Timer.Tick 事件
本文内容
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。
当指定的计时器间隔已过去而且计时器处于启用状态时发生。
public:
event EventHandler ^ Tick;
public event EventHandler Tick;
member this.Tick : EventHandler
Public Custom Event Tick As EventHandler
下面的代码示例实现一个简单的间隔计时器,该计时器每隔五秒发出一次警报。 发生警报时, MessageBox 将显示警报已启动的次数的计数,并提示用户是否应继续运行计时器。
public ref class Class1
{
private:
static System::Windows::Forms::Timer^ myTimer = gcnew System::Windows::Forms::Timer;
static int alarmCounter = 1;
static bool exitFlag = false;
// This is the method to run when the timer is raised.
static void TimerEventProcessor( Object^ /*myObject*/, EventArgs^ /*myEventArgs*/ )
{
myTimer->Stop();
// Displays a message box asking whether to continue running the timer.
if ( MessageBox::Show( "Continue running?", String::Format( "Count is: {0}", alarmCounter ), MessageBoxButtons::YesNo ) == DialogResult::Yes )
{
// Restarts the timer and increments the counter.
alarmCounter += 1;
myTimer->Enabled = true;
}
else
{
// Stops the timer.
exitFlag = true;
}
}
public:
static void Main()
{
/* Adds the event and the event handler for the method that will
process the timer event to the timer. */
myTimer->Tick += gcnew EventHandler( TimerEventProcessor );
// Sets the timer interval to 5 seconds.
myTimer->Interval = 5000;
myTimer->Start();
// Runs the timer, and raises the event.
while ( !exitFlag )
{
// Processes all the events in the queue.
Application::DoEvents();
}
}
};
int main()
{
Class1::Main();
}
public class Class1 {
static System.Windows.Forms.Timer myTimer = new System.Windows.Forms.Timer();
static int alarmCounter = 1;
static bool exitFlag = false;
// This is the method to run when the timer is raised.
private static void TimerEventProcessor(Object myObject,
EventArgs myEventArgs) {
myTimer.Stop();
// Displays a message box asking whether to continue running the timer.
if(MessageBox.Show("Continue running?", "Count is: " + alarmCounter,
MessageBoxButtons.YesNo) == DialogResult.Yes) {
// Restarts the timer and increments the counter.
alarmCounter +=1;
myTimer.Enabled = true;
}
else {
// Stops the timer.
exitFlag = true;
}
}
public static int Main() {
/* Adds the event and the event handler for the method that will
process the timer event to the timer. */
myTimer.Tick += new EventHandler(TimerEventProcessor);
// Sets the timer interval to 5 seconds.
myTimer.Interval = 5000;
myTimer.Start();
// Runs the timer, and raises the event.
while(!exitFlag) {
// Processes all the events in the queue.
Application.DoEvents();
}
return 0;
}
}
Public Class Class1
Private Shared WithEvents myTimer As New System.Windows.Forms.Timer()
Private Shared alarmCounter As Integer = 1
Private Shared exitFlag As Boolean = False
' This is the method to run when the timer is raised.
Private Shared Sub TimerEventProcessor(myObject As Object, _
ByVal myEventArgs As EventArgs) _
Handles myTimer.Tick
myTimer.Stop()
' Displays a message box asking whether to continue running the timer.
If MessageBox.Show("Continue running?", "Count is: " & alarmCounter, _
MessageBoxButtons.YesNo) = DialogResult.Yes Then
' Restarts the timer and increments the counter.
alarmCounter += 1
myTimer.Enabled = True
Else
' Stops the timer.
exitFlag = True
End If
End Sub
Public Shared Sub Main()
' Adds the event and the event handler for the method that will
' process the timer event to the timer.
' Sets the timer interval to 5 seconds.
myTimer.Interval = 5000
myTimer.Start()
' Runs the timer, and raises the event.
While exitFlag = False
' Processes all the events in the queue.
Application.DoEvents()
End While
End Sub
End Class
Assert从 事件内部Tick对 Debug 类调用 方法可能无法按预期方式运行,因为显示断言对话框可能会导致 Windows 重复引发Tick事件。 建议不要在此事件中测试断言,而是改用 Write、 WriteIf、 WriteLine或 WriteLineIf 方法。
有关处理事件的详细信息,请参阅 处理和引发事件。
适用于
产品 | 版本 |
---|---|
.NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
Windows Desktop | 3.0, 3.1, 5, 6, 7, 8, 9, 10 |