C# WPF基础之Timer

<Window x:Class="WpfApp2.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApp2"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Grid>
        <Button Content="打开" Name="btnCtrlOpen" Click="btnCtrlOpen_Click" HorizontalAlignment="Left" Margin="310,115,0,0" VerticalAlignment="Top" Width="75"/>
        <Button Content="关闭" Name="btnCtrlClose" Click="BtnCtrlClose_Click" HorizontalAlignment="Left" Margin="495,115,0,0" VerticalAlignment="Top" Width="75"/>
        <Button Content="设置" Name="btnCtrlSet" Click="BtnCtrlSet_Click" HorizontalAlignment="Left" Margin="415,200,0,0" VerticalAlignment="Top" Width="75"/>
        <Label Content="显示标签" Name="lblShow" HorizontalAlignment="Left" Margin="170,115,0,0" VerticalAlignment="Top"/>
    </Grid>
</Window>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Windows.Threading;

namespace WpfApp2
{
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    {
        DispatcherTimer mTimer;
        public MainWindow()
        {
            InitializeComponent();
            mTimer = new DispatcherTimer();
            mTimer.Interval = new TimeSpan(0,0,3);//定时间隔3秒
            mTimer.Tick += MTimer_Tick;//加载事件，敲tab键事件框架可以自己出来
        }

        private void MTimer_Tick(object sender, EventArgs e)
        {
            lblShow.Content = "定时器间隔到啦";
        }

        private void btnCtrlOpen_Click(object sender, RoutedEventArgs e)
        {
            mTimer.Start();
        }

        private void BtnCtrlClose_Click(object sender, RoutedEventArgs e)
        {
            mTimer.Stop();
            lblShow.Content = "定时器关闭啦";
        }

        private void BtnCtrlSet_Click(object sender, RoutedEventArgs e)
        {
            lblShow.Content = "被我改了";
        }
    }
}