获取数据库服务器日期和时间

• 下载 GetServerDateTime.zip - 71.0 KB

引言

这个小型应用程序展示了如何在您的应用程序中显示服务器的日期和时间。

背景

需求是：在客户端应用程序中显示数据库服务器的当前系统日期和时间。当客户端应用程序启动时，它会从远程服务器（数据库服务器）获取当前日期和时间，并使用计时器将其每秒递增一次。

使用代码

ServerDateTime 类的代码

Imports System.Data

Imports System.Data.SqlClient

Public Class ServerDateTime

Public dtServerDateTime As DateTime

Private Shared tmrLocalTimer As New System.Windows.Forms.Timer()

' Flag to check whether it is First time run. 

Dim IsFirstTime As Boolean = True

Public Sub TimerEventProcessor(ByVal myObject As Object, ByVal myEventArgs As EventArgs)

'Check whether it is First time run. 

' If yes then Get Server time and display it in the Label.

If IsFirstTime = True Then

Dim cmd As SqlCommand

Dim tmpConnection As SqlConnection

Dim strConnectionString As String

Try

' Read ConnectionString from Application Configuration file.

strConnectionString = System.Configuration.ConfigurationManager.AppSettings("ServerConnectionString")

tmpConnection = New SqlConnection(strConnectionString)

' Open the Connection

tmpConnection.Open()

' Initialize the Command object with commandText and SQLConnection

cmd = New SqlCommand("Select GetDate()", tmpConnection)

'Execute the query and return the Server Date Time

dtServerDateTime = cmd.ExecuteScalar

' Display the Server Date Time in the Label.

GetServerDateAndTime.lServerDateTime.Text = Format(dtServerDateTime, "dd/MM/yyyy hh:mm:ss tt")

' Set the Flag to False

IsFirstTime = False

Catch ex As Exception

MsgBox(ex.Message)

Finally

If tmpConnection.State = ConnectionState.Open Then

cmd = Nothing

tmpConnection.Close()

End If

End Try

Else

'Add one Second to the dtServerDateTime

dtServerDateTime = DateAdd(DateInterval.Second, 1, dtServerDateTime)

End If

tmrLocalTimer.Enabled = True

' Display the Server Date Time in the ToolStripStatusLabel of the MainForm

GetServerDateAndTime.lServerDateTime.Text = Format(dtServerDateTime, "dd/MM/yyyy hh:mm:ss tt")

End Sub

Public Sub GetServerDateTime()

AddHandler tmrLocalTimer.Tick, AddressOf TimerEventProcessor

' Sets the timer interval to 1 second.

tmrLocalTimer.Interval = 1000

tmrLocalTimer.Start()

End Sub

End Class