执行简单的算术运算并使用Label显示答案

Question

我们说我在文本框和标签中有以下内容：

 txtAmount1_1
 txtAmount1_2
 txtAmount1_3

 txtAmount2_1
 txtAmount2_2
 txtAmount2_3

 lblTotal1
 lblTotal2

 lblGrandTotal

我想将txtAmount1_1，txtAmount1_2和txtAmount1_3的总和显示为lblTotal1，将txtAmount2_1，txtAmount2_2和txtAmount2_3的总和显示为lblTotal2，将lblTotal1和lblTotal2的总和显示为lblGrandTotal。所以我输入了以下代码：

  Private Sub txtAmount1_1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtAmount1_1.TextChanged
    Dim a As Decimal

    a = Val(txtAmount1_1.Text) + Val(txtAmount1_2.Text) + Val(txtAmount1_3.Text)
    lblTotal1.Text = Val(a)
End Sub

 Private Sub txtAmount1_2_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtAmount1_2.TextChanged
    Dim a As Decimal

    a = Val(txtAmount1_1.Text) + Val(txtAmount1_2.Text) + Val(txtAmount1_3.Text)
    lblTotal1.Text = Val(a)
End Sub

 Private Sub txtAmount1_3_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtAmount1_3.TextChanged
    Dim a As Decimal

    a = Val(txtAmount1_1.Text) + Val(txtAmount1_2.Text) + Val(txtAmount1_3.Text)
    lblTotal1.Text = Val(a)
End Sub

 Private Sub txtAmount2_1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtAmount2_1.TextChanged
    Dim a As Decimal

    a = Val(txtAmount2_1.Text) + Val(txtAmount2_2.Text) + Val(txtAmount2_3.Text)
    lblTotal1.Text = Val(a)
End Sub

 Private Sub txtAmount2_2_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtAmount2_2.TextChanged
    Dim a As Decimal

    a = Val(txtAmount2_1.Text) + Val(txtAmount2_2.Text) + Val(txtAmount2_3.Text)
    lblTotal1.Text = Val(a)
End Sub

 Private Sub txtAmount2_3_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtAmount2_3.TextChanged
    Dim a As Decimal

    a = Val(txtAmount2_1.Text) + Val(txtAmount2_2.Text) + Val(txtAmount2_3.Text)
    lblTotal1.Text = Val(a)
End Sub

 Private Sub lblTotal1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles lblTotal1.Click
    Dim a As Decimal
    Dim b As Decimal

    a = Val(txtAmount1_1.Text) + Val(txtAmount1_2.Text) + Val(txtAmount1_3.Text)
    lblTotal1.Text = Val(a)

    b = Val(lblTotal1.Text) + Val(lblTotal2.Text)
    lblGrandTotal.Text = Val(b)
End Sub

 Private Sub lblTotal2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles lblTotal2.Click
    Dim a As Decimal
    Dim b As Decimal

    a = Val(txtAmount2_1.Text) + Val(txtAmount2_2.Text) + Val(txtAmount2_3.Text)
    lblTotal1.Text = Val(a)

    b = Val(lblTotal1.Text) + Val(lblTotal2.Text)
    lblGrandTotal.Text = Val(b)
End Sub

Private Sub lblGrandTotal_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles lblGrandTotal.Click
    Dim a As Decimal

    a = Val(lblTotal1.Text) + Val(lblTotal2.Text)
    lblGrandTotal.Text = Val(a)
End Sub

lblTotal1和lblTotal2工作正常（我的意思是它正确显示文本框中值的总和），但lblGrandTotal不起作用（不显示lblTotal1和lblTotal2的总和）。为什么会这样？我的代码有问题吗？然后在哪里？

Answer 1

我认为你的程序有点凌乱，我没有看到你想要的概念，但我试着修改你的一些程序，或者我认为这就是你想要的......

Private Sub txtAmount1_1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtAmount1_1.TextChanged
    Dim a As Decimal

    a = Val(txtAmount1_1.Text) + Val(txtAmount1_2.Text) + Val(txtAmount1_3.Text)
    lblTotal1.Text = Val(a)
End Sub

Private Sub txtAmount1_2_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtAmount1_2.TextChanged
    Dim a As Decimal

    a = Val(txtAmount1_1.Text) + Val(txtAmount1_2.Text) + Val(txtAmount1_3.Text)
    lblTotal1.Text = Val(a)
End Sub

Private Sub txtAmount1_3_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtAmount1_3.TextChanged
    Dim a As Decimal

    a = Val(txtAmount1_1.Text) + Val(txtAmount1_2.Text) + Val(txtAmount1_3.Text)
    lblTotal1.Text = Val(a)
End Sub

Private Sub txtAmount2_1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtAmount2_1.TextChanged
    Dim a As Decimal

    a = Val(txtAmount2_1.Text) + Val(txtAmount2_2.Text) + Val(txtAmount2_3.Text)
    lblTotal2.Text = Val(a)
End Sub

Private Sub txtAmount2_2_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtAmount2_2.TextChanged
    Dim a As Decimal

    a = Val(txtAmount2_1.Text) + Val(txtAmount2_2.Text) + Val(txtAmount2_3.Text)
    lblTotal2.Text = Val(a)
End Sub

Private Sub txtAmount2_3_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtAmount2_3.TextChanged
    Dim a As Decimal

    a = Val(txtAmount2_1.Text) + Val(txtAmount2_2.Text) + Val(txtAmount2_3.Text)
    lblTotal2.Text = Val(a)
End Sub

Private Sub lblTotal1_TextChange(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles lblTotal1.TextChanged
    Dim a As Decimal
    Dim b As Decimal

    a = Val(txtAmount1_1.Text) + Val(txtAmount1_2.Text) + Val(txtAmount1_3.Text)
    lblTotal1.Text = Val(a)

    b = Val(lblTotal1.Text) + Val(lblTotal2.Text)
    lblGrandTotal.Text = Val(b)
End Sub

Private Sub lblTotal2_TextChange(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles lblTotal2.TextChanged
    Dim a As Decimal
    Dim b As Decimal

    a = Val(txtAmount2_1.Text) + Val(txtAmount2_2.Text) + Val(txtAmount2_3.Text)
    lblTotal1.Text = Val(a)

    b = Val(lblTotal1.Text) + Val(lblTotal2.Text)
    lblGrandTotal.Text = Val(b)
End Sub

我注意到lblTotal2是常量或不变化。我认为这是lblTotal1的相同概念所以我更改它以添加txtAmount2_1，txtAmount2_2，txtAmount2_3然后我将标签上的click事件更改为Text change，因为事件只会在您单击标签时触发，我知道您想要是自动显示所有文本框的总和，并显示两个lblTotal1和lblTotal2的最终总数......

Answer 2

我已经发现了我的错误。这是一个印刷错误（而不是Val(txtAmount1_1.Text)，我只是键入Val(txtAmount1_1)）。它现在工作正常。我确实使用过Val，因为没有使用它会让我的代码出错。