【发布时间】：2013-10-07 18:06:57
【问题描述】：
我遇到的问题是，在打印多页文档时，除最后一页外，每一页都会覆盖另一页。就好像在开始新页面之前没有清除页面内容一样。
我已将它减少到最少的代码量，但我仍然无法让它正常运行。
PrintPage 代码如下所示：
Private Sub printDoc_printExceptionPage(sender As Object, e As System.Drawing.Printing.PrintPageEventArgs) Handles printDoc.PrintPage
Dim printFont As New Font("Courier New", 9, FontStyle.Regular)
Dim lineHeight As Single = 0
Dim xpos As Single = e.MarginBounds.Left
Dim ypos As Single = e.MarginBounds.Top
If lineIndex = docRec.Count Then
e.HasMorePages = False
Exit Sub
End If
printFont = New Font("Courier New", 9, FontStyle.Regular)
lineHeight = printFont.GetHeight(e.Graphics)
While lineIndex < docRec.Count
e.Graphics.DrawString(docRec.Item(lineIndex), printFont, Brushes.Black, xpos, ypos, New StringFormat())
ypos += lineHeight
lineIndex += 1
If lineIndex Mod 35 = 0 Then
pageCount += 1
e.HasMorePages = True
Exit Sub
End If
End While
End Sub
docRec 是一个简单的字符串列表，其中包含输出的行 - 它被声明为“dim docRec as new List(of String)”并在之前填充。
在这一点上我完全猜不透，显然我的 Google Fu 让我失望了，因为我在任何地方都找不到这个问题的另一个实例。
如果启动打印的代码是相关的，那么这就是它的全部荣耀：
PrintDlg.AllowPrintToFile = False
PrintDlg.PrinterSettings = New PrinterSettings
Dim test As New PrintPreviewDialog
printDoc = New PrintDocument
printDoc.PrinterSettings.DefaultPageSettings.Landscape = True
If PrintDlg.ShowDialog = Windows.Forms.DialogResult.OK Then
AddHandler printDoc.PrintPage, AddressOf printDoc_printExceptionPage
printDoc.DefaultPageSettings.Landscape = True
BuildDoc()
lineIndex = 1
pageCount = 1
'printDoc.Print()
test.Document = printDoc
test.ShowDialog()
End If
感谢您的帮助！
g.
[编辑] 我修改了以下代码以添加调试信息流，以查看事情是如何执行的。
While lineIndex < docRec.Count
Debug.Print("ypos (" + CStr(ypos) + ") line:" + CStr(lineIndex))
e.Graphics.DrawString(docRec.Item(lineIndex), printFont, Brushes.Black, xpos, ypos, New StringFormat())
ypos += printFont.GetHeight(e.Graphics)
lineIndex += 1
If lineIndex Mod 35 = 0 Then 'If lineTop + lineHeight > e.MarginBounds.Bottom Then
Debug.Print("done with page " + CStr(pageCount))
pageCount += 1
e.HasMorePages = True
Exit Sub
End If
End While
输出如下：
ypos (0) line:1
ypos (14.16015) line:2
ypos (28.32031) line:3
ypos (42.48046) line:4
ypos (56.64062) line:5
ypos (70.80077) line:6
ypos (84.96093) line:7
ypos (99.12109) line:8
ypos (113.2812) line:9
ypos (127.4414) line:10
ypos (141.6015) line:11
ypos (155.7617) line:12
ypos (169.9219) line:13
ypos (184.082) line:14
ypos (198.2422) line:15
ypos (212.4023) line:16
ypos (226.5625) line:17
ypos (240.7226) line:18
ypos (254.8828) line:19
ypos (269.0429) line:20
ypos (283.2031) line:21
ypos (297.3633) line:22
ypos (311.5234) line:23
ypos (325.6836) line:24
ypos (339.8437) line:25
ypos (354.0039) line:26
ypos (368.164) line:27
ypos (382.3242) line:28
ypos (396.4843) line:29
ypos (410.6445) line:30
ypos (424.8047) line:31
ypos (438.9648) line:32
ypos (453.125) line:33
ypos (467.2851) line:34
done with page 1
ypos (0) line:35
ypos (14.16015) line:36
ypos (28.32031) line:37
ypos (42.48046) line:38
ypos (56.64062) line:39
ypos (70.80077) line:40
ypos (84.96093) line:41
ypos (99.12109) line:42
ypos (113.2812) line:43
ypos (127.4414) line:44
ypos (141.6015) line:45
ypos (155.7617) line:46
ypos (169.9219) line:47
ypos (184.082) line:48
ypos (198.2422) line:49
ypos (212.4023) line:50
ypos (226.5625) line:51
ypos (240.7226) line:52
ypos (254.8828) line:53
ypos (269.0429) line:54
ypos (283.2031) line:55
ypos (297.3633) line:56
ypos (311.5234) line:57
ypos (325.6836) line:58
ypos (339.8437) line:59
ypos (354.0039) line:60
ypos (368.164) line:61
ypos (382.3242) line:62
此示例中的行数较少，它会生成两个页面，第二个页面会覆盖第一个页面的内容。
【问题讨论】：
-
我看不出问题所在，可能是你搞砸了太多。当 PrintPage 事件处理程序对每个页面运行不止一次时，就会发生这种情况。当您过于频繁地调用 AddHandler 时会发生这种情况。
-
每次执行时我只调用一次 AddHandler。如果第一次打印有效而第二次无效，我可以理解可能存在的问题，但这里不是这种情况。
标签： vb.net printdocument