C++ wxVariant::IsNull方法代码示例

bool wxVariant::operator== (const wxVariant& variant) const
{
    if (IsNull() || variant.IsNull())
        return (IsNull() == variant.IsNull());

    return (GetData()->Eq(* variant.GetData()));
}

bool wxPGVariantToDouble( const wxVariant& variant, double* pResult )
{
    if ( variant.IsNull() )
        return false;

    wxString variantType = variant.GetType();

    if ( variantType == wxPG_VARIANT_TYPE_DOUBLE )
    {
        *pResult = variant.GetDouble();
        return true;
    }

    if ( variantType == wxPG_VARIANT_TYPE_LONG )
    {
        *pResult = (double)variant.GetLong();
        return true;
    }

    if ( variantType == wxLongLong_VariantType )
    {
        wxLongLong ll;
        ll << variant;
        *pResult = ll.ToDouble();
        return true;
    }

    if ( variantType == wxPG_VARIANT_TYPE_STRING )
        if ( variant.GetString().ToDouble(pResult) )
            return true;

    return false;
}

long wxPGVariantToInt( const wxVariant& variant, long defVal )
{
    if ( variant.IsNull() )
        return defVal;

    if ( variant.GetType() == wxS("long") )
        return variant.GetLong();

    if ( variant.GetType() == wxS("bool") )
        return variant.GetBool() ? 1 : 0;

    if ( variant.GetType() == wxS("wxLongLong") )
    {
        wxLongLong ll;
        ll << variant;
        if ( ll >= LONG_MAX )
            return LONG_MAX;
        else if ( ll <= LONG_MIN )
            return LONG_MIN;
        return ll.ToLong();
    }

    long l = defVal;

    if ( variant.GetType() == wxPG_VARIANT_TYPE_STRING )
        variant.GetString().ToLong(&l, 0);

    return l;
}

std::string ScalarSelectionDialog::GetValueString(const wxVariant& variant, std::type_index type, int precision)
{
	std::string result;

	if (!variant.IsNull()) {
		if (IsFloat(type)) {
			std::stringstream strstream;
			if (precision > 0) {
				strstream << std::setprecision(precision) << std::fixed << variant.GetDouble();
			}
			else {
				strstream << std::fixed << variant.GetDouble();
			}
			
			auto tmpStr = strstream.str();
			size_t last_not_zero = tmpStr.find_last_not_of('0');
			result = tmpStr.substr(0, last_not_zero == std::string::npos ? last_not_zero : last_not_zero+1);
		}
		else if (IsIntegral(type)) {
			result = std::to_string(variant.GetInteger());
		}
	}

	return result;
}

wxVariant::wxVariant(const wxVariant& variant)
    : wxObject()
{
    m_data = NULL;

    if (!variant.IsNull())
        Ref(variant);

    m_name = variant.m_name;
}

int wxGISGPGxObjectDomain::GetPosByValue(const wxVariant &oVal) const
{
    if(!oVal.IsNull())
    {
		wxFileName oName(oVal.GetString());
        for(size_t i = 0; i < m_asoData.size(); ++i)
        {
            wxGxObjectFilter* poFilter = GetFilter(i);
            if(poFilter)
            {
                if( oName.GetExt().IsSameAs(poFilter->GetExt(), false) || poFilter->GetExt().IsEmpty() )
                {
                    return i;
                }
            }
        }
    }
	return wxNOT_FOUND;
}

bool wxPGVariantToULongLong( const wxVariant& variant, wxULongLong_t* pResult )
{
    if ( variant.IsNull() )
        return false;

    wxString variantType = variant.GetType();

    if ( variantType == wxPG_VARIANT_TYPE_LONG )
    {
        *pResult = (unsigned long)variant.GetLong();
        return true;
    }

    if ( variantType == wxULongLong_VariantType )
    {
        // NOTE: << operator uses this functions, so we can't use it here
        *pResult = wxULongLongRefFromVariant(variant).GetValue();
        return true;
    }

    return false;
}

wxVariant wxAutomationObject::GetProperty(const wxString& property,
        const wxVariant& arg1, const wxVariant& arg2,
        const wxVariant& arg3, const wxVariant& arg4,
        const wxVariant& arg5, const wxVariant& arg6)
{
    const wxVariant** args = new const wxVariant*[6];
    int i = 0;
    if (!arg1.IsNull())
    {
        args[i] = & arg1;
        i ++;
    }
    if (!arg2.IsNull())
    {
        args[i] = & arg2;
        i ++;
    }
    if (!arg3.IsNull())
    {
        args[i] = & arg3;
        i ++;
    }
    if (!arg4.IsNull())
    {
        args[i] = & arg4;
        i ++;
    }
    if (!arg5.IsNull())
    {
        args[i] = & arg5;
        i ++;
    }
    if (!arg6.IsNull())
    {
        args[i] = & arg6;
        i ++;
    }
    wxVariant retVariant;
    if (!Invoke(property, DISPATCH_PROPERTYGET, retVariant, i, NULL, args))
    {
        retVariant.MakeNull();
    }
    delete[] args;
    return retVariant;
}

wxVariant wxAutomationObject::CallMethod(const wxString& member,
        const wxVariant& arg1, const wxVariant& arg2,
        const wxVariant& arg3, const wxVariant& arg4,
        const wxVariant& arg5, const wxVariant& arg6)
{
    const wxVariant** args = new const wxVariant*[6];
    int i = 0;
    if (!arg1.IsNull())
    {
        args[i] = & arg1;
        i ++;
    }
    if (!arg2.IsNull())
    {
        args[i] = & arg2;
        i ++;
    }
    if (!arg3.IsNull())
    {
        args[i] = & arg3;
        i ++;
    }
    if (!arg4.IsNull())
    {
        args[i] = & arg4;
        i ++;
    }
    if (!arg5.IsNull())
    {
        args[i] = & arg5;
        i ++;
    }
    if (!arg6.IsNull())
    {
        args[i] = & arg6;
        i ++;
    }
    wxVariant retVariant;
    if (!Invoke(member, DISPATCH_METHOD, retVariant, i, NULL, args))
    {
        retVariant.MakeNull();
    }
    delete[] args;
    return retVariant;
}

WXDLLEXPORT bool wxConvertVariantToOle(const wxVariant& variant, VARIANTARG& oleVariant)
{
    VariantInit(&oleVariant);
    if (variant.IsNull())
    {
        oleVariant.vt = VT_NULL;
        return true;
    }

    wxString type(variant.GetType());

    if (type == wxT("errorcode"))
    {
        wxVariantDataErrorCode* const
            ec = wxStaticCastVariantData(variant.GetData(),
                                         wxVariantDataErrorCode);
        oleVariant.vt = VT_ERROR;
        oleVariant.scode = ec->GetValue();
    }
    else if (type == wxT("currency"))
    {
        wxVariantDataCurrency* const
            c = wxStaticCastVariantData(variant.GetData(),
                                        wxVariantDataCurrency);
        oleVariant.vt = VT_CY;
        oleVariant.cyVal = c->GetValue();
    }
    else if (type == wxT("safearray"))
    {
        wxVariantDataSafeArray* const
            vsa = wxStaticCastVariantData(variant.GetData(),
                                          wxVariantDataSafeArray);
        SAFEARRAY* psa = vsa->GetValue();
        VARTYPE vt;

        wxCHECK(psa, false);
        HRESULT hr = SafeArrayGetVartype(psa, &vt);
        if ( FAILED(hr) )
        {
            wxLogApiError(wxS("SafeArrayGetVartype()"), hr);
            SafeArrayDestroy(psa);
            return false;
        }
        oleVariant.vt = vt | VT_ARRAY;
        oleVariant.parray = psa;
    }
    else if (type == wxT("long"))
    {
        oleVariant.vt = VT_I4;
        oleVariant.lVal = variant.GetLong() ;
    }
#if wxUSE_LONGLONG
    else if (type == wxT("longlong"))
    {
        oleVariant.vt = VT_I8;
        oleVariant.llVal = variant.GetLongLong().GetValue();
    }
#endif
    else if (type == wxT("char"))
    {
        oleVariant.vt=VT_I1;            // Signed Char
        oleVariant.cVal=variant.GetChar();
    }
    else if (type == wxT("double"))
    {
        oleVariant.vt = VT_R8;
        oleVariant.dblVal = variant.GetDouble();
    }
    else if (type == wxT("bool"))
    {
        oleVariant.vt = VT_BOOL;
        oleVariant.boolVal = variant.GetBool() ? VARIANT_TRUE : VARIANT_FALSE;
    }
    else if (type == wxT("string"))
    {
        wxString str( variant.GetString() );
        oleVariant.vt = VT_BSTR;
        oleVariant.bstrVal = wxConvertStringToOle(str);
    }
#if wxUSE_DATETIME
    else if (type == wxT("datetime"))
    {
        wxDateTime date( variant.GetDateTime() );
        oleVariant.vt = VT_DATE;

        SYSTEMTIME st;
        date.GetAsMSWSysTime(&st);

        SystemTimeToVariantTime(&st, &oleVariant.date);
    }
#endif
    else if (type == wxT("void*"))
    {
        oleVariant.vt = VT_DISPATCH;
        oleVariant.pdispVal = (IDispatch*) variant.GetVoidPtr();
    }
    else if (type == wxT("list"))
    {
        wxSafeArray<VT_VARIANT> safeArray;
        if (!safeArray.CreateFromListVariant(variant))
//.........这里部分代码省略.........

WXDLLEXPORT bool wxConvertVariantToOle(const wxVariant& variant, VARIANTARG& oleVariant)
{
    VariantInit(&oleVariant);
    if (variant.IsNull())
    {
        oleVariant.vt = VT_NULL;
        return true;
    }

    wxString type(variant.GetType());

    if (type == wxT("errorcode"))
    {
        wxVariantDataErrorCode* const
            ec = wxStaticCastVariantData(variant.GetData(),
                                         wxVariantDataErrorCode);
        oleVariant.vt = VT_ERROR;
        oleVariant.scode = ec->GetValue();
    }
    else if (type == wxT("currency"))
    {
        wxVariantDataCurrency* const
            c = wxStaticCastVariantData(variant.GetData(),
                                        wxVariantDataCurrency);
        oleVariant.vt = VT_CY;
        oleVariant.cyVal = c->GetValue();
    }
    else if (type == wxT("safearray"))
    {
        wxVariantDataSafeArray* const
            vsa = wxStaticCastVariantData(variant.GetData(),
                                          wxVariantDataSafeArray);
        SAFEARRAY* psa = vsa->GetValue();
        VARTYPE vt;

        wxCHECK(psa, false);
        HRESULT hr = SafeArrayGetVartype(psa, &vt);
        if ( FAILED(hr) )
        {
            wxLogApiError(wxS("SafeArrayGetVartype()"), hr);
            SafeArrayDestroy(psa);
            return false;
        }
        oleVariant.vt = vt | VT_ARRAY;
        oleVariant.parray = psa;
    }
    else if (type == wxT("long"))
    {
        oleVariant.vt = VT_I4;
        oleVariant.lVal = variant.GetLong() ;
    }
    // Original VC6 came with SDK too old to contain VARIANT::llVal declaration
    // and there doesn't seem to be any way to test for it as Microsoft simply
    // added it to the later version of oaidl.h without changing anything else.
    // So assume it's not present for VC6, even though it might be if an
    // updated SDK is used. In this case the user would need to disable this
    // check himself.
#if wxUSE_LONGLONG && !defined(__VISUALC6__)
    else if (type == wxT("longlong"))
    {
        oleVariant.vt = VT_I8;
        oleVariant.llVal = variant.GetLongLong().GetValue();
    }
#endif
    else if (type == wxT("char"))
    {
        oleVariant.vt=VT_I1;            // Signed Char
        oleVariant.cVal=variant.GetChar();
    }
    else if (type == wxT("double"))
    {
        oleVariant.vt = VT_R8;
        oleVariant.dblVal = variant.GetDouble();
    }
    else if (type == wxT("bool"))
    {
        oleVariant.vt = VT_BOOL;
        oleVariant.boolVal = variant.GetBool() ? VARIANT_TRUE : VARIANT_FALSE;
    }
    else if (type == wxT("string"))
    {
        wxString str( variant.GetString() );
        oleVariant.vt = VT_BSTR;
        oleVariant.bstrVal = wxConvertStringToOle(str);
    }
#if wxUSE_DATETIME
    else if (type == wxT("datetime"))
    {
        wxDateTime date( variant.GetDateTime() );
        oleVariant.vt = VT_DATE;

        SYSTEMTIME st;
        date.GetAsMSWSysTime(&st);

        SystemTimeToVariantTime(&st, &oleVariant.date);
    }
#endif
    else if (type == wxT("void*"))
    {
        oleVariant.vt = VT_DISPATCH;
//.........这里部分代码省略.........

WXDLLEXPORT bool wxConvertVariantToOle(const wxVariant& variant, VARIANTARG& oleVariant)
{
    VariantInit(&oleVariant);
    if (variant.IsNull())
    {
        oleVariant.vt = VT_NULL;
        return true;
    }

    wxString type(variant.GetType());


    if (type == wxT("long"))
    {
        oleVariant.vt = VT_I4;
        oleVariant.lVal = variant.GetLong() ;
    }
    else if (type == wxT("char"))
    {
        oleVariant.vt=VT_I1;            // Signed Char
        oleVariant.cVal=variant.GetChar();
    }
    else if (type == wxT("double"))
    {
        oleVariant.vt = VT_R8;
        oleVariant.dblVal = variant.GetDouble();
    }
    else if (type == wxT("bool"))
    {
        oleVariant.vt = VT_BOOL;
        oleVariant.boolVal = variant.GetBool();
    }
    else if (type == wxT("string"))
    {
        wxString str( variant.GetString() );
        oleVariant.vt = VT_BSTR;
        oleVariant.bstrVal = wxConvertStringToOle(str);
    }
#if wxUSE_DATETIME
    else if (type == wxT("datetime"))
    {
        wxDateTime date( variant.GetDateTime() );
        oleVariant.vt = VT_DATE;

        SYSTEMTIME st;
        date.GetAsMSWSysTime(&st);

        SystemTimeToVariantTime(&st, &oleVariant.date);
    }
#endif
    else if (type == wxT("void*"))
    {
        oleVariant.vt = VT_DISPATCH;
        oleVariant.pdispVal = (IDispatch*) variant.GetVoidPtr();
    }
    else if (type == wxT("list") || type == wxT("stringlist"))
    {
        oleVariant.vt = VT_VARIANT | VT_ARRAY;

        SAFEARRAY *psa;
        SAFEARRAYBOUND saBound;
        VARIANTARG *pvargBase;
        VARIANTARG *pvarg;
        int i, j;

        int iCount = variant.GetCount();

        saBound.lLbound = 0;
        saBound.cElements = iCount;

        psa = SafeArrayCreate(VT_VARIANT, 1, &saBound);
        if (psa == NULL)
            return false;

        SafeArrayAccessData(psa, (void**)&pvargBase);

        pvarg = pvargBase;
        for (i = 0; i < iCount; i++)
        {
            // copy each string in the list of strings
            wxVariant eachVariant(variant[i]);
            if (!wxConvertVariantToOle(eachVariant, * pvarg))
            {
                // memory failure:  back out and free strings alloc'ed up to
                // now, and then the array itself.
                pvarg = pvargBase;
                for (j = 0; j < i; j++)
                {
                    SysFreeString(pvarg->bstrVal);
                    pvarg++;
                }
                SafeArrayDestroy(psa);
                return false;
            }
            pvarg++;
        }

        SafeArrayUnaccessData(psa);

        oleVariant.parray = psa;
//.........这里部分代码省略.........

 virtual bool SetValue(const wxVariant& value)
 {
     return base::SetValue(value.IsNull() ? wxVariant((bool)false) : value);
 }

WXDLLEXPORT bool wxConvertVariantToOle(const wxVariant& variant, VARIANTARG& oleVariant)
{
    VariantInit(&oleVariant);
    if (variant.IsNull())
    {
        oleVariant.vt = VT_NULL;
        return true;
    }

    wxString type(variant.GetType());


    if (type == wxT("long"))
    {
        oleVariant.vt = VT_I4;
        oleVariant.lVal = variant.GetLong() ;
    }
    // Original VC6 came with SDK too old to contain VARIANT::llVal declaration
    // and there doesn't seem to be any way to test for it as Microsoft simply
    // added it to the later version of oaidl.h without changing anything else.
    // So assume it's not present for VC6, even though it might be if an
    // updated SDK is used. In this case the user would need to disable this
    // check himself.
#if wxUSE_LONGLONG && !defined(__VISUALC6__)
    else if (type == wxT("longlong"))
    {
        oleVariant.vt = VT_I8;
        oleVariant.llVal = variant.GetLongLong().GetValue();
    }
#endif
    else if (type == wxT("char"))
    {
        oleVariant.vt=VT_I1;            // Signed Char
        oleVariant.cVal=variant.GetChar();
    }
    else if (type == wxT("double"))
    {
        oleVariant.vt = VT_R8;
        oleVariant.dblVal = variant.GetDouble();
    }
    else if (type == wxT("bool"))
    {
        oleVariant.vt = VT_BOOL;
        oleVariant.boolVal = variant.GetBool() ? VARIANT_TRUE : VARIANT_FALSE;
    }
    else if (type == wxT("string"))
    {
        wxString str( variant.GetString() );
        oleVariant.vt = VT_BSTR;
        oleVariant.bstrVal = wxConvertStringToOle(str);
    }
#if wxUSE_DATETIME
    else if (type == wxT("datetime"))
    {
        wxDateTime date( variant.GetDateTime() );
        oleVariant.vt = VT_DATE;

        SYSTEMTIME st;
        date.GetAsMSWSysTime(&st);

        SystemTimeToVariantTime(&st, &oleVariant.date);
    }
#endif
    else if (type == wxT("void*"))
    {
        oleVariant.vt = VT_DISPATCH;
        oleVariant.pdispVal = (IDispatch*) variant.GetVoidPtr();
    }
    else if (type == wxT("list"))
    {
        wxSafeArrayHelper sah;

        if (!sah.Create(VT_VARIANT, variant.GetCount()))
            return false;

        for (size_t i = 0; i < variant.GetCount(); i++)
        {
            if (!sah.SetElement(i, variant[i]))
                return false;
        }

        oleVariant.vt = VT_VARIANT | VT_ARRAY;
        oleVariant.parray = sah.Detach();
    }
    else if (type == wxT("arrstring"))
    {
        wxArrayString strings(variant.GetArrayString());
        wxSafeArrayHelper sah;

        if (!sah.Create(VT_BSTR, strings.GetCount()))
            return false;

        for (size_t i = 0; i < strings.GetCount(); i++)
        {
            if (!sah.SetElement(i, strings[i]))
                return false;
        }

        oleVariant.vt = VT_BSTR | VT_ARRAY;
        oleVariant.parray = sah.Detach();
//.........这里部分代码省略.........