c# - RichTextBox 在面板滚动时自动垂直滚动 c#

Question

我在 WinForm 的面板内有一个 RichTextBox。我想隐藏RichTextBox的垂直滚动条，使其滚动与容器面板的垂直滚动条同步；每当 textbox 中的文本溢出时，面板的滚动条就会出现，每当我滚动面板的滚动条时，textbox 就会滚动。如何实现？

Answer 1

正如我在评论中所说，我们必须处理 win32 消息并使用一些 hack。我已经使用了我所有关于 win32 消息和控制 hack/自定义的知识，为您制作了这个演示。它并不完整，当然也不会像 RichTextBox 的标准滚动条那样完美。缺点是如果你一直按住箭头键，滚动条拇指不会向右移动，但是如果你正常按下箭头键，滚动条拇指会像标准滚动条一样将插入符号移动到 View 中。您可以自己尝试代码以查看它的实际效果:

public class Form1 : Form {
   [DllImport("user32")]
   private static extern int SendMessage(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam);
   public Form1(){
      InitializeComponent();
      //initialize some properties for your richTextBox1 (this should be added as a child of your panel1)
      richTextBox1.ScrollBars = RichTextBoxScrollBars.Horizontal;
      richTextBox1.BorderStyle = BorderStyle.None;
      richTextBox1.Dock = DockStyle.Top;
      richTextBox1.MinimumSize = new Size(panel1.Width, panel1.Height - 2);
      //initialize some properties for your panel1
      panel1.AutoScroll = true;
      panel1.BorderStyle = BorderStyle.FixedSingle;       
      //If the size of panel1 is changed, we have to update the MinimumSize of richTextBox1.
      panel1.SizeChanged += (s,e) => {
         richTextBox1.MinimumSize = new Size(panel1.Width, panel1.Height - 2);
      };   
      new NativeRichTextBox() { Parent = panel1 }.AssignHandle(richTextBox1.Handle);
      hidden.Parent = panel1;    
   }
   //hidden control of panel1 is used to scroll the thumb when the KeyUp of richTextBox1 is raised.
   Control hidden = new Control();
   //this is used to hook into the message loop of the richTextBox1
   public class NativeRichTextBox : NativeWindow
    {
        public Panel Parent;
        protected override void WndProc(ref Message m)
        {

            if (m.Msg == 0x20a)//WM_MOUSEWHEEL = 0x20a
            {                    
                if (Parent != null)
                {
                    SendMessage(Parent.Handle, m.Msg, m.WParam, m.LParam);                     
                    return;
                }
            }
            base.WndProc(ref m);                
        }
    }
   //ContentsResized event handler of your richTextBox1
   private void richTextBox1_ContentsResized(object sender, ContentsResizedEventArgs e)
    {
        richTextBox1.Height = e.NewRectangle.Height + 5;            
    }
   //KeyUp event handler of your richTextBox1
   private void richTextBox1_KeyUp(object sender, KeyEventArgs e)
    {
            Point p = richTextBox1.GetPositionFromCharIndex(richTextBox1.SelectionStart);                                
            hidden.Top = panel1.PointToClient(richTextBox1.PointToScreen(p)).Y;
            hidden.Height = (int) richTextBox1.SelectionFont.Height;
            panel1.ScrollControlIntoView(hidden);                
    }
}

注意:您必须使用代码或由设计师。