private void Create()
        {
            Tester m = new Tester();                              //实例化一个新的model
            TesterEditViewModel evm = new TesterEditViewModel(m); //实例化一个新的view model

            evm.DisplayName = "Tester-Create";
            var TesterViewInstance = new TesterView();      //实例化一个新的view

            TesterViewInstance.DataContext = evm;
            TesterViewInstance.ShowDialog();                   //设置viewmodel属性
            if (evm.IsOK == true)
            {
                _testerService.SuperAdd(m);
            }
        }
        private void SaveAs()
        {
            Tester m = new Tester();                              //实例化一个新的model
            TesterEditViewModel evm = new TesterEditViewModel(m); //实例化一个新的view model

            evm.Manufacturer = _selectedItem.Manufacturer;
            evm.Name         = _selectedItem.Name;
            evm.DisplayName  = "Tester-Save As";
            var TesterViewInstance = new TesterView();      //实例化一个新的view

            TesterViewInstance.DataContext = evm;
            TesterViewInstance.ShowDialog();
            if (evm.IsOK == true)
            {
                _testerService.SuperAdd(m);
            }
        }