在'If'语句vb .net中调用函数 [英] Call a function in an 'If' statement vb .net

问题描述

我想在'If'语句中调用一个函数，我之前已经完成了这个，但它有所不同。我之前就是这样做的：

I want to call a function in an 'If' statement, I have done this before but it was different. This is how I did it before:

If Not validatePhone(txtContactNumber.Text) Then 
......
End If

这对我来说很简单，因为我知道要放在括号中的内容，但我想调用一个检查数据库的函数：

That is straight forward for me because I know what to put in the brackets, but I want to call a function that checks that a database:

If Not checkDatabaseExists() Then
......
End If

我不知道这里的括号中有哪些参数。这是函数'checkDatabaseExists'的代码：

I do not know what parameters go into the brackets here. This is the code for the function 'checkDatabaseExists':

Public Shared Function checkDatabaseExists(ByVal server As String, ByVal database As String) As Boolean
        Dim conString As String = ("Data Source=.\SQLExpress;Initial Catalog=Visitors;Integrated Security=True;MultipleActiveResultSets=True")
        Dim cmdText As String = ("SELECT * FROM master.dbo.sysdatabases WHERE Name=Visitors")
        Dim databaseExists As Boolean = False
        Using sqlConnection As SqlConnection = New SqlConnection(conString)
            sqlConnection.Open()
            Using sqlCmd As SqlCommand = New SqlCommand(cmdText, sqlConnection)
                Using reader As SqlDataReader = sqlCmd.ExecuteReader
                    databaseExists = reader.HasRows
                End Using
            End Using
        End Using
        Return databaseExists
    End Function

有人能帮帮我吗？我知道这很简单，当我发现它是什么时我会自己踢，但不幸的是，我现在还没有线索。非常感谢所有这方面的帮助。



编辑：



我收到以下错误在'If'语句的checkDatabaseExists（）部分中有参数：



'未在公共共享函数checkDatabaseExists的参数database中指定参数（ByVal服务器为String，ByVal database As String）As Boolean'

Can anyone help me? I know it's something simple and I'll be kicking myself when I find out what it is but I haven't a clue at the moment unfortunately. All help with this matter would be greatly appreciated.



I get the following error without having parameters in the checkDatabaseExists() part of the 'If' statement:

'Argument not specified for parameter "database" of "Public Shared Function checkDatabaseExists(ByVal server As String, ByVal database As String) As Boolean" '

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