Vb.net Visual Basic函数的变量声明中出错

我对编码还不熟悉，刚把专业从EE转到IT——在Visual Basic函数方面遇到了问题。我认为我的错误在函数的变量声明中，但我不能完全确定。该程序应该将住院天数乘以我声明的常数=350，并将所有杂项费用加到该数字上，但我返回0。有人能帮我找出错误吗

Visual Basic代码：

Const decStay_Rate As Decimal = 350

    Private decLength As Integer
    Private decMedication As Decimal
    Private decSurgical As Decimal
    Private decLab As Decimal
    Private decPhysical As Decimal
    Private decTotalStayPrice As Decimal
    Private decTotalMiscCharges As Decimal

    Private decTotal As Decimal
    Dim decStay As Decimal


    Function validateInputField() As Boolean
        If Not Decimal.TryParse(txtLength.Text, decLength) Then
            MessageBox.Show("Stay Length must be numeric")
        End If
        If Not Decimal.TryParse(txtMedication.Text, decMedication) Then
            MessageBox.Show("Medication cost must be numeric")
        End If
        If Not Decimal.TryParse(txtSurgical.Text, decSurgical) Then
            MessageBox.Show("Surgical cost must be numeric")
        End If
        If Not Decimal.TryParse(txtLabFees.Text, decLab) Then
            MessageBox.Show("Lab fees must be numeric")
        End If
        If Not Decimal.TryParse(txtPhysicalRehab.Text, decPhysical) Then
            MessageBox.Show("Physical Rehab cost must be numeric")
        End If

        Return True
    End Function

    Function CalcStayCharges(ByVal decLength As Decimal) As Decimal
        Dim decTotalStayPrice As Decimal
        decTotalStayPrice = decLength * decStay_Rate
        Return decTotalStayPrice
    End Function

    Function CalcMiscCharges(ByVal decmedication As Decimal, ByVal decsurgical As Decimal, ByVal decLab As Decimal, ByVal decPhysical As Decimal) As Decimal
        Dim decTotalMiscCharges As Decimal
        decTotalMiscCharges = decmedication + decsurgical + decLab + decPhysical
        Return decTotalMiscCharges
    End Function

    Private Function CalcTotalCharges(ByVal decTotalStayPrice As Decimal, ByVal decTotalMiscCharges As Decimal) As Decimal
        Dim decTotalCharge As Decimal
        decTotalCharge = decTotalStayPrice + decTotalMiscCharges
        Return decTotalCharge
    End Function
    Private Sub btnClear_Click(sender As Object, e As EventArgs) Handles btnClear.Click

        txtLabFees.Text = String.Empty
        txtLength.Text = String.Empty
        txtMedication.Text = String.Empty
        txtPhysicalRehab.Text = String.Empty
        txtSurgical.Text = String.Empty

    End Sub

    Private Sub btnExit_Click(sender As Object, e As EventArgs) Handles btnExit.Click
        Me.Close()
    End Sub

    Private Sub btnCalc_Click(sender As Object, e As EventArgs) Handles btnCalc.Click
        Dim decTotal As Decimal

        lblOutput.Text = String.Empty
        If validateInputField() Then
            decTotal = CalcTotalCharges(decTotalStayPrice, decTotalMiscCharges)

            lblOutput.Text = decTotal.ToString("c")
        End If
    End Sub

谢谢，

---

Eric

首先，您不需要

Decimal.TryParse（txtLength.Text，decLength）

来检查它是否是数字。您可以使用so

IsNumeric（txtLength.Text）

<如果成功，code>Decimal.TryParse将把

txtLength.Text

中的值分配给

decLength

，但在您的情况下不需要这样做

我会将方法

validateInputField

更改为：

Function validateInputField() As Boolean
    If Not IsNumeric(txtLength.Text) Then
        MessageBox.Show("Stay Length must be numeric")
        Return False
    End If
    If Not IsNumeric(txtMedication.Text) Then
        MessageBox.Show("Medication cost must be numeric")
        Return False
    End If
    If Not IsNumeric(txtSurgical.Text) Then
        MessageBox.Show("Surgical cost must be numeric")
        Return False
    End If
    If Not IsNumeric(txtLabFees.Text) Then
        MessageBox.Show("Lab fees must be numeric")
        Return False
    End If
    If Not IsNumeric(txtPhysicalRehab.Text) Then
        MessageBox.Show("Physical Rehab cost must be numeric")
        Return False
    End If

    Return True
End Function

我将删除所有这些，因为它们会给您带来困惑：

Private decLength As Integer
Private decMedication As Decimal
Private decSurgical As Decimal
Private decLab As Decimal
Private decPhysical As Decimal
Private decTotalStayPrice As Decimal
Private decTotalMiscCharges As Decimal

Private decTotal As Decimal
Dim decStay As Decimal

然后，您需要将正确的值传递给方法

CalcTotalCharges

：

decTotal = CalcTotalCharges(value1, value2)

以一种迂回的方式，您可能在追求：

Private Sub btnCalc_Click(sender As Object, e As EventArgs) Handles btnCalc.Click
    Dim decTotal As Decimal

    lblOutput.Text = ""
    If validateInputField() Then
        decTotal = CalcTotalCharges(CalcStayCharges(CDec(txtLength.Text)), CalcMiscCharges(CDec(txtMedication.Text), CDec(txtSurgical.Text), CDec(txtLabFees.Text), CDec(txtPhysicalRehab.Text)))

        lblOutput.Text = decTotal.ToString("c")
    End If
End Sub

---

首先，您不需要

Decimal.TryParse（txtLength.Text，decLength）

来检查它是否是数字。您可以使用so

IsNumeric（txtLength.Text）

<如果成功，code>Decimal.TryParse将把

txtLength.Text

中的值分配给

decLength

，但在您的情况下不需要这样做

我会将方法

validateInputField

更改为：

Function validateInputField() As Boolean
    If Not IsNumeric(txtLength.Text) Then
        MessageBox.Show("Stay Length must be numeric")
        Return False
    End If
    If Not IsNumeric(txtMedication.Text) Then
        MessageBox.Show("Medication cost must be numeric")
        Return False
    End If
    If Not IsNumeric(txtSurgical.Text) Then
        MessageBox.Show("Surgical cost must be numeric")
        Return False
    End If
    If Not IsNumeric(txtLabFees.Text) Then
        MessageBox.Show("Lab fees must be numeric")
        Return False
    End If
    If Not IsNumeric(txtPhysicalRehab.Text) Then
        MessageBox.Show("Physical Rehab cost must be numeric")
        Return False
    End If

    Return True
End Function

我将删除所有这些，因为它们会给您带来困惑：

Private decLength As Integer
Private decMedication As Decimal
Private decSurgical As Decimal
Private decLab As Decimal
Private decPhysical As Decimal
Private decTotalStayPrice As Decimal
Private decTotalMiscCharges As Decimal

Private decTotal As Decimal
Dim decStay As Decimal

然后，您需要将正确的值传递给方法

CalcTotalCharges

：

decTotal = CalcTotalCharges(value1, value2)

以一种迂回的方式，您可能在追求：

Private Sub btnCalc_Click(sender As Object, e As EventArgs) Handles btnCalc.Click
    Dim decTotal As Decimal

    lblOutput.Text = ""
    If validateInputField() Then
        decTotal = CalcTotalCharges(CalcStayCharges(CDec(txtLength.Text)), CalcMiscCharges(CDec(txtMedication.Text), CDec(txtSurgical.Text), CDec(txtLabFees.Text), CDec(txtPhysicalRehab.Text)))

        lblOutput.Text = decTotal.ToString("c")
    End If
End Sub

---

欢迎埃里克。正如您在vba标记描述中所看到的，vba和VB.NET是不等价的。谢谢，我纠正了这一点，在代码中添加了一个断点（单击左边空白处，得到一个红色点），然后逐步执行。您可以将鼠标指针悬停在变量上以获取其当前值。答案很好，我正在尝试。我只是想有一个方法来检查我的错误，以及在未来。为什么会被否决？好吧，我在顶部声明了变量=0，并认为我是从方法中的变量值中提取的，但实际上是从0值中提取的。我需要复习一下范围和变量声明。非常感谢您的帮助，并指出我的弱点所在。我将努力使我的变量声明不那么草率。保重，欢迎埃里克。正如您在vba标记描述中所看到的，vba和VB.NET是不等价的。谢谢，我纠正了这一点，在代码中添加了一个断点（单击左边空白处，得到一个红色点），然后逐步执行。您可以将鼠标指针悬停在变量上以获取其当前值。答案很好，我正在尝试。我只是想有一个方法来检查我的错误，以及在未来。为什么会被否决？好吧，我在顶部声明了变量=0，并认为我是从方法中的变量值中提取的，但实际上是从0值中提取的。我需要复习一下范围和变量声明。非常感谢您的帮助，并指出我的弱点所在。我将努力使我的变量声明不那么草率。小心点，Jinx修好了，谢谢。错误在于我忘记在布尔函数上返回false，而按钮上的代码没有问题。很高兴你把它整理好了。这就解决了它，谢谢。错误在于我忘记在布尔函数上返回false，而按钮上的代码没有问题。很高兴你把它整理好了。