Question

出于某种原因，我的messageBox没有出现！有人可以帮助我：

代码：

item = InputBox("What is the item?", "InputBox Test", "Type the item here.")
If item = "shoe" Then
    Dim connStr As String = ""
    Dim connection As New MySqlConnection(connStr)
    Dim READER As MySqlDataReader
    connection.Open()
    Dim Query As String
    Query = "UPDATE table set item = noOfItems+1 where username= '" & Login.txtusername.Text & "'"
    COMMAND = New MySqlCommand(Query, connection)
    READER = COMMAND.ExecuteReader
    If (READER.Read() = True) Then
        Query = "select * from table where username= '" & Login.txtusername.Text & " '"
        Dim noOfItems As Integer
        Dim username As String
        noOfItems = READER("noOfItems")
        username = READER("username")
        MessageBox.Show(username & "- The number of items you have is: " & noOfItems)
    End If
Else
    MsgBox("Unlucky, Incorrect item. Please see hints. Your score still remains the same")

提前致谢：）

Answer 1

Dim item As Object
Dim Command As MySqlCommand
Dim READER As MySqlDataReader
Dim connection As MySqlConnection
Dim Query As String
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    Try
        item = InputBox("What is the item?", "InputBox Test", "Type the item here.")
        If item = "shoe" Then
            Dim connStr As String = ""
            Dim connection As New MySqlConnection(connStr)
            connection.Open()
            Query = "select * from table where username= '" & txtusername.Text & " '"
            READER = Command.ExecuteReader
            If READER.HasRows Then
                Dim noOfItems As Integer
                Dim username As String
                noOfItems = READER("noOfItems") + 1
                username = READER("username")
                Query = "UPDATE table set item = '" & noOfItems & "' where username= '" & txtusername.Text & "'"
                Command = New MySqlCommand(Query, connection)
                Command.ExecuteNonQuery()
                MessageBox.Show(username & "- The number of items you have is: " & noOfItems)
            End If
        Else
            MsgBox("Unlucky, Incorrect item. Please see hints. Your score still remains the same")
        End If
        connection.close()
    Catch ex As Exception
        MessageBox.Show("Error")
    End Try
End Sub

visual basic - MessageBox没有出现

1 个答案: