c# InputBox

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

namespace WindowsApplication1
{

 #region InputBox return result

 /// <summary>
 /// Class used to store the result of an InputBox.Show message.
 /// </summary>
 public class InputBoxResult
 {
  public DialogResult ReturnCode;
  public string Text;
 }

 #endregion

 /// <summary>
 /// Summary description for InputBox.
 /// </summary>
 public class InputBox
 {

  #region Private Windows Contols and Constructor

  // Create a new instance of the form.
  private static Form frmInputDialog;
  private static Label lblPrompt;
  private static Button btnOK;
  private static Button btnCancel;
  private static TextBox txtInput;

  public InputBox()
  {
  }

  #endregion

  #region Private Variables

  private static string _formCaption = string.Empty;
  private static string _formPrompt = string.Empty;
  private static InputBoxResult _outputResponse = new InputBoxResult();
  private static string _defaultValue = string.Empty;
  private static int _xPos = -1;
  private static int _yPos = -1;

  #endregion

  #region Windows Form code

  private static void InitializeComponent()
  {
   // Create a new instance of the form.
   frmInputDialog = new Form();
   lblPrompt = new Label();
   btnOK = new Button();
   btnCancel = new Button();
   txtInput = new TextBox();
   frmInputDialog.SuspendLayout();
   //
   // lblPrompt
   //
   lblPrompt.Anchor = ((AnchorStyles)((((AnchorStyles.Top | AnchorStyles.Bottom) | AnchorStyles.Left) | AnchorStyles.Right)));
   lblPrompt.BackColor = SystemColors.Control;
   lblPrompt.Font = new Font("Microsoft Sans Serif", 8.25F, FontStyle.Regular, GraphicsUnit.Point, ((Byte)(0)));
   lblPrompt.Location = new Point(12, 9);
   lblPrompt.Name = "lblPrompt";
   lblPrompt.Size = new Size(302, 82);
   lblPrompt.TabIndex = 3;
   //
   // btnOK
   //
   btnOK.DialogResult = DialogResult.OK;
   btnOK.FlatStyle = FlatStyle.Popup;
   btnOK.Location = new Point(326, 8);
   btnOK.Name = "btnOK";
   btnOK.Size = new Size(64, 24);
   btnOK.TabIndex = 1;
   btnOK.Text = "&OK";
   btnOK.Click += new EventHandler(btnOK_Click);
   //
   // btnCancel
   //
   btnCancel.DialogResult = DialogResult.Cancel;
   btnCancel.FlatStyle = FlatStyle.Popup;
   btnCancel.Location = new Point(326, 40);
   btnCancel.Name = "btnCancel";
   btnCancel.Size = new Size(64, 24);
   btnCancel.TabIndex = 2;
   btnCancel.Text = "&Cancel";
   btnCancel.Click += new EventHandler(btnCancel_Click);
   //
   // txtInput
   //
   txtInput.Location = new Point(8, 100);
   txtInput.Name = "txtInput";
   txtInput.Size = new Size(379, 20);
   txtInput.TabIndex = 0;
   txtInput.Text = "";
   //
   // InputBoxDialog
   //
   frmInputDialog.AutoScaleBaseSize = new Size(5, 13);
   frmInputDialog.ClientSize = new Size(398, 128);
   frmInputDialog.Controls.Add(txtInput);
   frmInputDialog.Controls.Add(btnCancel);
   frmInputDialog.Controls.Add(btnOK);
   frmInputDialog.Controls.Add(lblPrompt);
   frmInputDialog.FormBorderStyle = FormBorderStyle.FixedDialog;
   frmInputDialog.MaximizeBox = false;
   frmInputDialog.MinimizeBox = false;
   frmInputDialog.Name = "InputBoxDialog";
   frmInputDialog.ResumeLayout(false);
  }

  #endregion

  #region Private function, InputBox Form move and change size

  static private void LoadForm()
  {
   OutputResponse.ReturnCode = DialogResult.Ignore;
   OutputResponse.Text = string.Empty;

   txtInput.Text = _defaultValue;
   lblPrompt.Text = _formPrompt;
   frmInputDialog.Text = _formCaption;

   // Retrieve the working rectangle from the Screen class
   // using the PrimaryScreen and the WorkingArea properties.
   System.Drawing.Rectangle workingRectangle = Screen.PrimaryScreen.WorkingArea;

   if((_xPos >= 0 && _xPos < workingRectangle.Width-100) && (_yPos >= 0 && _yPos < workingRectangle.Height-100))
   {
    frmInputDialog.StartPosition = FormStartPosition.Manual;
        frmInputDialog.Location = new System.Drawing.Point(_xPos, _yPos);
   }
   else
    frmInputDialog.StartPosition = FormStartPosition.CenterScreen;

   string PrompText = lblPrompt.Text;

   int n = 0;
   int Index = 0;
   while(PrompText.IndexOf("\n",Index) > -1)
   {
    Index = PrompText.IndexOf("\n",Index)+1;
    n++;
   }

   if( n == 0 )
    n = 1;

   System.Drawing.Point Txt = txtInput.Location;
   Txt.Y = Txt.Y + (n*4);
   txtInput.Location = Txt;
   System.Drawing.Size form = frmInputDialog.Size;
   form.Height = form.Height + (n*4);
   frmInputDialog.Size = form;

   txtInput.SelectionStart = 0;
   txtInput.SelectionLength = txtInput.Text.Length;
   txtInput.Focus();
  }

  #endregion

  #region Button control click event

  static private void btnOK_Click(object sender, System.EventArgs e)
  {
   OutputResponse.ReturnCode = DialogResult.OK;
   OutputResponse.Text = txtInput.Text;
   frmInputDialog.Dispose();
  }

  static private void btnCancel_Click(object sender, System.EventArgs e)
  {
   OutputResponse.ReturnCode = DialogResult.Cancel;
   OutputResponse.Text = string.Empty; //Clean output response
   frmInputDialog.Dispose();
  }

  #endregion

  #region Public Static Show functions

  static public InputBoxResult Show(string Prompt)
  {
   InitializeComponent();
   FormPrompt = Prompt;

   // Display the form as a modal dialog box.
   LoadForm();
   frmInputDialog.ShowDialog();
   return OutputResponse;
  }

  static public InputBoxResult Show(string Prompt,string Title)
  {
   InitializeComponent();

   FormCaption = Title;
   FormPrompt = Prompt;

   // Display the form as a modal dialog box.
   LoadForm();
   frmInputDialog.ShowDialog();
   return OutputResponse;
  }

  static public InputBoxResult Show(string Prompt,string Title,string Default)
  {
   InitializeComponent();

   FormCaption = Title;
   FormPrompt = Prompt;
   DefaultValue = Default;

   // Display the form as a modal dialog box.
   LoadForm();
   frmInputDialog.ShowDialog();
   return OutputResponse;
  }

  static public InputBoxResult Show(string Prompt,string Title,string Default,int XPos,int YPos)
  {
   InitializeComponent();
   FormCaption = Title;
   FormPrompt = Prompt;
   DefaultValue = Default;
   XPosition = XPos;
   YPosition = YPos;

   // Display the form as a modal dialog box.
   LoadForm();
   frmInputDialog.ShowDialog();
   return OutputResponse;
  }

  #endregion

  #region Private Properties

  static private string FormCaption
  {
   set
   {
    _formCaption = value;
   }
  } // property FormCaption
  
  static private string FormPrompt
  {
   set
   {
    _formPrompt = value;
   }
  } // property FormPrompt
  
  static private InputBoxResult OutputResponse
  {
   get
   {
    return _outputResponse;
   }
   set
   {
    _outputResponse = value;
   }
  } // property InputResponse
  
  static private string DefaultValue
  {
   set
   {
    _defaultValue = value;
   }
  } // property DefaultValue

  static private int XPosition
  {
   set
   {
    if( value >= 0 )
     _xPos = value;
   }
  } // property XPos

  static private int YPosition
  {
   set
   {
    if( value >= 0 )
     _yPos = value;
   }
  } // property YPos

  #endregion
 }
}