excel vba选择右下三角形

Question

我有一个关于选择三角形的问题 我知道我可以通过这段代码选择对角线：

Sub SelectDiagonal()
a = Selection.Row()
b = Selection.Column()
c = Selection.Rows.Count
d = Selection.Columns.Count
Dim Rng As Range
Set Rng = Cells(a + c - 1, b)
 For i = 1 To c - 1
  Set Rng = Union(Rng, Cells(a + c - 1 - i, b + i))
   Next
Rng.Select
End Sub

但是，我想选择所有向下三角形 我想要的是选择黄色单元格，如下图。

我试过这段代码：

Sub SelectDownTriangle()
a = Selection.Row()
b = Selection.Column()
c = Selection.Rows.Count
d = Selection.Columns.Count

  For i = 1 To c - 1
     For j = 1 To i
     Cells(a + i, b + d - j).Select
     Next
  Next
End Sub

但它不起作用。

有任何帮助吗？谢谢

[编辑]
在@ Vityata的回答中，我编辑了代码：

Sub SelectDownTriangle()
    Dim a As Long, b As Long, c As Long, d As Long
    Dim i As Long

    a = Selection.Row()
    b = Selection.Column()
    c = Selection.Rows.Count
    d = Selection.Columns.Count

    Dim lastCol As Long
    Dim Rng     As Range

    Set Rng = Cells(a + c - 1, b + 1)

    For i = 1 To c - 1
        Set Rng = Union(Rng, Cells(a + c - 2 - i, b + i + 1))
        If Cells(a + c - 2 - i, b + i + 1).Column > lastCol Then
            lastCol = Cells(a + c - 2 - i, b + i).Column
        End If
    Next

    Dim colCounter      As Long
    Dim myCell          As Range

    For Each myCell In Rng
        For colCounter = myCell.Column To lastCol
            Cells(myCell.Row, colCounter).Interior.Color = vbGreen
        Next colCounter
    Next myCell

End Sub

但是，输出不正确

我想要的是：

Answer 1

使用你的代码，你需要一个循环，它可以循环rng到最后一列的每个单元格，并用颜色填充它：

Option Explicit

Sub SelectDiagonal()
    Dim a As Long, b As Long, c As Long, d As Long
    Dim i As Long

    a = Selection.row()
    b = Selection.Column()
    c = Selection.Rows.Count
    d = Selection.Columns.Count

    Dim lastCol As Long
    Dim Rng     As Range

    Set Rng = Cells(a + c - 1, b)

    For i = 1 To c - 1
        Set Rng = Union(Rng, Cells(a + c - 1 - i, b + i))
        If Cells(a + c - 1 - i, b + i).Column > lastCol Then
            lastCol = Cells(a + c - 1 - i, b + i).Column
        End If
    Next

    Dim colCounter      As Long
    Dim myCell          As Range

    For Each myCell In Rng
        For colCounter = myCell.Column To lastCol
            Cells(myCell.row, colCounter).Interior.Color = vbGreen
        Next colCounter
    Next myCell

End Sub