如何打印 .rtf 文件？

Question

如何使用 C# 打印 .rtf 文件？ （WinForms/WPF 应用程序）

Answer 1

来自https://support.microsoft.com/en-us/kb/812425：

在 Visual C# .NET 或 Visual C# 2005 中，创建一个名为 RichTextBoxPrintCtrl 的新类库项目。默认情况下，创建 Class1.cs。 将 Class1.cs 的名称更改为 RichTextBoxPrintCtrl.cs。 在解决方案资源管理器中，右键单击引用，然后单击添加引用。 在“添加引用”对话框中，双击 System.Drawing.dll 和 System.Windows.Forms.dll，然后单击“确定”。

将 RichTextBoxPrintCtrl.cs 中的现有代码替换为以下代码：

using System;
using System.Windows.Forms;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Drawing.Printing;

namespace RichTextBoxPrintCtrl
{
    public class RichTextBoxPrintCtrl:RichTextBox
    {
        //Convert the unit used by the .NET framework (1/100 inch) 
        //and the unit used by Win32 API calls (twips 1/1440 inch)
        private const double anInch = 14.4;

        [StructLayout(LayoutKind.Sequential)] 
            private struct RECT
        {
            public int Left;
            public int Top;
            public int Right;
            public int Bottom;
        }

        [StructLayout(LayoutKind.Sequential)]
            private struct CHARRANGE
        {
            public int cpMin;         //First character of range (0 for start of doc)
            public int cpMax;           //Last character of range (-1 for end of doc)
        }

        [StructLayout(LayoutKind.Sequential)]
            private struct FORMATRANGE
        {
            public IntPtr hdc;             //Actual DC to draw on
            public IntPtr hdcTarget;       //Target DC for determining text formatting
            public RECT rc;                //Region of the DC to draw to (in twips)
            public RECT rcPage;            //Region of the whole DC (page size) (in twips)
            public CHARRANGE chrg;         //Range of text to draw (see earlier declaration)
        }

        private const int WM_USER  = 0x0400;
        private const int EM_FORMATRANGE  = WM_USER + 57;

        [DllImport("USER32.dll")]
        private static extern IntPtr SendMessage (IntPtr hWnd , int msg , IntPtr wp, IntPtr lp); 

        // Render the contents of the RichTextBox for printing
        //  Return the last character printed + 1 (printing start from this point for next page)
        public int Print( int charFrom, int charTo,PrintPageEventArgs e)
        {
            //Calculate the area to render and print
            RECT rectToPrint; 
            rectToPrint.Top = (int)(e.MarginBounds.Top * anInch);
            rectToPrint.Bottom = (int)(e.MarginBounds.Bottom * anInch);
            rectToPrint.Left = (int)(e.MarginBounds.Left * anInch);
            rectToPrint.Right = (int)(e.MarginBounds.Right * anInch);

            //Calculate the size of the page
            RECT rectPage; 
            rectPage.Top = (int)(e.PageBounds.Top * anInch);
            rectPage.Bottom = (int)(e.PageBounds.Bottom * anInch);
            rectPage.Left = (int)(e.PageBounds.Left * anInch);
            rectPage.Right = (int)(e.PageBounds.Right * anInch);

            IntPtr hdc = e.Graphics.GetHdc();

            FORMATRANGE fmtRange;
            fmtRange.chrg.cpMax = charTo;               //Indicate character from to character to 
            fmtRange.chrg.cpMin = charFrom;
            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 size of page

            IntPtr res = IntPtr.Zero;

            IntPtr wparam = IntPtr.Zero;
            wparam = new IntPtr(1);

            //Get the pointer to the FORMATRANGE structure in memory
            IntPtr lparam= 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();
        }

    }
}

在“调试”菜单上，单击“开始”以运行应用程序。显示表格 1。 在 RichTextBoxPrintCtrl 中键入一些文本。 单击页面设置以设置页面设​​置。 单击打印预览以查看页面的打印预览。 点击打印，打印 RichTextBoxPrintCtrl 的内容。

Answer 2

Printing Word(RTF) Documents in C#

或者，您可以在 RichTextBox 控件中打开文件，然后从那里send to printing。