mysql - VB.Net 列出 MySQL 中的所有用户并将它们分配给变量

Question

我这里有代码查询数据库以根据全名提供用户列表。问题是，当我将列表分配给一个变量时，稍后我将该变量分配给一个列表框，它只显示一个结果。有人可以帮我吗？

 Private ListofAllUsers As String

 Private Sub GetALLUserList()
        Dim UFullNameList As String

        If DataConnection.State = ConnectionState.Open Then

            Try

                QueryConnect = "SELECT * From users"
                CommandConnect = New MySqlCommand(QueryConnect, DataConnection)

                MyDataConnect = CommandConnect.ExecuteReader
                While MyDataConnect.Read()
                    UFullNameList = MyDataConnect.GetString("FullName")

                    ListofAllUsers = (UFullNameList)

                End While

                MyDataConnect.Close()

            Catch ex As MySqlException
                MsgBox(ex.Message, CType(MessageBoxIcon.Error, MsgBoxStyle), LoginUI.BrandMsgBox)
                DataConnection.Close()
            End Try

        Else

            Call GetSoftwareData()

            'Retry Again
            GetALLUserList()

        End If

现在我这样做它只显示一个有人可以帮助我吗？

   UListBox.Items.Add(ListofAllUsers)

Answer 1

将 ListofAllUsers 声明为 List (Of String)

在 while 循环中，只需将项目添加到字符串列表中即可。

我还添加了 using block 来正确处理连接。

Private ListofAllUsers As New List (Of String)
Private Sub GetALLUserList()
        Dim UFullNameList As String
        Dim QueryConnect = "SELECT * From users"
        'Add using block to properly dispose stuff.'
        Using DataConnection As New SqlConnection("your connection string"),
              cmd As New SqlCommand(QueryConnect, DataConnection)
            DataConnection.Open()
            Try
                Dim MyDataConnect As SqlDataReader = cmd.ExecuteReader()
                While MyDataConnect.Read()
                    UFullNameList = MyDataConnect.GetString("FullName")
                    'Add the item to the list of string here'
                    ListofAllUsers.Add(UFullNameList)
                End While
            Catch ex As MySqlException
                MsgBox(ex.Message, CType(MessageBoxIcon.Error, MsgBoxStyle), LoginUI.BrandMsgBox)
            End Try
            DataConnection .Close()
        End Using
End Sub

然后您可以将项目添加到列表框中，如下所示:

UListBox.Items.AddRange(ListofAllUsers)