Question

我的函数应返回一些值：

Public Function vratiTvrtke(ByVal hwid As String)
    Dim hardware As String = hwid
    Dim result = New List(Of String)()
    Try
        ManageConnection(False, konekcija) 'Open connection'
        Dim strQuery As String = "SELECT tvrtke_naziv, dabase FROM info.tvrtke;"
        Dim SqlCmd As New MySqlCommand(strQuery, dbCon)
        Dim reader As MySqlDataReader = SqlCmd.ExecuteReader()
        While reader.Read()

        End While
        reader.Close()
        Return result
    Catch ex As MySqlException
        Console.WriteLine("Error: " & ex.ToString())
        Return Nothing
    Finally
        ManageConnection(True, konekcija) 'Close connection
    End Try
End Function

从上面的函数返回的数据我应该做一个菜单：

 Public Function pripremiSucelje()

    Dim barmanager1 As New BarManager
    Dim barButtonItem = New BarButtonItem()
    barButtonItem.Content = [tvrtke_naziv]
    barButtonItem.Name = [dabase]
    Tvrtka.Items.Add(barButtonItem)
End Function

问题是，在第二个功能中，我应该为每个＆＃34;实现一个＆＃34;循环，因为第一个函数将返回多行。

我如何实现这一目标？

Answer 1

更改您的函数以将数据添加到此类的列表中：

Public Class ReturnList
    Public Property tvrtke_naziv As string
    Public Property dabase As string
End class

这里是将结果输入列表的函数：

Public Sub vratiTvrtke(ByVal hwid As String)
    Dim hardware As String = hwid
    Dim result = New List(Of ReturnList)
    Try
        ManageConnection(False, konekcija) 'Open connection'
        Dim strQuery As String = "SELECT tvrtke_naziv, dabase FROM info.tvrtke;"
        Dim SqlCmd As New MySqlCommand(strQuery, dbCon)
        Dim reader As MySqlDataReader = SqlCmd.ExecuteReader()
        While reader.Read()
            Dim TempResult As New ReturnList
            TempResult.tvrtke_naziv = reader(0)
            TempResult.dabase =  reader(1)
            result.Add (TempResult)
        End While
        reader.Close()
    Catch ex As MySqlException
        Console.WriteLine("Error: " & ex.ToString())
    Finally
        ManageConnection(True, konekcija) 'Close connection
    End Try
    pripremiSucelje(result)
End Function

然后只需添加For Each循环：

Public Function pripremiSucelje(ByVal MyList As List(Of ReturnList)
    For Each item As ReturnList in MyList
        Dim barmanager1 As New BarManager
        Dim barButtonItem = New BarButtonItem()
        barButtonItem.Content = item.tvrtke_naziv
        barButtonItem.Name = item.dabase
        Tvrtka.Items.Add(barButtonItem)
    Next
End Function

VB.NET从数据库中获取值并创建下拉菜单

1 个答案: