C#

const int SB_VERT = 1; 
 
const int EM_SETSCROLLPOS = 0x0400 + 222; 



[DllImport("user32", CharSet=CharSet.Auto)] 

public static extern bool GetScrollRange(IntPtr hWnd, int nBar, out int lpMinPos, out int lpMaxPos); 



[DllImport("user32", CharSet=CharSet.Auto)] 

public static extern IntPtr SendMessage(IntPtr hWnd, int msg, int wParam, POINT lParam); 



[StructLayout(LayoutKind.Sequential)] 

public class POINT 

{ 

  public int x; 

  public int y; 



  public POINT() 

  { 

  } 



  public POINT(int x, int y) 

  { 

       this.x = x; 

       this.y = y; 

  } 

} 



// Example -- scroll the RTB so the bottom of the text is always visible. 

int min, max; 

GetScrollRange(richTextBox1.Handle, SB_VERT, out min, out max); 

SendMessage(richTextBox1.Handle, EM_SETSCROLLPOS, 0, new POINT(0, max - richTextBox1.Height)); 

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;

namespace WindowsApplication1
{
	/// <summary>
	/// Form2 
	/// </summary>
	public class Form2 : System.Windows.Forms.Form
	{
		/// <summary>
		/// 
		/// </summary>
		private System.ComponentModel.Container components = null;

		public Form2()
		{
			//
			// 
			//
			InitializeComponent();

			//
			// TODO: InitializeComponent 
			//
		}

		/// <summary>
		/// 
		/// </summary>
		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if(components != null)
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}

		#region Windows フォーム デザイナで生成されたコード 
		/// <summary>
		
		/// </summary>
		private void InitializeComponent()
		{
			this.button1 = new System.Windows.Forms.Button();
			this.SuspendLayout();
			// 
			// button1
			// 
			this.button1.BackColor = System.Drawing.SystemColors.Window;
			this.button1.Cursor = System.Windows.Forms.Cursors.IBeam;
			this.button1.ForeColor = System.Drawing.SystemColors.WindowText;
			this.button1.Location = new System.Drawing.Point(136, 96);
			this.button1.Name = "button1";
			this.button1.Size = new System.Drawing.Size(104, 88);
			this.button1.TabIndex = 7;
			this.button1.Text = "button1";
			this.button1.MouseUp += new System.Windows.Forms.MouseEventHandler(this.button1_MouseUp);
			this.button1.MouseMove += new System.Windows.Forms.MouseEventHandler(this.button1_MouseMove);
			this.button1.MouseDown += new System.Windows.Forms.MouseEventHandler(this.button1_MouseDown);
			// 
			// Form2
			// 
			this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
			this.ClientSize = new System.Drawing.Size(608, 382);
			this.Controls.Add(this.button1);
			this.Name = "Form2";
			this.Text = "Form2";
			this.ResumeLayout(false);

		}
		#endregion

		
		[STAThread]
		static void Main() { Application.Run(new Form2()); }

		private System.Windows.Forms.Button button1;

		int MoveFlag = 0;
		

		private void button1_MouseDown(object sender,
			System.Windows.Forms.MouseEventArgs e)
		{
			MoveFlag = 1;
		}
		// Set some flag to indicate that you are no longer in drag mode on the
		//    mouse up event
		private void button1_MouseUp(object sender,
			System.Windows.Forms.MouseEventArgs e)
		{
			MoveFlag = 0;
		}
		// Reset the location of the button object to equal its current location
		//    plus the new location offset. Since the MouseEventArg returns the client
		//    coordinates you can just add these numbers
		private void button1_MouseMove(object sender,
			System.Windows.Forms.MouseEventArgs e)
		{
			if (MoveFlag == 1)
			{
				button1.Location = (new Point(button1.Location.X+e.X,
					button1.Location.Y+e.Y));
				button1.Refresh();
			}
		}

		

	}
}