Class.ItemIndex := 0;
    CB_Charge_Class.ItemIndex := 0;
    CB_Charge_Level.ItemIndex := 2;
    CB_ZSDW.ItemIndex := 0;
    CB_Charge_SystemCode.ItemIndex := 0;    {CB_Charge_SystemCode.ItemIndex := 0;
    CB_Charge_OrgCode.ItemIndex := 0;
    CB_ZSDW.ItemIndex := 0;
    }
    Param_Charge_Class := Copy(CB_Charge_Class.Text,1,Pos(' ',CB_Charge_Class.Text)-1);
    Param_Capital_Class := Copy(CB_Capital_Class.Text,1,Pos(' ',CB_Capital_Class.Text)-1);
    Param_Charge_Level := Copy(CB_Charge_Level.Text,1,Pos(' ',CB_Charge_Level.Text)-1);
    Param_ZSDW := Copy(CB_ZSDW.Text,1,Pos(' ',CB_ZSDW.Text)-1);
    Param_Charge_SystemCode := Copy(CB_Charge_SystemCode.Text,1,Pos(' ',CB_Charge_SystemCode.Text)-1);
    Param_Charge_OrgCode := '';
    Param_ChargeItem := '';
    
scaled:=true;
if(screen.width<>orignwidth)then
begin
height:=longint(height)*longint(screen.height) div orignheight;
width:=longint(width)*longint(screen.width) div orignwidth;
scaleby(screen.width,orignwidth);
end;
end;

Answer 7

procedure TForm_Query.CB_Charge_SystemCodeChange(Sender: TObject);
begin
    Param_Charge_SystemCode := Copy(CB_Charge_SystemCode.Text,1,Pos(' ',CB_Charge_SystemCode.Text)-1);
    if (CK_Charge_SystemCode.Checked and CK_Charge_OrgCode.Checked) then
    begin
      //CK_Charge_OrgCodeClick(Self);
      CK_Charge_OrgCodeClick(Self);
    end;
end;procedure TForm_Query.CB_Charge_OrgCodeChange(Sender: TObject);
begin
    Param_Charge_OrgCode := Copy(CB_Charge_OrgCode.Text,1,Pos(' ',CB_Charge_OrgCode.Text)-1);
end;procedure TForm_Query.CB_ZSDWChange(Sender: TObject);
begin
   Param_ZSDW := Copy(CB_ZSDW.Text,1,Pos(' ',CB_ZSDW.Text)-1);
   //Param_ZSDW := CB_ZSDW.ItemIndex;
   if (CK_ZSDW.Checked and CK_Charge_OrgCode.Checked) then
   begin
      //CK_Charge_SystemCodeClick(Self);
      CK_Charge_OrgCodeClick(Self);
   end;
end;procedure TForm_Query.CK_ZSDWClick(Sender: TObject);
begin
{if CK_ZSDW.Checked then
begin
   with Data.Pub_Query do
   begin
        Close;
        SQL.Clear;
        SQL.ADD('Select distinct CharCode from ChargeItem');
        Open;
        First;
        CB_ZSDW.Clear;
        while not Eof do
        begin
            if FieldByName('CharCode').Asstring = '001' then
                CB_ZSDW.Items.Append('001  &Ecirc;&ETH;&frac14;&para;&Otilde;÷&Ecirc;&Otilde;&micro;&yen;&Icirc;&raquo;');
            if FieldByName('CharCode').Asstring = '002' then
                CB_ZSDW.Items.Append('002  &Otilde;ò&frac14;&para;&Otilde;÷&Ecirc;&Otilde;&micro;&yen;&Icirc;&raquo;');
            Next;
        end;
        Close;
   end;
   CB_ZSDW.ItemIndex := 0;
   Param_ZSDW := Copy(CB_ZSDW.Text,1,Pos(' ',CB_ZSDW.Text)-1);
end
else
begin
   CB_ZSDW.Clear;
   Param_ZSDW := '';
end;
CK_Charge_SystemCodeClick(Self);
CK_Charge_OrgCodeClick(Self);
}
    //Param_ZSDW := CB_ZSDW.ItemIndex;
    Param_ZSDW := Copy(CB_ZSDW.Text,1,Pos(' ',CB_ZSDW.Text)-1);
    if (CK_Charge_OrgCode.Checked) then
    begin
      CK_Charge_OrgCodeClick(Self);
    end;
end;procedure TForm_Query.CK_Charge_SystemCodeClick(Sender: TObject);
begin
    {if CK_Charge_SystemCode.Checked then
    begin
        with Data.Pub_Query do
        begin
            Close;
            SQL.Clear;
            if Param_ZSDW <> '' then
                SQL.ADD('Select LTrim(RTrim(SysCode)) + ''   '' + LTrim(RTrim(SysName)) SysCodes from System  where  SysCode In (Select Distinct Syscode from ChargeItem Where CharCode = ''' +  Param_ZSDW + ''') ORDER BY SysCodes')
            else
                SQL.ADD('Select LTrim(RTrim(SysCode)) + ''   '' + LTrim(RTrim(SysName)) SysCodes from System  where  SysCode In (Select Distinct Syscode from ChargeItem ) ORDER BY SysCodes');
            Open;
            First;
            CB_Charge_SystemCode.Clear;
            while not Eof do
            begin
                CB_Charge_SystemCode.Items.Append(FieldByName('SysCodes').AsString);
                Next;
            end;
            Close;
        end;
        CB_Charge_SystemCode.ItemIndex := 0;
        Param_Charge_SystemCode := Copy(CB_Charge_SystemCode.Text,1,Pos(' ',CB_Charge_SystemCode.Text)-1);
    end
    else
    begin
        CB_Charge_SystemCode.Clear;
        Param_Charge_SystemCode := '';
    end;
    CK_Charge_OrgCodeClick(Self);
    }
    Param_Charge_SystemCode := Copy(CB_Charge_SystemCode.Text,1,Pos(' ',CB_Charge_SystemCode.Text)-1);
    if (CK_Charge_OrgCode.Checked) then
    begin
      CK_Charge_OrgCodeClick(Self);
    end;
end;procedure TForm_Query.CK_Charge_OrgCodeClick(Sender: TObject);
var SqlStr,where:String;
begin
    if CK_Charge_OrgCode.Checked then
    begin
        SqlStr := 'Select LTrim(RTrim(OrgCode)) + ''  '' + LTrim(RTrim(OrgName)) OrgCodes from Orglicence';
        Where := ' Where ';
        With chargeData.Pub_clientdataset do
        begin
//            SQL.Clear;
         close;
            {
            if Not ((Param_ZSDW = '') and (Param_Charge_SystemCode = '')) then
            begin
                Where := ' Where SubSysCode In (Select distinct SysCode from ChargeItem where ';
                if Param_ZSDW <> '' then
                    Where := Where + 'CharCode = ''' + Param_ZSDW + '''';                if Param_Charge_SystemCode <> '' then
                    if Param_ZSDW <> '' then
                        Where := Where + ' and SysCode = ''' + Param_Charge_SystemCode + ''''
                    else
                        Where := Where + ' SysCode = ''' + Param_Charge_SystemCode + '''';
                Where := Where + ')';
            end;
            }
            if CK_ZSDW.Checked then
            begin
                //if Param_ZSDW = 1 then Where := Where  + 'SysCode = ''00''  ';
                //if Param_ZSDW = 2 then Where := Where  + 'SysCode <> ''00''  ';
                Where := Where + ' SubString(OrgCode,1,2) = ''' + Param_ZSDW  + '''';
            end;
            if CK_Charge_SystemCode.Checked then
            begin
                if CK_ZSDW.Checked then Where := Where + ' And ';
                Where := Where + ' SubString(OrgCode,3,3) = ''' + Param_Charge_SystemCode + '''';
            end;
            if Where = ' Where ' then Where := '';
            SqlStr := SqlStr + Where + ' ORDER BY OrgCodes ';
            SQLShow('debug.txt',sqlstr);
//            SQL.ADD(SqlStr);
            commandtext:=sqlstr;
            Open;
            First;
            CB_Charge_OrgCode.Clear;
            While not Eof do
            begin
                CB_Charge_OrgCode.Items.Append(FieldByName('OrgCodes').AsString);
                Next;
            end;
            Close;
        end;
        CB_Charge_OrgCode.ItemIndex := 0;
        Param_Charge_OrgCode := Copy(CB_Charge_OrgCode.Text,1,Pos(' ',CB_Charge_OrgCode.Text)-1);
    end
    else
    begin
        CB_Charge_OrgCode.Clear;
        Param_Charge_OrgCode := '';
    end;
end;procedure TForm_Query.Btn_CloseClick(Sender: TObject);
begin
    self.release;
end;

Answer 8

下面还有很长，算了，我估计传参数的地方不对，我就把那部分贴出来。
    if CK_KaiPiao_Time.checked then
    begin
//        Data.Pub_Query.ParamByName('KPFrom').ASDateTime := KaiPiao_TimeFrom.Date;
//        Data.Pub_Query.ParamByName('KPTo').AsDateTime := KaiPiao_TimeTo.Date;
        chargedata.pub_clientdataset.params.ParamByName('KPFrom').ASDateTime := KaiPiao_TimeFrom.Date;
        chargedata.pub_clientdataset.params.ParamByName('KPTo').AsDateTime := KaiPiao_TimeTo.Date;
    end;
    if CK_UP_Time.Checked then
    begin
//        Data.Pub_Query.ParamByName('UPFrom').ASDateTime := UP_TimeFrom.Date;
//        Data.Pub_Query.ParamByName('UPTo').AsDateTime := UP_TimeTo.Date;
        chargedata.pub_clientdataset.params.ParamByName('UPFrom').ASDateTime := UP_TimeFrom.Date;
        chargedata.pub_clientdataset.params.ParamByName('UPTo').AsDateTime := UP_TimeTo.Date;
    end;