private void bt2_Click(object sender, RoutedEventArgs e)
{
ChatCline w = new ChatCline();
w.Owner = this;
w.Closed += (sendObj, args) => this.Activate();
w.Show();
}
private void StartWindow(string userName, int left, int top)
{
ChatCline w = new ChatCline();
w.Left = left;
w.Top = top;
w.UserName = userName;
w.Owner = this;
w.Closed += (sender, e) => this.Activate();//关闭子窗体时激活父窗体
w.Show();
}