自学教程：C++ CheckChange函数代码示例

void dlgTablespace::OnVarAdd(wxCommandEvent &ev){    wxString name=cbVarname->GetValue();    wxString value;    if (chkValue->IsShown())        value = chkValue->GetValue() ? wxT("on") : wxT("off");    else        value = txtValue->GetValue().Strip(wxString::both);    if (value.IsEmpty())        value = wxT("DEFAULT");    if (!name.IsEmpty())    {        long pos=lstVariables->FindItem(-1, name);        if (pos < 0)        {            pos = lstVariables->GetItemCount();            lstVariables->InsertItem(pos, name, 0);        }        lstVariables->SetItem(pos, 1, value);    }	dirtyVars = true;    CheckChange();}

void dlgTrigger::OnChange(wxCommandEvent &ev){	if (chkUpdate->GetValue())	{		cbColumns->Enable();	}	else	{		if (lstColumns->GetItemCount() > 0)		{			if (wxMessageBox(_("Removing the UPDATE event will cause the column list to be cleared. Do you wish to continue?"), _("Remove UPDATE event?"), wxYES_NO) != wxYES)			{				chkUpdate->SetValue(true);				return;			}			// Move all the columns back to the combo			for (int pos = lstColumns->GetItemCount(); pos > 0; pos--)			{				wxString colName = lstColumns->GetItemText(pos - 1);				lstColumns->DeleteItem(pos - 1);				cbColumns->Append(colName);			}		}		cbColumns->Disable();		btnAddCol->Disable();		btnRemoveCol->Disable();	}	CheckChange();}

void dlgJob::OnChangeSchedule(wxCommandEvent &ev){	long pos = lstSchedules->GetSelection();	pgaSchedule *obj = (pgaSchedule *) StrToLong(lstSchedules->GetText(pos, 3));	dlgSchedule schedule(&scheduleFactory, mainForm, obj, job);	schedule.CenterOnParent();	schedule.SetConnection(connection);	if (schedule.Go(true) != wxID_CANCEL)	{		lstSchedules->SetItem(pos, 0, schedule.GetName());		lstSchedules->SetItem(pos, 1, schedule.GetComment());		if (lstSchedules->GetText(pos, 3).IsEmpty())		{			wxString *scheduleSql = new wxString(schedule.GetInsertSql());			lstSchedules->SetItemData(pos, (long)scheduleSql);		}		else		{			wxString *scheduleSql = new wxString(schedule.GetUpdateSql());			lstSchedules->SetItemData(pos, (long)scheduleSql);		}		CheckChange();	}}

void dlgFunction::OnChangeArg(wxCommandEvent &ev){	if (GetSelectedDirection() == wxT("VARIADIC") &&	        !cbDatatype->GetValue().EndsWith(wxT("[]")))	{		wxLogError(_("Only array types can be VARIADIC."));		return;	}	int row = lstArguments->GetSelection();	if (row >= 0)	{		lstArguments->SetItem(row, 0, cbDatatype->GetValue());		lstArguments->SetItem(row, 1, GetSelectedDirection());		lstArguments->SetItem(row, 2, txtArgName->GetValue());		if (isBackendMinVer84)			lstArguments->SetItem(row, 3, txtArgDefVal->GetValue());		if (!function)			argOids.Item(row) = typOids.Item(cbDatatype->GetGuessedSelection());		txtArguments->SetValue(GetArgs());	}	OnChangeArgName(ev);	CheckChange();}

void dlgRole::OnVarRemove(wxCommandEvent &ev){	if (lstVariables->GetSelection() == wxNOT_FOUND)		return;	lstVariables->DeleteCurrentItem();	CheckChange();}

void dlgForeignServer::OnAddOption(wxCommandEvent &ev){	bool found = false;	for (int pos = 0 ; pos < lstOptions->GetItemCount() ; pos++)	{		if (lstOptions->GetText(pos).IsSameAs(txtOption->GetValue(), false))		{			lstOptions->SetItem(pos, 1, txtValue->GetValue());			found = true;			break;		}	}	if (!found)	{		lstOptions->AppendItem(txtOption->GetValue(), txtValue->GetValue());	}	txtOption->SetValue(wxT(""));	txtValue->SetValue(wxT(""));	btnAdd->Disable();	CheckChange();}

void dlgForeignTable::OnSelChangeTypOrLen(wxCommandEvent &ev){	CheckLenEnable();	txtLength->Enable(isVarLen);	txtPrecision->Enable(isVarPrec);	CheckChange();	OnChangeMember(ev);}

void dlgIndex::OnAddCol(wxCommandEvent &ev){	wxString colName = cbColumns->GetValue();	if (!colName.IsEmpty())	{		long colIndex = lstColumns->InsertItem(lstColumns->GetItemCount(), colName, columnFactory.GetIconId());		if (this->database->BackendMinimumVersion(8, 3))		{			if (chkDesc->GetValue())			{				if (chkDesc->IsEnabled())					lstColumns->SetItem(colIndex, 1, wxT("DESC"));				if (rdbNullsLast->GetValue())				{					if (rdbNullsLast->IsEnabled())						lstColumns->SetItem(colIndex, 2, wxT("LAST"));				}				else				{					if (rdbNullsLast->IsEnabled())						lstColumns->SetItem(colIndex, 2, wxT("FIRST"));				}			}			else			{				if (chkDesc->IsEnabled())					lstColumns->SetItem(colIndex, 1, wxT("ASC"));				if (rdbNullsFirst->GetValue())				{					if (rdbNullsFirst->IsEnabled())						lstColumns->SetItem(colIndex, 2, wxT("FIRST"));				}				else				{					if (rdbNullsLast->IsEnabled())						lstColumns->SetItem(colIndex, 2, wxT("LAST"));				}			}			lstColumns->SetItem(colIndex, 3, cbOpClass->GetValue());			lstColumns->SetItem(colIndex, 4, cbCollation->GetValue());		}		cbColumns->Delete(cbColumns->GetCurrentSelection());		if (cbColumns->GetCount())			cbColumns->SetSelection(0);		CheckChange();		if (!cbColumns->GetCount())			btnAddCol->Disable();	}}

void dlgFunction::OnChangeSetof(wxCommandEvent &ev){	if (chkSetof->GetValue() && connection->BackendMinimumVersion(8, 3) && !isProcedure)		txtRows->Enable();	else		txtRows->Disable();	CheckChange();}

void dlgTablespace::OnVarRemove(wxCommandEvent &ev){    if (lstVariables->GetSelection() >= 0)    {        lstVariables->DeleteCurrentItem();	    dirtyVars = true;        CheckChange();    }}

int dlgServer::GoNew(){	if (cbSSL->GetValue().IsEmpty())		return Go(true);	else	{		CheckChange();		return ShowModal();	}}

void dlgJob::OnRemoveSchedule(wxCommandEvent &ev){	delete (wxString *)lstSchedules->GetItemData(lstSchedules->GetSelection());	lstSchedules->DeleteCurrentItem();	btnChangeSchedule->Disable();	btnRemoveSchedule->Disable();	CheckChange();}

void dlgDomain::OnSelChangeTyp(wxCommandEvent &ev){	if (!domain)	{		cbDatatype->GuessSelection(ev);		CheckLenEnable();		txtLength->Enable(isVarLen);		CheckChange();	}}

void OpPackageKitProgress::Update(){    if (CheckChange() == false) {        // No change has happened skip        return;    }    // Set the new percent    pk_backend_job_set_percentage(m_job, static_cast<unsigned int>(Percent));}

void dlgUser::OnChangeCal(wxCalendarEvent &ev){	CheckChange();    bool timEn=ev.GetDate().IsValid();    timValidUntil->Enable(timEn);    if (!timEn)        timValidUntil->SetTime(wxDefaultDateTime);    else        timValidUntil->SetTime(wxDateTime::Today());}

void dlgSchedule::OnChangeException(wxCommandEvent &ev){	if (!calException->GetValue().IsValid() && timException->GetValue().IsNull())	{		wxMessageBox(_("You must enter a valid date and/or time!"), _("Add exception"), wxICON_EXCLAMATION | wxOK, this);		return;	}	wxString exDate, exTime;	if (calException->GetValue().IsValid())		exDate = calException->GetValue().FormatDate();	else		exDate = _("<any>");	if (!timException->GetValue().IsNull())		exTime = timException->GetValue().Format();	else		exTime = _("<any>");	long item = lstExceptions->GetFocusedItem();	for (int pos = 0; pos < lstExceptions->GetItemCount(); pos++)	{		if (item != pos)		{			if (lstExceptions->GetText(pos, 0) == exDate &&			        lstExceptions->GetText(pos, 1) == exTime)			{				wxMessageBox(_("The specified exception already exists!"), _("Add exception"), wxICON_EXCLAMATION | wxOK, this);				return;			}			if (lstExceptions->GetText(pos, 0) == exDate &&			        lstExceptions->GetText(pos, 1) == _("<any>"))			{				wxMessageBox(_("An exception already exists for any time on this date!"), _("Add exception"), wxICON_EXCLAMATION | wxOK, this);				return;			}			if (lstExceptions->GetText(pos, 1) == exTime &&			        lstExceptions->GetText(pos, 0) == _("<any>"))			{				wxMessageBox(_("An exception already exists for this time on any date!"), _("Add exception"), wxICON_EXCLAMATION | wxOK, this);				return;			}		}	}	lstExceptions->SetItem(item, 0, exDate);	lstExceptions->SetItem(item, 1, exTime);	lstExceptions->SetItem(item, 2, BoolToStr(true));	CheckChange();}

void dlgColumn::OnSelChangeTyp(wxCommandEvent &ev){	cbDatatype->GuessSelection(ev);	CheckLenEnable();	txtLength->Enable(isVarLen);	bool isSerial = (cbDatatype->GetValue() == wxT("serial") || cbDatatype->GetValue() == wxT("bigserial") || cbDatatype->GetValue() == wxT("smallserial"));	txtDefault->Enable(!isSerial);	CheckChange();}

void dlgDatabase::OnVarAdd(wxCommandEvent &ev){	wxString username = cbVarUsername->GetValue();	wxString name = cbVarname->GetValue();	wxString value;	if (chkValue->IsShown())		value = chkValue->GetValue() ? wxT("on") : wxT("off");	else		value = txtValue->GetValue().Strip(wxString::both);	if (value.IsEmpty())		value = wxT("DEFAULT");	if (!name.IsEmpty())	{		bool found = false;		long prevpos = -1;		for (long item = 0; item < lstVariables->GetItemCount(); item++)		{			if (name == lstVariables->GetText(item, 1))			{				if (username == lstVariables->GetText(item))				{					found = true;					lstVariables->SetItem(item, 2, value);				}				else				{					prevpos = item;				}			}		}		if (!found)		{			if (prevpos != -1)			{				lstVariables->InsertItem(prevpos, username, 1);				lstVariables->SetItem(prevpos, 1, name);				lstVariables->SetItem(prevpos, 2, value);			}			else			{				long pos = lstVariables->GetItemCount();				lstVariables->InsertItem(pos, username, 1);				lstVariables->SetItem(pos, 1, name);				lstVariables->SetItem(pos, 2, value);			}		}	}	dirtyVars = true;	CheckChange();}

void dlgGroup::OnUserAdd(wxCommandEvent &ev){    if (!readOnly)    {        int pos = lbUsersNotIn->GetSelection();        if (pos >= 0)        {            lbUsersIn->Append(lbUsersNotIn->GetString(pos));            lbUsersNotIn->Delete(pos);        }        CheckChange();    }}

void dlgJob::OnAddSchedule(wxCommandEvent &ev){	dlgSchedule schedule(&scheduleFactory, mainForm, NULL, job);	schedule.CenterOnParent();	schedule.SetConnection(connection);	if (schedule.Go(true) != wxID_CANCEL)	{		int pos = lstSchedules->AppendItem(scheduleFactory.GetIconId(), schedule.GetName(), schedule.GetComment());		wxString *scheduleSql = new wxString(schedule.GetInsertSql());		lstSchedules->SetItemData(pos, (long)scheduleSql);		CheckChange();	}}

void dlgSchedule::OnRemoveException(wxCommandEvent &ev){	if (lstExceptions->GetText(lstExceptions->GetFocusedItem(), 3) != wxEmptyString)	{		deleteExceptions.Add(lstExceptions->GetText(lstExceptions->GetFocusedItem(), 3));	}	lstExceptions->DeleteCurrentItem();	btnChangeException->Disable();	btnRemoveException->Disable();	CheckChange();}

void dlgForeignTable::OnMemberRemove(wxCommandEvent &ev){	long pos = lstMembers->GetSelection();	if (pos >= 0)	{		lstMembers->DeleteItem(pos);		memberTypes.RemoveAt(pos);		memberLengths.RemoveAt(pos);		memberPrecisions.RemoveAt(pos);		memberNotNulls.RemoveAt(pos);	}	CheckChange();}

void dlgSchedule::OnSelectAll(wxCommandEvent &ev, int origin){	bool check = false;	wxBitmapButton *btn;	wxCheckListBox *lb;	wxString tooltip;	switch (origin)	{		case 1:			btn = ((wxBitmapButton *)btnWeekdays);			lb = chkWeekdays;			break;		case 2:			btn = ((wxBitmapButton *)btnMonthdays);			lb = chkMonthdays;			break;		case 3:			btn = ((wxBitmapButton *)btnMonths);			lb = chkMonths;			break;		case 4:			btn = ((wxBitmapButton *)btnHours);			lb = chkHours;			break;		case 5:			btn = ((wxBitmapButton *)btnMinutes);			lb = chkMinutes;			break;		default:			return;			break;	}	for (unsigned int x = 0; x < lb->GetCount(); x++)	{		if (!lb->IsChecked(x))		{			check = true;			break;		}	}	for (unsigned int x = 0; x < lb->GetCount(); x++)	{		lb->Check(x, check);	}	CheckChange();}

void dlgUser::OnChangeSuperuser(wxCommandEvent &ev){    if (user && user->GetSuperuser() && !chkCreateUser->GetValue())    {        wxMessageDialog dlg(this,            _("Deleting a superuser might result in unwanted behaviour (e.g. when restoring the database)./nAre you sure?"),            _("Confirm superuser deletion"),                     wxICON_EXCLAMATION | wxYES_NO |wxNO_DEFAULT);        if (dlg.ShowModal() != wxID_YES)        {            chkCreateUser->SetValue(true);            return;        }    }    CheckChange();}