Timer 构造函数
定义
重要
一些信息与预发行产品相关,相应产品在发行之前可能会进行重大修改。 对于此处提供的信息,Microsoft 不作任何明示或暗示的担保。
初始化 Timer 类的新实例。
重载
Timer() |
初始化 Timer 类的新实例,并将所有属性设置为初始值。 |
Timer(Double) | |
Timer(TimeSpan) |
Timer()
- Source:
- Timer.cs
- Source:
- Timer.cs
- Source:
- Timer.cs
初始化 Timer 类的新实例,并将所有属性设置为初始值。
public:
Timer();
public Timer ();
Public Sub New ()
示例
以下示例实例化一个 Timer 对象,该 Timer.Elapsed 对象每两秒 (2000 毫秒) 触发一次事件,为事件设置事件处理程序,并启动计时器。 事件处理程序会在每次引发属性时显示该属性的值 ElapsedEventArgs.SignalTime 。
using namespace System;
using namespace System::Timers;
public ref class Example
{
private:
static System::Timers::Timer^ aTimer;
public:
static void Demo()
{
// Create a timer and set a two second interval.
aTimer = gcnew System::Timers::Timer();
aTimer->Interval = 2000;
// Hook up the Elapsed event for the timer.
aTimer->Elapsed += gcnew System::Timers::ElapsedEventHandler(Example::OnTimedEvent);
// Have the timer fire repeated events (true is the default)
aTimer->AutoReset = true;
// Start the timer
aTimer->Enabled = true;
Console::WriteLine("Press the Enter key to exit the program at any time... ");
Console::ReadLine();
}
private:
static void OnTimedEvent(Object^ source, System::Timers::ElapsedEventArgs^ e)
{
Console::WriteLine("The Elapsed event was raised at {0}", e->SignalTime);
}
};
int main()
{
Example::Demo();
}
// The example displays output like the following:
// Press the Enter key to exit the program at any time...
// The Elapsed event was raised at 5/20/2015 8:48:58 PM
// The Elapsed event was raised at 5/20/2015 8:49:00 PM
// The Elapsed event was raised at 5/20/2015 8:49:02 PM
// The Elapsed event was raised at 5/20/2015 8:49:04 PM
// The Elapsed event was raised at 5/20/2015 8:49:06 PM
using System;
using System.Timers;
public class Example
{
private static Timer aTimer;
public static void Main()
{
// Create a timer and set a two second interval.
aTimer = new System.Timers.Timer();
aTimer.Interval = 2000;
// Hook up the Elapsed event for the timer.
aTimer.Elapsed += OnTimedEvent;
// Have the timer fire repeated events (true is the default)
aTimer.AutoReset = true;
// Start the timer
aTimer.Enabled = true;
Console.WriteLine("Press the Enter key to exit the program at any time... ");
Console.ReadLine();
}
private static void OnTimedEvent(Object source, System.Timers.ElapsedEventArgs e)
{
Console.WriteLine("The Elapsed event was raised at {0}", e.SignalTime);
}
}
// The example displays output like the following:
// Press the Enter key to exit the program at any time...
// The Elapsed event was raised at 5/20/2015 8:48:58 PM
// The Elapsed event was raised at 5/20/2015 8:49:00 PM
// The Elapsed event was raised at 5/20/2015 8:49:02 PM
// The Elapsed event was raised at 5/20/2015 8:49:04 PM
// The Elapsed event was raised at 5/20/2015 8:49:06 PM
open System.Timers
let onTimedEvent source (e: ElapsedEventArgs) =
printfn $"The Elapsed event was raised at {e.SignalTime}"
// Create a timer and set a two second interval.
let aTimer = new Timer()
aTimer.Interval <- 2000
// Hook up the Elapsed event for the timer.
aTimer.Elapsed.AddHandler onTimedEvent
// Have the timer fire repeated events (true is the default)
aTimer.AutoReset <- true
// Start the timer
aTimer.Enabled <- true
printfn "Press the Enter key to exit the program at any time... "
stdin.ReadLine() |> ignore
// The example displays output like the following:
// Press the Enter key to exit the program at any time...
// The Elapsed event was raised at 5/20/2015 8:48:58 PM
// The Elapsed event was raised at 5/20/2015 8:49:00 PM
// The Elapsed event was raised at 5/20/2015 8:49:02 PM
// The Elapsed event was raised at 5/20/2015 8:49:04 PM
// The Elapsed event was raised at 5/20/2015 8:49:06 PM
Imports System.Timers
Public Module Example
Private aTimer As Timer
Public Sub Main()
' Create a timer and set a two second interval.
aTimer = New System.Timers.Timer()
aTimer.Interval = 2000
' Hook up the Elapsed event for the timer.
AddHandler aTimer.Elapsed, AddressOf OnTimedEvent
' Have the timer fire repeated events (true is the default)
aTimer.AutoReset = True
' Start the timer
aTimer.Enabled = True
Console.WriteLine("Press the Enter key to exit the program at any time... ")
Console.ReadLine()
End Sub
Private Sub OnTimedEvent(source As Object, e As System.Timers.ElapsedEventArgs)
Console.WriteLine("The Elapsed event was raised at {0}", e.SignalTime)
End Sub
End Module
' The example displays output like the following:
' Press the Enter key to exit the program at any time...
' The Elapsed event was raised at 5/20/2015 8:48:58 PM
' The Elapsed event was raised at 5/20/2015 8:49:00 PM
' The Elapsed event was raised at 5/20/2015 8:49:02 PM
' The Elapsed event was raised at 5/20/2015 8:49:04 PM
' The Elapsed event was raised at 5/20/2015 8:49:06 PM
注解
下表显示了 实例 Timer的初始属性值。
属性 | 初始值 |
---|---|
AutoReset | true |
Enabled | false |
Interval | 100 毫秒 |
SynchronizingObject | 空引用(在 Visual Basic 中为 Nothing )。 |
另请参阅
适用于
Timer(Double)
- Source:
- Timer.cs
- Source:
- Timer.cs
- Source:
- Timer.cs
public:
Timer(double interval);
public Timer (double interval);
new System.Timers.Timer : double -> System.Timers.Timer
Public Sub New (interval As Double)
参数
- interval
- Double
事件之间经过的时间(以毫秒为单位)。 该值必须大于零且小于或等于 Int32.MaxValue。
例外
参数的值 interval
小于或等于零,或大于 Int32.MaxValue。
示例
以下示例实例化一个 Timer 对象,该 Timer.Elapsed 对象每两秒 (2000 毫秒) 触发一次事件,为事件设置事件处理程序,并启动计时器。 事件处理程序会在每次引发属性时显示该属性的值 ElapsedEventArgs.SignalTime 。
using System;
using System.Threading.Tasks;
using System.Timers;
class Example
{
static void Main()
{
Timer timer = new Timer(1000);
timer.Elapsed += async ( sender, e ) => await HandleTimer();
timer.Start();
Console.Write("Press any key to exit... ");
Console.ReadKey();
}
private static Task HandleTimer()
{
Console.WriteLine("\nHandler not implemented..." );
throw new NotImplementedException();
}
}
// The example displays output like the following:
// Press any key to exit...
// Handler not implemented...
//
// Unhandled Exception: System.NotImplementedException: The method or operation is not implemented.
// at Example.HandleTimer()
// at Example.<<Main>b__0>d__2.MoveNext()
// --- End of stack trace from previous location where exception was thrown ---
// at System.Runtime.CompilerServices.AsyncMethodBuilderCore.<>c__DisplayClass2.<ThrowAsync>b__5(Object state)
// at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
// at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
// at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
// at System.Threading.ThreadPoolWorkQueue.Dispatch()
open System
open System.Threading.Tasks
open System.Timers
let handleTimer () =
printfn "\nHandler not implemented..."
raise (NotImplementedException()): Task
let timer = new Timer 1000
timer.Elapsed.AddHandler(fun sender e -> task { do! handleTimer () } |> ignore)
timer.Start()
printf "Press any key to exit... "
Console.ReadKey() |> ignore
// The example displays output like the following:
// Press any key to exit...
// Handler not implemented...
//
// Unhandled Exception: System.NotImplementedException: The method or operation is not implemented.
// at Example.HandleTimer()
// at Example.<<Main>b__0>d__2.MoveNext()
// --- End of stack trace from previous location where exception was thrown ---
// at System.Runtime.CompilerServices.AsyncMethodBuilderCore.<>c__DisplayClass2.<ThrowAsync>b__5(Object state)
// at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
// at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
// at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
// at System.Threading.ThreadPoolWorkQueue.Dispatch()
Imports System.Threading.Tasks
Imports System.Timers
Public Module Example
Public Sub Main()
Dim timer As New Timer(1000)
AddHandler timer.Elapsed, AddressOf Example.HandleTimer
'timer.Elapsed = Async ( sender, e ) => await HandleTimer()
timer.Start()
Console.Write("Press any key to exit... ")
Console.ReadKey()
End Sub
Private Async Sub HandleTimer(sender As Object, e As EventArgs)
Await Task.Run(Sub()
Console.WriteLine()
Console.WriteLine("Handler not implemented..." )
Throw New NotImplementedException()
End Sub)
End Sub
End Module
' The example displays output like the following:
' Press any key to exit...
' Handler not implemented...
'
' Unhandled Exception: System.NotImplementedException: The method or operation is not implemented.
' at Example._Lambda$__1()
' at System.Threading.Tasks.Task.Execute()
' --- End of stack trace from previous location where exception was thrown ---
' at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
' at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
' at Example.VB$StateMachine_0_HandleTimer.MoveNext()
' --- End of stack trace from previous location where exception was thrown ---
' at System.Runtime.CompilerServices.AsyncMethodBuilderCore.<>c__DisplayClass2.<ThrowAsync>b__5(Object state)
' at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
' at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
' at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
' at System.Threading.ThreadPoolWorkQueue.Dispatch()
注解
此构造函数设置 Interval 新计时器实例的 属性,但不启用计时器。