HOW TO:可视化配置数据源连接字符串(二)

Author:水如烟 

HOW TO:可视化配置数据源连接字符串(一)
  

文件AdoConnectionDialog.vb

Option Strict Off
Namespace uDataNamespace uData.ConnectionUI
    Public Class AdoConnectionDialogClass AdoConnectionDialog

        Private gConnectionString As String = Nothing

        Public Property ConnectionString()Property ConnectionString() As String
            Get
                Return gConnectionString
            End Get

            Set(ByVal value As String)
                gConnectionString = value
            End Set
        End Property


        Public Function ShowDialog()Function ShowDialog() As System.Windows.Forms.DialogResult

            Return ShowDialog(Nothing)
        End Function

        Public Function ShowDialog()Function ShowDialog(ByVal owner As System.Windows.Forms.Form) As System.Windows.Forms.DialogResult
            Dim mResult As System.Windows.Forms.DialogResult = System.Windows.Forms.DialogResult.OK

            Dim AdoConnection As Object
            Dim DataLinks As Object = CreateObject("DataLinks")

            If owner Is Nothing Then
                DataLinks.hWnd = IntPtr.Zero
            Else
                DataLinks.hWnd = owner.Handle
            End If

            If gConnectionString Is Nothing OrElse gConnectionString.Trim.Equals(String.Empty) Then '新建字符串
                AdoConnection = DataLinks.PromptNew()
                mResult = IIf(Not AdoConnection Is Nothing, System.Windows.Forms.DialogResult.OK, System.Windows.Forms.DialogResult.Cancel)

            Else '编辑已有字符串
                AdoConnection = CreateObject("ADODB.Connection")
                AdoConnection.ConnectionString = gConnectionString
                mResult = IIf(DataLinks.PromptEdit(AdoConnection), System.Windows.Forms.DialogResult.OK, System.Windows.Forms.DialogResult.Cancel)
            End If

            If mResult = System.Windows.Forms.DialogResult.OK Then
                gConnectionString = AdoConnection.ConnectionString
            End If

            AdoConnection = Nothing
            DataLinks = Nothing

            Return mResult
        End Function
    End Class
End Namespace

上面的类可视化生成或编辑一个AdoConnection的数据源连接字符串.测试代码如下(各位使用时注意命名空间):

    Dim t As New LzmTW.uData.ConnectionUI.AdoConnectionDialog
    Private Sub Button2_Click()Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        If t.ShowDialog(Me) = Windows.Forms.DialogResult.OK Then
            Console.WriteLine(t.ConnectionString)
        Else
            Console.WriteLine("Cancel")
        End If
    End Sub

下面的处理关键是我们常用到的OleDbConnection、OdbcConnection、SqlConnection的ConnectionString与AdoConnection的ConnectionString如何相互转换。这好象并不简单，看来还得掌握一些AdoConnection的相关特性才行。
还得分节。下一节，AdoConnection的连接字符串有关特性