快速檢查Sql Server是否可以連線

 參考引用:[C#]快速檢查Sql Server是否可以連線

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Imports System.Diagnostics

Imports System.Net.Sockets

Imports System.Threading

Public Class Form4

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click

        Dim ip = "192.168.1.10" 'SQL Server主機的IP位址。

        Dim port = 1433 'SQL Server的port預設是1433。

        Dim sw As Stopwatch = New Stopwatch()

        sw.Start()

        Dim isConnection = TestConn(ip, port)

        sw.[Stop]()

        Dim message = String.Empty

        If isConnection Then

            message = "連線成功。 經過{0}秒。"

        Else

            message = "連線失敗了! 經過{0}秒!"

        End If

        Dim t = sw.ElapsedMilliseconds / 1000.0

        MessageBox.Show(String.Format(message, t))

    End Sub

    Public Function TestConn(ip As String, port As Integer) As Boolean

        Try

            Using tc As TcpClient = New TcpClient()

                Dim result As IAsyncResult = tc.BeginConnect(ip, port, Nothing, Nothing)

                Dim start = Date.Now

                Do

                    SpinWait.SpinUntil(Function() False, 100)

                    If result.IsCompleted Then Exit Do

                Loop While Date.Now.Subtract(start).TotalSeconds < 0.3

                If result.IsCompleted Then

                    tc.EndConnect(result)

                    Return True

                End If

                tc.Close()

                If Not result.IsCompleted Then

                    Return False

                End If

            End Using

        Catch ex As Exception

            Console.WriteLine(ex.Message)

            Throw

        End Try

        Return False

    End Function

End Class