title: Question about an event perculiarity in a TabControl
body: <p>I have a little demonstration below of a peculiar problem.</p>
  
  <pre><code>using System;
  using System.Windows.Forms;
  
  namespace WindowsApplication1
  {
      public class TestForm : Form
      {
          private System.Windows.Forms.TabControl tabControl1;
          private System.Windows.Forms.TabPage tabPage1;
          private System.Windows.Forms.TabPage tabPage2;
          private System.Windows.Forms.TextBox textBox1;
  
          public TestForm()
          {
              //Controls
              this.tabControl1 = new System.Windows.Forms.TabControl();
              this.tabPage1 = new System.Windows.Forms.TabPage();
              this.tabPage2 = new System.Windows.Forms.TabPage();
              this.textBox1 = new System.Windows.Forms.TextBox();
  
              // tabControl1
              this.tabControl1.Anchor = ((System.Windows.Forms.AnchorStyles)((((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom)
                          | System.Windows.Forms.AnchorStyles.Left)
                          | System.Windows.Forms.AnchorStyles.Right)));
              this.tabControl1.Controls.Add(this.tabPage1);
              this.tabControl1.Controls.Add(this.tabPage2);
              this.tabControl1.Location = new System.Drawing.Point(12, 12);
              this.tabControl1.Name = "tabControl1";
              this.tabControl1.SelectedIndex = 0;
              this.tabControl1.Size = new System.Drawing.Size(260, 240);
              this.tabControl1.TabIndex = 0;
              this.tabControl1.Selected += new System.Windows.Forms.TabControlEventHandler(this.tabControl1_Selected);
  
              // tabPage1
              this.tabPage1.Controls.Add(this.textBox1);
              this.tabPage1.Location = new System.Drawing.Point(4, 22);
              this.tabPage1.Name = "tabPage1";
              this.tabPage1.Size = new System.Drawing.Size(252, 214);
              this.tabPage1.TabIndex = 0;
              this.tabPage1.Text = "tabPage1";
  
              // tabPage2
              this.tabPage2.Location = new System.Drawing.Point(4, 22);
              this.tabPage2.Name = "tabPage2";
              this.tabPage2.Size = new System.Drawing.Size(192, 74);
              this.tabPage2.TabIndex = 1;
              this.tabPage2.Text = "tabPage2";
  
              // textBox1
              this.textBox1.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left)
                          | System.Windows.Forms.AnchorStyles.Right)));
              this.textBox1.Location = new System.Drawing.Point(6, 38);
              this.textBox1.Name = "textBox1";
              this.textBox1.Size = new System.Drawing.Size(240, 20);
              this.textBox1.TabIndex = 0;
  
              // TestForm
              this.ClientSize = new System.Drawing.Size(284, 264);
              this.Controls.Add(this.tabControl1);
              this.Name = "Form1";
              this.Text = "Form1";
          }
  
          //Tab Selected
          private void tabControl1_Selected(object sender, EventArgs e)
          {
              this.Text = "TextBox Width: " + this.textBox1.Width.ToString();
          }
      }
  
      //Main
      static class Program
      {
          static void Main()
          {
              Application.Run(new TestForm());
          }
      }
  
  }
  </code></pre>
  
  <p>If you run the above C# code you will have a small form containing a tabcontrol. Within the tabcontrol is a texbox on the first tab. If you follow these steps you will see the problem:</p>
  
  <ol>
  <li>Select tabPage2 (textBox1's width is reported in the form title)</li>
  <li>Resize the form</li>
  <li>Select tabPage1 (The wrong textBox1 width is reported)</li>
  </ol>
  
  <p>Any ideas what is going on here? The textbox is obviously bigger than what is being reported. If you click again on tabPage2 the correct size is then updated. Obviously there is an event updating the width of textBox1. Can i trigger this when tabPage1 is selected?</p>