private void Button_Click(object sender, RoutedEventArgs e)
        {
            Window2 w2 = new Window2(this.Top, this.Left);//this.Top,this.Left 作用是将当前父窗体的位置传给子窗体
           
            if (w2.ShowDialog()==true)
            {
                text1.Text = w2.name;
            }
        }
    }

  public string name;
        public Window2(double x,double y)
        {
            InitializeComponent();
            //启用‘Manual’属性后，可以手动设置窗体的显示位置
            this.WindowStartupLocation = WindowStartupLocation.Manual;
            this.Top = x;
            this.Left = y;
            //如需手动绑定事件，如下
　　　　　　  this.but1.AddHandler(Button.ClickEvent,new RoutedEventHandler(OkButton_Click));
        }

        private void but1_Click(object sender, RoutedEventArgs e)
        {
            name = "hlr";
            this.DialogResult = true;//必须设置，否则无法回传
        }

var item = this.DataGrid.SelectedItem;
if (item != null)
{
    this.DialogResult = true;
}

#region 信息检索命令
        private RelayCommand _SearchCommand;

        public RelayCommand SearchCommand
        {
            get
            {
                return _SearchCommand
                    ?? (_SearchCommand = new RelayCommand(ExecuteSearchCommand));
            }
        }

        /// <summary>
        /// 检索命令逻辑
        /// </summary>
        /// <param name="obj"></param>
        private void ExecuteSearchCommand(object obj)//object obj
        { 
            AddDialog v = new AddDialog();
            v.Closed += v_Closed;
            v.ShowDialog();
        }
        private void v_Closed(object sender, EventArgs e)
        {
            var frm = (AddDialog)sender;
            var item = (ModelAdd)frm.DataGrid.SelectedItem;
            if (item != null)
            {
                var id = item.ID;
            }
        }
        #endregion