Unsmooth scrolling

form1.cs

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;

namespace slider
{
    public partial class Form1 : Form
    {
        int _AmountLeft;
        int _Step;

        public Form1( )
        {
            InitializeComponent( );
        }

        private void StartTest_Click( object sender, EventArgs e )
        {
            _AmountLeft = PanelToResize.Width / 2; // half of it
            _Step = _AmountLeft / 10;
            Ticker.Enabled = true;
        }

        private void Ticker_Tick( object sender, EventArgs e )
        {
            int this_bit = Math.Min( _AmountLeft, _Step );
            // reduce
            PanelToResize.Bounds = new Rectangle( PanelToResize.Left + this_bit, PanelToResize.Top, PanelToResize.Width - this_bit, PanelToResize.Height );
            if (this_bit == _AmountLeft)
                Ticker.Enabled = false;
            _AmountLeft -= this_bit;
        }
    }
}

namespace slider
{
    partial class Form1
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose( bool disposing )
        {
            if (disposing && (components != null))
            {
                components.Dispose( );
            }
            base.Dispose( disposing );
        }

        #region Windows Form Designer generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent( )
        {
            this.components = new System.ComponentModel.Container();
            this.PanelToResize = new System.Windows.Forms.Panel();
            this.button1 = new System.Windows.Forms.Button();
            this.button2 = new System.Windows.Forms.Button();
            this.StartTest = new System.Windows.Forms.Button();
            this.Ticker = new System.Windows.Forms.Timer(this.components);
            this.PanelToResize.SuspendLayout();
            this.SuspendLayout();
            // 
            // PanelToResize
            // 
            this.PanelToResize.BackColor = System.Drawing.Color.Red;
            this.PanelToResize.Controls.Add(this.button2);
            this.PanelToResize.Controls.Add(this.button1);
            this.PanelToResize.Location = new System.Drawing.Point(49, 26);
            this.PanelToResize.Name = "PanelToResize";
            this.PanelToResize.Size = new System.Drawing.Size(801, 128);
            this.PanelToResize.TabIndex = 0;
            // 
            // button1
            // 
            this.button1.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Right)));
            this.button1.Location = new System.Drawing.Point(602, 36);
            this.button1.Name = "button1";
            this.button1.Size = new System.Drawing.Size(72, 37);
            this.button1.TabIndex = 0;
            this.button1.Text = "button1";
            this.button1.UseVisualStyleBackColor = true;
            // 
            // button2
            // 
            this.button2.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Right)));
            this.button2.Location = new System.Drawing.Point(708, 37);
            this.button2.Name = "button2";
            this.button2.Size = new System.Drawing.Size(66, 35);
            this.button2.TabIndex = 1;
            this.button2.Text = "button2";
            this.button2.UseVisualStyleBackColor = true;
            // 
            // StartTest
            // 
            this.StartTest.Location = new System.Drawing.Point(49, 170);
            this.StartTest.Name = "StartTest";
            this.StartTest.Size = new System.Drawing.Size(89, 35);
            this.StartTest.TabIndex = 1;
            this.StartTest.Text = "Start";
            this.StartTest.UseVisualStyleBackColor = true;
            this.StartTest.Click += new System.EventHandler(this.StartTest_Click);
            // 
            // Ticker
            // 
            this.Ticker.Interval = 50;
            this.Ticker.Tick += new System.EventHandler(this.Ticker_Tick);
            // 
            // Form1
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(901, 323);
            this.Controls.Add(this.StartTest);
            this.Controls.Add(this.PanelToResize);
            this.Name = "Form1";
            this.Text = "Form1";
            this.PanelToResize.ResumeLayout(false);
            this.ResumeLayout(false);

        }

        #endregion

        private System.Windows.Forms.Panel PanelToResize;
        private System.Windows.Forms.Button button2;
        private System.Windows.Forms.Button button1;
        private System.Windows.Forms.Button StartTest;
        private System.Windows.Forms.Timer Ticker;
    }
}