<Border BorderThickness="1" BorderBrush="Black">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="6*" />
            <RowDefinition />
        </Grid.RowDefinitions>
        <Grid Background="White">
            <Button
                Margin="5"
                HorizontalAlignment="Right"
                VerticalAlignment="Top"
                Background="White"
                BorderThickness="0"
                Click="Button_Click"
                Content=" × "
                FontSize="18" />
            <TextBlock
                x:Name="tbTitle"
                Margin="5"
                HorizontalAlignment="Left"
                VerticalAlignment="Top"
                FontSize="16"
                Text="TextBlock"
                TextWrapping="Wrap" />
            <TextBlock
                x:Name="tbContent"
                Margin="20,40,0,0"
                HorizontalAlignment="Left"
                VerticalAlignment="Top"
                FontSize="16"
                Text="TextBlock"
                TextWrapping="Wrap" />
        </Grid>
        <Grid Grid.Row="2" Background="#F0F0F0" />
    </Grid>
    </Border>

   class NotifyData
    {
        public string Title { get; set; }
        public string Content { get; set; }
    }

   public partial class MainWindow : Window
    {
        int i = 0;
        public static List<Window1> _dialogs = new List<Window1>();
        public MainWindow()
        {
            InitializeComponent();
        }
     
        private void Button_Click(object sender, RoutedEventArgs e)
        {
            i++;
            NotifyData data = new NotifyData();
            data.Title = "提示";       
            data.Content = "XXX余额不足，XXX余额不足，XXX余额不足，XXX余额不足" + i;
            Window1 dialog = new Window1();//new 一个通知  
            dialog.Closed += Dialog_Closed;
            dialog.TopFrom = GetTopFrom();
            dialog.DataContext = data;//设置通知里要显示的数据            
            dialog.Show();
            _dialogs.Add(dialog);
        }
        private void Dialog_Closed(object sender, EventArgs e)
        {
            var closedDialog = sender as Window1;
            _dialogs.Remove(closedDialog);
        }
        double GetTopFrom()
        {
            //屏幕的高度-底部TaskBar的高度。
            double topFrom = System.Windows.SystemParameters.WorkArea.Bottom - 10;
            bool isContinueFind = _dialogs.Any(o => o.TopFrom == topFrom);
            while (isContinueFind)
            {
                topFrom = topFrom - 160;//此处100是NotifyWindow的高 160-100剩下的10  是通知之间的间距
                isContinueFind = _dialogs.Any(o => o.TopFrom == topFrom);
            }
            if (topFrom <= 0)
                topFrom = System.Windows.SystemParameters.WorkArea.Bottom-10;
            return topFrom;
        }
    }

 public partial class Window1 : Window
    {
        public double TopFrom
        {
            get; set;
        }

        public Window1()
        {
            InitializeComponent();
            this.Loaded += NotificationWindow_Loaded;
        }

        private void NotificationWindow_Loaded(object sender, RoutedEventArgs e)
        {
           
           NotifyData data = this.DataContext as NotifyData;
            if (data != null)
            {
                tbContent.Text = data.Content;
                tbTitle.Text = data.Title;
            }
            Window1 self = sender as Window1;
            if (self!=null)
            {
                double right=SystemParameters.WorkArea.Right-10;//工作区最右边的值                        
                self.Top = TopFrom - 160;
                DoubleAnimation animation = new DoubleAnimation();
                animation.Duration = new Duration(TimeSpan.FromMilliseconds(500));
                animation.From = right;
                animation.To = right - self.ActualWidth;
                self.BeginAnimation(Window.LeftProperty, animation);

                Task.Factory.StartNew(delegate
                {
                    int seconds = 5;//通知持续5s后消失
                    System.Threading.Thread.Sleep(TimeSpan.FromSeconds(seconds));
                    //Invoke到主进程中去执行
                    this.Dispatcher.Invoke(delegate
                    {
                        animation = new DoubleAnimation();
                        animation.Duration = new Duration(TimeSpan.FromMilliseconds(500));
                        animation.Completed += (s, a) => { self.Close(); };//动画执行完毕，关闭当前窗体
                        animation.From = right - self.ActualWidth;
                        animation.To = right;//通知从左往右收回
                        self.BeginAnimation(Window.LeftProperty, animation);
                    });
                });
            }
        }
        private void Button_Click(object sender, RoutedEventArgs e)
        {
            double right = SystemParameters.WorkArea.Right;
            DoubleAnimation animation = new DoubleAnimation();
            animation.Duration = new Duration(TimeSpan.FromMilliseconds(500));
            animation.Completed += (s, a) => { this.Close(); };
            animation.From = right - this.ActualWidth;
            animation.To = right;
            this.BeginAnimation(Window.LeftProperty, animation);
        }
    }