使用窗体（VB）中的单击事件调用函数 [英] Invoking a function with a click event in form (VB)

问题描述

我正在构建一个表格来将数字分数转换为字母等级，并且需要调用一个当我点击btnCalc按钮时调用的函数。表单上的输入字段标题为txtScore，输出字段为txtGrade。

下面的代码不起作用，我也得到这个错误：
'txtScore'是不明确的，因为在类中存在具有该名称的多种成员

我不确定可能是错的，已经经历了很多教程和文档，但似乎无法解决。有人可以帮忙吗？

 公共课程成绩
 
 Dim txtScore = Math.Round（txtScore ）
 
 Public Sub btnCalc_Click（sender As Object，e As EventArgs）Handle btnCalc.Click 
 GetLetterGrade（txtScore）
 End Sub 
 
 Public Function GetLetterGrade （ByVal dblGrade As Double）As String 
 If txtScore <= 59 Then 
 txtGrade.Text =F
 ElseIf txtScore <= 69 Then 
 txtGrade.Text = D
 ElseIf txtScore< = 79 Then 
 txtGrade.Text =C
 ElseIf txtScore< = 89然后
 txtGrade.Text =B
 ElseIf txtScore< = 100 Then 
 txtGrade.Text =A
 End If 
 
 End Function 
  
  Public Class GradeForma 
 
 Public Sub btnCalc_Click（sender As Object，e As EventArgs）Handle btnCalc.Click 
 GetLetterGrade（）
 End Sub 
 
 Public Function GetLetterGrade（）作为字符串
 
 Dim dblResult as Double = Math.Round（txtScore）
 
如果dblResult< = 59那么
 txtGrade.Text =F 
 ElseIf dblResult< = 69 Then 
 txtGrade.Text =D
 ElseIf dblResult< = 79然后
 txtGrade.Text =C
 ElseIf dblResult < = 89然后
 txtGrade.Text =B
 ElseIf dblResult< = 100 Then 
 txtGrade.Text =A
 End If 
 
结束功能
  
 
I am building a form to convert a number score into a letter grade and need to invoke a function that is called when I click on the "btnCalc" button.  The input field on the form is titled "txtScore" and the output field is "txtGrade".

The code below isn't working and I'm also getting this error: "
'txtScore' is ambiguous because multiple kinds of members with this name exist in class"

I'm not sure what could be wrong, I've gone through a lot tutorials and documentation but can't seem to resolve.  Would someone be able to help?
Public Class GradeForma

Dim txtScore = Math.Round(txtScore)

Public Sub btnCalc_Click(sender As Object, e As EventArgs) Handles btnCalc.Click
    GetLetterGrade(txtScore)
End Sub

Public Function GetLetterGrade(ByVal dblGrade As Double) As String
    If txtScore <= 59 Then
        txtGrade.Text = "F"
    ElseIf txtScore <= 69 Then
        txtGrade.Text = "D"
    ElseIf txtScore <= 79 Then
        txtGrade.Text = "C"
    ElseIf txtScore <= 89 Then
        txtGrade.Text = "B"
    ElseIf txtScore <= 100 Then
        txtGrade.Text = "A"
    End If

End Function

解决方案
You don't need to pass parameters around for this example, just pull out the value from txtScore when you need it in GetLetterGrade().  You likely don't need a class level variable at all - as you maybe don't need to hold onto the result?
Public Class GradeForma

    Public Sub btnCalc_Click(sender As Object, e As EventArgs) Handles btnCalc.Click
        GetLetterGrade()
    End Sub

    Public Function GetLetterGrade() As String

        Dim dblResult as Double = Math.Round(txtScore)

        If dblResult <= 59 Then
            txtGrade.Text = "F"
        ElseIf dblResult <= 69 Then
            txtGrade.Text = "D"
        ElseIf dblResult <= 79 Then
            txtGrade.Text = "C"
        ElseIf dblResult <= 89 Then
            txtGrade.Text = "B"
        ElseIf dblResult <= 100 Then
            txtGrade.Text = "A"
        End If

    End Function


                        
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