问题 C＃打印（RichTextBox）

我试过了 如何打印RichTextBox控件的内容 它就像一个魅力。

你只需要创建一个自定义 RichTextBox 然后它将如此快速地打印整个文本，并保持在纸上的风格！

创建自定义的代码 RichTextBox

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();
        }

    }
}

主要来源包括 PrintDialog, PrintPreviewDialog, PrintDocument, and PageSetupDialog，但只有一个工作正常 PrintDocument 控制。所以我删除了一些额外的代码只是为了缩短有用的部分。但如果您对使用它们感兴趣，可以在链接页面中找到完整代码。

    private PrintDocument _printDocument = new PrintDocument();
    private int _checkPrint;
    public Form1()
    {
        InitializeComponent();
        _printDocument.BeginPrint += _printDocument_BeginPrint;
        _printDocument.PrintPage += _printDocument_PrintPage;
    }

    private void btnPrint_Click(object sender, EventArgs e)
    {
        PrintDialog printDialog=new PrintDialog();
        if (printDialog.ShowDialog() == DialogResult.OK)
            _printDocument.Print();
    }

    private void _printDocument_PrintPage(object sender, PrintPageEventArgs e)
    {
        // Print the content of RichTextBox. Store the last character printed.
        _checkPrint = rchEditor.Print(_checkPrint, rchEditor.TextLength, e);

        // Check for more pages
        e.HasMorePages = _checkPrint < rchEditor.TextLength;
    }

    private void _printDocument_BeginPrint(object sender, PrintEventArgs e)
    {
        _checkPrint = 0;
    }

看来你的代码有问题，它只重新打印第一页因为

StringReader reader = new StringReader(eintragRichTextBox.Text);

在你的 DocumentToPrint_PrintPage() 

用那个！

StringReader reader;
        int prov = 0;

        private void DocumentToPrint_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)
        {


            if (prov == 0)
            {
                prov = 1;
                reader = new StringReader(eintragRichTextBox.Text);
            }
float LinesPerPage = 0;
            float YPosition = 0;
            int Count = 0;
            float LeftMargin = e.MarginBounds.Left;
            float TopMargin = e.MarginBounds.Top;
            string Line = null;

....