/// <summary> /// /// </summary> /// <param name="sender"></param> /// <param name="e"></param> public virtual void SetTextBoxOnEnterStyle(object sender, EventArgs e) {     if (sender is TextBox)     {  TextBox tbox = sender as TextBox;  if (!tbox.ReadOnly)  {      tbox.BackColor = Color.Yellow;  }     } } /// <summary> /// /// </summary> /// <param name="sender"></param> /// <param name="e"></param> public virtual void SetTextBoxOnLeaveStyle(object sender, EventArgs e) {     if (sender is TextBox)     {  TextBox tbox = sender as TextBox;  if (!tbox.ReadOnly)  {      tbox.BackColor = Color.White;  }     } } /// <summary> /// /// </summary> /// <param name="frm"></param> public virtual void SetFormTextBoxControlStyle(Form frm) {     IterateControlsSetTextBox(frm.Controls); } /// <summary> /// /// </summary> /// <param name="ctls"></param> public virtual void IterateControlsSetTextBox(Control.ControlCollection ctls) {     foreach (Control control in ctls)     {  if (control is TextBox)  {      (control as TextBox).Enter += new EventHandler(SetTextBoxOnEnterStyle);      (control as TextBox).Leave += new EventHandler(SetTextBoxOnLeaveStyle);  }  if (control.Controls.Count > 0)  {      IterateControlsSetTextBox(control.Controls);  }     } }