以彩色din DataGridView VB.Net打印交替的行

Question

我用数据填充了DatagridView，然后我想用交替的颜色打印该数据，但是当我执行PrintPreview时，我只看到我的列显示交替的颜色。

这是我正在尝试的；

Private Sub PrintDocument1_PrintPage(sender As System.Object, e As System.Drawing.Printing.PrintPageEventArgs) Handles PrintDocument1.PrintPage
    With DataGridView1
        Dim fmt As StringFormat = New StringFormat(StringFormatFlags.LineLimit)
        fmt.LineAlignment = StringAlignment.Center
        fmt.Trimming = StringTrimming.EllipsisCharacter
        Dim y As Single = e.MarginBounds.Top - 50
        Dim myBrush As Brush
        Dim myBrush1 As Brush
        Dim rowID As Integer = 0

        myBrush = New SolidBrush(Color.AliceBlue)
        myBrush1 = New SolidBrush(Color.White)
        Do While mRow < .RowCount
            Dim row As DataGridViewRow = .Rows(mRow)
            Dim x As Single = e.MarginBounds.Left - 65
            Dim h As Single = 0
            For Each cell As DataGridViewCell In row.Cells
                Dim rc As RectangleF = New RectangleF(x, y, cell.Size.Width, cell.Size.Height)

                e.Graphics.DrawRectangle(Pens.Black, rc.Left, rc.Top, rc.Width, rc.Height)
                If (newpage) Then
                    'e.Graphics.FillRectangle(myBrush, rc)
                    e.Graphics.DrawString(DataGridView1.Columns(cell.ColumnIndex).HeaderText, .Font, Brushes.Black, rc, fmt)
                Else
                    If rowID = 0 Then
                        e.Graphics.FillRectangle(myBrush, rc)
                        rowID = 1
                    ElseIf rowID = 1 Then
                        e.Graphics.FillRectangle(myBrush1, rc)
                        rowID = 0
                    End If
                    e.Graphics.DrawString(DataGridView1.Rows(cell.RowIndex).Cells(cell.ColumnIndex).FormattedValue.ToString(), .Font, Brushes.Black, rc, fmt)
                End If
                x += rc.Width
                h = Math.Max(h, rc.Height)

            Next
            newpage = False
            y += h
            mRow += 1

            If y + h > e.MarginBounds.Bottom Then
                e.HasMorePages = True
                mRow -= 1
                newpage = True
                Exit Sub
            End If
        Loop
        mRow = 0
    End With
End Sub

我试图将

If rowID = 0 Then
                        e.Graphics.FillRectangle(myBrush, rc)
                        rowID = 1
                    ElseIf rowID = 1 Then
                        e.Graphics.FillRectangle(myBrush1, rc)
                        rowID = 0
                    End If

在其他地方，但我得到相同的结果。 这种用法在ASP.Net中很容易，但是现在我在VB.Net中工作。 有任何想法吗？

Answer 1

问题在于您的笔刷选择位于单元格的For Each循环内。 如果您不想更改每个单元格上的笔刷，则不要选择每个单元格上的笔刷。 将选择画笔的代码放在外循环内，但在内循环外。

您应该这样做：

Dim useAlternateBrush = False

Using standardBrush As New SolidBrush(Color.AliceBlue),
      alternateBrush As New SolidBrush(Color.White)
    Do While mRow < .RowCount
        '...

        Dim brush = If(useAlternateBrush, alternateBrush, standardBrush)

        useAlternateBrush = Not useAlternateBrush

        '...

        For Each cell As DataGridViewCell In row.Cells
            '...

            'Use brush here.

            '...
        Next
    Loop
End Using

请注意， SolidBrush对象是Using语句创建的，因此将它们隐式放置在End Using语句中。 如果可能的话，应始终丢弃一次性物品，这几乎总是如此，并且应创建短暂的一次性物品并Using块进行处置。