wpf创建用户控件（计时器控件）

在vs中新增用户控件

前台xaml如下代码：

<UserControl x:Class="Zh.SelfServiceEquipment.UI.ZhControls.CountDownTimeControl"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:local="clr-namespace:Zh.SelfServiceEquipment.UI.ZhControls"
             mc:Ignorable="d" 
             d:DesignHeight="50" d:DesignWidth="300"
             Loaded="UserControl_Loaded">
    <Grid>
        <StackPanel Orientation="Horizontal">
            <Label Content="倒计时" Foreground="White" FontSize="20" VerticalAlignment="Center"></Label>
            <Label Content="30" Foreground="Red" FontSize="25" VerticalAlignment="Center" x:Name="lblTime"></Label>
            <Label Content="秒" Foreground="White" FontSize="20" VerticalAlignment="Center"></Label>
        </StackPanel>
    </Grid>
</UserControl>

CS代码：

public partial class CountDownTimeControl : UserControl
    {
        public delegate void CountDownTimeOutEventHandler(object sender);
        public event CountDownTimeOutEventHandler OnCountDownTime;
        private System.Windows.Threading.DispatcherTimer dTime;//定义事件，在倒计时结束的时候进行调用
        public CountDownTimeControl()
        {
            InitializeComponent();
            StartCountdownTime();
        }
        private int _count;

        public int Count//定义时间，并将该时间的值赋值给前台页面
        {
            get { return _count; }
            set { _count = value; this.lblTime.Content = _count; }
        }
        public void StartCountdownTime() {
            dTime = new System.Windows.Threading.DispatcherTimer();
            dTime.Interval = new TimeSpan(0,0,1);
            dTime.Tick += DTime_Tick;
        }
        private void DTime_Tick(object sender, EventArgs e)
        {
            if (Count-- == 1)
            {
                this.dTime.Stop();
                if (OnCountDownTime!=null)
                {
                    this.OnCountDownTime(this);
                }
            }
        }
        private void UserControl_Loaded(object sender, RoutedEventArgs e)
        {
            dTime.Start();
        }
    }

接下来就是在MainWindow.xaml文件中对该控件进行引用

在前台页面命名空间写入

xmlns:zhControls="clr-namespace:Zh.SelfServiceEquipment.UI.ZhControls"

其中zhControls是随便定义的，Zh.SelfServiceEquipment.UI.ZhControls是项目中用户控件所在的命名空间

MainWindows.xaml前台代码如下

<Window x:Class="Zh.SelfServiceEquipment.UI.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:Zh.SelfServiceEquipment.UI"
        xmlns:zhControls="clr-namespace:Zh.SelfServiceEquipment.UI.ZhControls"
        mc:Ignorable="d"
        Title="MainWindow" Height="350" Width="525">
    <Grid Background="Black">
        <WrapPanel>
            <zhControls:CountDownTimeControl Count="10" OnCountDownTime="CountDownTimeControl_OnCountDownTime"></zhControls:CountDownTimeControl>
        </WrapPanel>
    </Grid>
</Window>

MainWindow.xaml.cs代码

public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }
        private void CountDownTimeControl_OnCountDownTime(object sender)
        {
            MessageBox.Show("倒计时结束");
        }
    }

大功告成，让我们看看运行结果