禁用在RichTextBox中滾動（C＃）

Question

我編寫了代碼，以在單獨的頁面（如Microsoft Word）中顯示文本，我使用了一個文本框集合，當用戶填充一個文本框時，會自動顯示新的文本框，並且光標移至該文本框。

問題是，當用戶在文本框中寫出最后一行時，該框會向下滾動一點，正如您將在何時運行此代碼時所看到的那樣，因此如何禁用滾動。

編碼 ：

        using System;
        using System.Collections.Generic;
        using System.ComponentModel;
        using System.Data;
        using System.Drawing;
        using System.Linq;
        using System.Text;
        using System.Windows.Forms;
        using System.Runtime.InteropServices;

        namespace WindowsFormsApplication1
        {
            public partial class Form1 : Form
            {
                List<myRTB> pages; // collection of our RichTextBox, use as pages

                public Form1()
                {
                    InitializeComponent();

                    pages = new List<myRTB>();
                    pages.Add(new myRTB());
                    pages[0].Width = 200;
                    pages[0].Height = 290;
                    pages[0].Location = new Point(50, 10);
                    pages[0].Name = "0";
                    this.Controls.Add(pages[0]);

                    this.Width = 300;
                    this.Height = 360;
                    this.AutoScroll = true;
                }

                public void AddPage(int correntPageIndex)
                {
                    if (correntPageIndex == (pages.Count - 1)) 
                    {
                        // create a new page
                        pages.Add(new myRTB());
                        pages[correntPageIndex + 1].Width = 200;
                        pages[correntPageIndex + 1].Height = 290;
                        pages[correntPageIndex + 1].Location = new Point(50, pages[correntPageIndex].Location.Y + 300);
                        this.Controls.Add(pages[pages.Count - 1]);
                        this.Name = (correntPageIndex + 1).ToString();
                    }

                    bool CursorInEnd = (pages[correntPageIndex].SelectionStart == pages[correntPageIndex].TextLength);

                    // Transfer the last word on the previous page, to the new page

                    int lastLineIndex = pages[correntPageIndex].GetLineFromCharIndex(pages[correntPageIndex].TextLength - 2);
                    // find the index of the first char in the last line
                    int indexOfFirstCharInLastLine = pages[correntPageIndex].GetFirstCharIndexFromLine(lastLineIndex);
                    // find the index of the last space in the last line
                    int indexOfLastSpace = pages[correntPageIndex].Text.LastIndexOf(' ', indexOfFirstCharInLastLine);

                    string restOfString; 

                    if (indexOfLastSpace < 0) // no spaces in the last line
                    {
                        restOfString = pages[correntPageIndex].Text.Substring(pages[correntPageIndex].TextLength - 1);
                        pages[correntPageIndex + 1].Text.Insert(0, restOfString);
                        pages[correntPageIndex].Text.Remove(pages[correntPageIndex].TextLength - 1);
                    }
                    else // there is spaces in the last line
                    {
                        restOfString = pages[correntPageIndex].Text.Substring(indexOfLastSpace + 1);
                        pages[correntPageIndex + 1].Text = pages[correntPageIndex + 1].Text.Insert(0, restOfString);
                        pages[correntPageIndex].Text = pages[correntPageIndex].Text.Remove(indexOfLastSpace + 1);
                    }

                    if (CursorInEnd)
                    {
                        // Move the cursor to next page 
                        pages[correntPageIndex + 1].SelectionStart = restOfString.Length;
                        pages[correntPageIndex + 1].Focus();
                    }
                }
            }

            class myRTB : RichTextBox
            {
                public myRTB()
                {
                    this.ScrollBars = RichTextBoxScrollBars.None;
                }
                protected override void WndProc(ref Message m)
                {
                    // catch the request resize message
                    if (m.Msg == (WM_REFLECT | WM_NOTIFY)) 
                    {
                        REQRESIZE rrs = (REQRESIZE)(Marshal.PtrToStructure(m.LParam, typeof(REQRESIZE)));
                        if (rrs.nmhdr.code == EN_REQUESTRESIZE)
                        {
                            if (rrs.rc.ToRectangle().Height > this.ClientRectangle.Height)
                            {
                                ((Form1)Parent).AddPage(int.Parse(this.Name));
                            }
                        }
                    }
                    base.WndProc(ref m);
                }

                [StructLayout(LayoutKind.Sequential)]
                public struct NMHDR
                {
                    public IntPtr HWND;
                    public uint idFrom;
                    public int code;
                    public override String ToString()
                    {
                        return String.Format("Hwnd: {0}, ControlID: {1}, Code: {2}",
                        HWND, idFrom, code);
                    }
                }

                [StructLayout(LayoutKind.Sequential)]
                public struct REQRESIZE
                {
                    public NMHDR nmhdr;
                    public RECT rc;
                }

                [StructLayout(LayoutKind.Sequential)]
                public struct RECT
                {
                    public int Left, Top, Right, Bottom;
                    public override string ToString()
                    {
                        return String.Format("{0}, {1}, {2}, {3}", Left, Top, Right,
                        Bottom);
                    }
                    public Rectangle ToRectangle()
                    {
                        return Rectangle.FromLTRB(Left, Top, Right, Bottom);
                    }
                }

                public const int WM_USER = 0x400;
                public const int WM_NOTIFY = 0x4E;
                public const int WM_REFLECT = WM_USER + 0x1C00;
                public const int EN_REQUESTRESIZE = 0x701;

            }
        }

Answer 1

為確保文本不會自動滾動，請查看以下針對類似問題的答案。

禁用RichTextBox自動滾動

這是您的問題的另一個好答案：

防止在RichTextBox中自動滾動

我復制了上面鏈接中的代碼，請確保為用戶提供此代碼的功勞（不是我的）

   [System.Runtime.InteropServices.DllImport("user32.dll")] 

   static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, Int32 wParam, Int32 lParam); 
   const int WM_USER = 0x400; 
   const int EM_HIDESELECTION = WM_USER + 63;

   void OnAppend(string text)     
   {         
   bool focused = richTextBox1.Focused; 
   //backup initial selection 
   int selection = richTextBox1.SelectionStart;         
   int length = richTextBox1.SelectionLength;         
   //allow autoscroll if selection is at end of text         
      bool autoscroll = (selection==richTextBox1.Text.Length);
      if (!autoscroll)         
      {  
         //shift focus from RichTextBox to some other control            
        if (focused) 
          textBox1.Focus();             
         //hide selection             
      SendMessage(richTextBox1.Handle, EM_HIDESELECTION, 1, 0);
      }          

      richTextBox1.AppendText(text);

      if (!autoscroll)         
      {             
         //restore initial selection            
         richTextBox1.SelectionStart = selection;             
         richTextBox1.SelectionLength = length;             
         //unhide selection             
         SendMessage(richTextBox1.Handle, EM_HIDESELECTION, 0, 0);             
         //restore focus to RichTextBox             
         if(focused) richTextBox1.Focus();         
      }     
   }