基本类型
官方：https://doc.qt.io/qt-5/qmlbasictypes.html
int, double, bool, string,var, variant, color, real, vector3d, url, time, rect, size, enumeration, font, date, point, list, action, alias
示例：
property real contentYOnFlickStarted: 0;
property var aboutDlg: null;
property color textColor: "green";ＱＭＬ与Ｃ++数据类型转换
