private void Create()
        {
            Channel m = new Channel();                                                    //实例化一个新的model
            ChannelEditViewModel evm = new ChannelEditViewModel(m, _testerService.Items); //实例化一个新的view model

            evm.DisplayName = "Channel-Create";
            evm.commandType = CommandType.Create;
            var ChannelViewInstance = new ChannelView();      //实例化一个新的view

            ChannelViewInstance.DataContext = evm;
            ChannelViewInstance.ShowDialog();                   //设置viewmodel属性
            if (evm.IsOK == true)
            {
                _channelService.SuperAdd(m);
            }
        }
        private void SaveAs()
        {
            Channel m = new Channel();                                                    //实例化一个新的model
            ChannelEditViewModel evm = new ChannelEditViewModel(m, _testerService.Items); //实例化一个新的view model

            evm.Name = _selectedItem.Name;
            //evm.Tester = _selectedItem.Tester;
            evm.Tester        = evm.AllTesters.SingleOrDefault(i => i.Id == _selectedItem.Tester.Id); //所以改用Id来找到List里的item
            evm.AssetUseCount = _selectedItem.AssetUseCount;
            evm.DisplayName   = "Channel-Save As";
            evm.commandType   = CommandType.SaveAs;
            var ChannelViewInstance = new ChannelView();      //实例化一个新的view

            ChannelViewInstance.DataContext = evm;
            ChannelViewInstance.ShowDialog();
            if (evm.IsOK == true)
            {
                _channelService.SuperAdd(m);
            }
        }