Visual Basic Timer

In visual basic, Timer component is useful to raise an event repeatedly in our application based on the specified interval of time.

 

The timer component is available with System.Timers namespace. So, to work with the timer component in our application to raise an event after a set of interval we need to import the System.Timers namespace.

 

Following is the example of defining the timer object that raises an elapsed event after a set of interval in visual basic.

 

' Create timer

Dim timer As Timer = New Timer()

timer.Interval = 2000

AddHandler timer.Elapsed, AddressOf TimerEvent

timer.AutoReset = True

timer.Enabled = True

If you observe the above code, we created a timer object by using the Timer class. Here, the Interval property is used to specify the time interval to raise an Elapsed event (TimerEvent) and the Enabled property is used to specify whether the timer object should raise an Elapsed event or not.

 

The AutoReset property is used to configure the timer object to raise an elapsed event repeatedly at the specified interval of time defined by the Interval property.

 

In case, if we want to raise the Elapsed event only once after the specified interval has elapsed, then we need to set the AutoReset property to false.

Visual Basic Timer Properties

Following table lists some of the most commonly used properties of Timer class in visual basic.

 

PropertyDescription
AutoReset It is useful to get or set whether the Timer should raise the Elapsed event only once (false) or repeatedly (true).
CanRaiseEvents It will return a value which indicate whether the component can raise an event or not.
DesignMode It will return a value which indicate whether the component is in design mode or not.
Enabled It is useful to get or set a value to indicate whether the Timer should raise the Elapsed event or not.
Interval It is useful to get or set the interval in milliseconds at which to raise the Elapsed event.

Visual Basic Timer Methods

Following table lists some of the most commonly used methods of Timer class in visual basic.

 

MethodDescription
Start() It is useful to start raise the Elapsed event by setting Enabled to true.
Stop() It will stop raising the Elapsed event by setting Enabled to false.
Close() It is useful to release the resources that are used by the Timer.
Dispose() It is useful to release all the resources used by the Component.
MemberwiseClone() It is useful to create a shallow copy of the current object.
GetType() It is useful to get the type of current instance.

Visual Basic Timer Example

Following is the example of using Timer class in visual basic to execute the Elapsed events repeatedly at specified interval of time.

 

Imports System.Timers

 

ModuleModule1

    Sub Main(ByVal args As String())

        Console.WriteLine("Present Enter Key to Exit the Application")

        ' Create timer

        Dim timer As Timer = New Timer()

        timer.Interval = 2000

        AddHandler timer.Elapsed, AddressOf TimerEvent

        timer.AutoReset = True

        timer.Enabled = True

        Console.ReadLine()

    End Sub

    ' Elapsed Event

    Private Sub TimerEvent(ByVal source As Object, ByVal e As ElapsedEventArgs)

        Console.WriteLine("Event Raised at {0:HH:mm:ss.fff}", e.SignalTime)

    End Sub

End Module

If you observe the above example, we imported System.Timers namespace to create a timer object by using Timer class. Here, we used Interval property to specify the time interval to raise an Elapsed event (TimerEvent) and the Enabled property to specify whether the timer object should raise an Elapsed event or not.

 

When we execute the above visual basic program, we will get the result like as shown below.

 

Present Enter Key to Exit the Application

 

Event Raised at 07:48:49.274

Event Raised at 07:48:51.275

Event Raised at 07:48:53.275

Event Raised at 07:48:55.275

If you observe the result, for every 2 seconds the Elapsed event (TimerEvent) is raising and executing the elapsed event code.

 

This is how we can use the timer object to raise an event repeatedly at the specified interval of time based on our requirements.

 
 
 

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