如何将一列的所有值相乘? [英] How to multiply all the values of a column?

问题描述

我有一个像这样的DataGridView布局:

I've a DataGridView like this layout:

我想找到一种方法来乘以"Quota"列的所有值，特别是，我编写了这样的代码:

I would like to find a way to multiply all values of the column "Quota", in particular, I wrote a code like this:

    If MetroGrid1.Rows.Count > 0 Then
        If MetroGrid1.Columns.Contains("Quota") Then
            Dim CostTotal As Decimal = MetroGrid1.Rows.Cast(Of DataGridViewRow) _
                                       .Select(
                                        Function(x)
                                            Return CDec(x.Cells("Quota").Value)
                                        End Function
            ).Sum
            Dim risultato = CostTotal * giocata

问题在于，唯一可用的模式是总和和平均值，但没有乘法.我想找到一种用某些命令替换 .Sum 的方法，该命令可以在必要时让我乘以或完全改变算法.

The problem is that the only mode available is the sum and average, but there is no multiplication. I would like to find a way to replace .Sum with some command that allows me to multiply or totally change the algorithm if necessary.

推荐答案

要在遍历网格时乘以每个单元格，可以通过将值相乘并将其添加到变量中来循环...首先，我们要确保存在是一个值，如果是这样，请尝试将该值转换为双精度值.如果是这样，则将旧值乘以新值，依此类推...

To multiply every cell as you go through the grid you can loop through multiplying the values and adding it to a variable... First we'll make sure there is a value and if so lets try and cast that value as a double. If so multiply the old values with the new one and so on...

 Dim dblTotal As Double = 0
 Dim dblValue As Double = 0


 For i As Integer = 0 To MetroGrid1.Rows.Count - 1
    If MetroGrid1.Rows(i).Cells("Quota").Value IsNot DBNull.Value Then
     If Double.TryParse(MetroGrid1.Rows(i).Cells("Quota").Value.ToString, dblValue) Then
      dblTotal *= dblValue
     End If
    End If

 Next

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