nge As CHARRANGE
cRange.cpMin = charFrom
cRange.cpMax = charTo
' Calculate the area to render and print
Dim rectToPrint As RECT
rectToPrint.Top = e.MarginBounds.Top * AnInch
rectToPrint.Bottom = e.MarginBounds.Bottom * AnInch
rectToPrint.Left = e.MarginBounds.Left * AnInch
rectToPrint.Right = e.MarginBounds.Right * AnInch
' Calculate the size of the page
Dim rectPage As RECT
rectPage.Top = e.PageBounds.Top * AnInch
rectPage.Bottom = e.PageBounds.Bottom * AnInch
rectPage.Left = e.PageBounds.Left * AnInch
rectPage.Right = e.PageBounds.Right * AnInch
Dim hdc As IntPtr = e.Graphics.GetHdc()
Dim fmtRange As FORMATRANGE
fmtRange.chrg = cRange ' Indicate character from to character to
fmtRange.hdc = hdc ' Use the same DC for measuring and rendering
fmtRange.hdcTarget = hdc ' Point at printer hDC
fmtRange.rc = rectToPrint ' Indicate the area on page to print
fmtRange.rcPage = rectPage ' Indicate whole size of page
Dim res As IntPtr = IntPtr.Zero
Dim wparam As IntPtr = IntPtr.Zero
wparam = New IntPtr(1)
' Move the pointer to the FORMATRANGE structure in memory
Dim lparam As IntPtr = IntPtr.Zero
lparam = Marshal.AllocCoTaskMem(Marshal.SizeOf(fmtRange))
Marshal.StructureToPtr(fmtRange, lparam, False)
' Send the rendered data for printing
res = SendMessage(Handle, EM_FORMATRANGE, wparam, lparam)
' Free the block of memory allocated
Marshal.FreeCoTaskMem(lparam)
' Release the device context handle obtained by a previous call
e.Graphics.ReleaseHdc(hdc)
' Return last + 1 character printer
Return res.ToInt32()
End Function
End Class
End Namespace
8. 要创建“RichTextBoxPrintCtrl.dll”,请在“生成”菜单上单击“生成解决方案”。
测试控件
要测试该控件,请按照下列步骤操作: 1. 使用 Visual Basic .NET 新建一个 Windows 应用程序项目。
默认情况下,将创建 Form1.vb。
2. 从工具箱中,将一个按钮拖到 Form1 上。将名称更改为 btnPageSetup,然后将“文本”更改为页面设置。
3. 从工具箱中,将另一个按钮拖到 Form1 上。将名称更改为 btnPrintPreview,然后将“文本”更改为打印预览。
4. 从工具箱中,将另一个按钮拖到 Form1 上。将名称更改为 btnPrint,然后将“文本”更改为打印。
5. 在工具箱中,依次双击“PrintDialog”、“PrintPreviewDialog”和“PrintDocument”,然后双击“PageSetupDialog”将这些控件添加到 Form1 中。
6. 将“PrintDialog1”、“PrintPreviewDialog1”和“PageSetupDialog1”的 Document 属性修改为PrintDocument1。
7. 在“工具”菜单上,单击“自定义工具箱”。
8. 单击“.NET Framework 组件”,单击“浏览”,单击以选择“RichTextBoxPrintCtrl.dll”,然后单击“确定”。
9. 从工具箱中,将“RichTextBoxPrintCtrl”拖到 Form1 上。
10. 在解决方案资源管理器中,右键单击“Form1.vb”,然后单击“查看代码”。
11. 将以下代码添加到 Form1 类中:
Private checkPrint As Integer
Private Sub PrintDocument1_B
cRange.cpMin = charFrom
cRange.cpMax = charTo
' Calculate the area to render and print
Dim rectToPrint As RECT
rectToPrint.Top = e.MarginBounds.Top * AnInch
rectToPrint.Bottom = e.MarginBounds.Bottom * AnInch
rectToPrint.Left = e.MarginBounds.Left * AnInch
rectToPrint.Right = e.MarginBounds.Right * AnInch
' Calculate the size of the page
Dim rectPage As RECT
rectPage.Top = e.PageBounds.Top * AnInch
rectPage.Bottom = e.PageBounds.Bottom * AnInch
rectPage.Left = e.PageBounds.Left * AnInch
rectPage.Right = e.PageBounds.Right * AnInch
Dim hdc As IntPtr = e.Graphics.GetHdc()
Dim fmtRange As FORMATRANGE
fmtRange.chrg = cRange ' Indicate character from to character to
fmtRange.hdc = hdc ' Use the same DC for measuring and rendering
fmtRange.hdcTarget = hdc ' Point at printer hDC
fmtRange.rc = rectToPrint ' Indicate the area on page to print
fmtRange.rcPage = rectPage ' Indicate whole size of page
Dim res As IntPtr = IntPtr.Zero
Dim wparam As IntPtr = IntPtr.Zero
wparam = New IntPtr(1)
' Move the pointer to the FORMATRANGE structure in memory
Dim lparam As IntPtr = IntPtr.Zero
lparam = Marshal.AllocCoTaskMem(Marshal.SizeOf(fmtRange))
Marshal.StructureToPtr(fmtRange, lparam, False)
' Send the rendered data for printing
res = SendMessage(Handle, EM_FORMATRANGE, wparam, lparam)
' Free the block of memory allocated
Marshal.FreeCoTaskMem(lparam)
' Release the device context handle obtained by a previous call
e.Graphics.ReleaseHdc(hdc)
' Return last + 1 character printer
Return res.ToInt32()
End Function
End Class
End Namespace
8. 要创建“RichTextBoxPrintCtrl.dll”,请在“生成”菜单上单击“生成解决方案”。
测试控件
要测试该控件,请按照下列步骤操作: 1. 使用 Visual Basic .NET 新建一个 Windows 应用程序项目。
默认情况下,将创建 Form1.vb。
2. 从工具箱中,将一个按钮拖到 Form1 上。将名称更改为 btnPageSetup,然后将“文本”更改为页面设置。
3. 从工具箱中,将另一个按钮拖到 Form1 上。将名称更改为 btnPrintPreview,然后将“文本”更改为打印预览。
4. 从工具箱中,将另一个按钮拖到 Form1 上。将名称更改为 btnPrint,然后将“文本”更改为打印。
5. 在工具箱中,依次双击“PrintDialog”、“PrintPreviewDialog”和“PrintDocument”,然后双击“PageSetupDialog”将这些控件添加到 Form1 中。
6. 将“PrintDialog1”、“PrintPreviewDialog1”和“PageSetupDialog1”的 Document 属性修改为PrintDocument1。
7. 在“工具”菜单上,单击“自定义工具箱”。
8. 单击“.NET Framework 组件”,单击“浏览”,单击以选择“RichTextBoxPrintCtrl.dll”,然后单击“确定”。
9. 从工具箱中,将“RichTextBoxPrintCtrl”拖到 Form1 上。
10. 在解决方案资源管理器中,右键单击“Form1.vb”,然后单击“查看代码”。
11. 将以下代码添加到 Form1 类中:
Private checkPrint As Integer
Private Sub PrintDocument1_B
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