KnowDotNet

Create A VB InputBox in C#

Borrow an Idea From a VB Time Saver

by Les Smith

Why doesn't C# have something like VB's InputBox.  If I have to prompt the user for one piece of data, it's a real pain to have to create a special dialog to get it?  

One C# "guru" remarked that VB programmers are pampered.  With over 11 years of VB and VB.NET behind me, I agree, but with pleasure.  Although the majority of my current work is now done in C#, I find myself missing some of the nicities that were a given in VB and VB.NET.

I a need to use a VB Input Box throughout the client side of a large .NET Remoting project, on which I am working.  So I created a C# InputBox Dialog in C#.  This article will show you how it looks and give you the code for it.  Figure 1 shows the looks of the dialog.  I hope it looks close to the InputBox look.

Figure 1 - InputBox Dialog.

InputBox Dialog


The code to call the C# InputBox is shown in Figure 2.  You only need to supply the Prompt, Title, and Default Input, just as you would in using the VB Input Box.

Figure 2 - Calling the InputBox

  /// <summary>
  /// Replacement for VB InputBox, returns user input string.
  ///
  ///
  ///
  ///
  /// <returns>string
  public static string InputBox(string prompt,
    string title, string defaultValue)
  {
    InputBoxDialog ib = new InputBoxDialog();
    ib.FormPrompt = prompt;
    ib.FormCaption = title;
    ib.DefaultValue = defaultValue;
    ib.ShowDialog();
    string s = ib.InputResponse;
    ib.Close();
    return s;
  } // method: InputBox

Though it may be a bit boring, in case you may want the code, it is shown in Figure 3 and can be copied from this page to your blank class.

Figure 3 - C# Code for InputBox.

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

namespace DocuTrackProSE
{
  /// <summary>
  /// Summary description for InputBox.
  ///
  public class InputBoxDialog : System.Windows.Forms.Form
  {

    #region Windows Contols and Constructor

    private System.Windows.Forms.Label lblPrompt;
    private System.Windows.Forms.Button btnOK;
    private System.Windows.Forms.Button button1;
    private System.Windows.Forms.TextBox txtInput;
    /// <summary>
    /// Required designer variable.
    ///
    private System.ComponentModel.Container components = null;

    public InputBoxDialog()
    {
      //
      // Required for Windows Form Designer support
      //
      InitializeComponent();

      //
      // TODO: Add any constructor code after InitializeComponent call
      //
    }

    #endregion

    #region Dispose

    /// <summary>
    /// Clean up any resources being used.
    ///
    protected override void Dispose( bool disposing )
    {
      if( disposing )
      {
        if(components != null)
        {
          components.Dispose();
        }
      }
      base.Dispose( disposing );
    }

    #endregion

    #region Windows Form Designer generated code
    /// <summary>
    /// Required method for Designer support - do not modify
    /// the contents of this method with the code editor.
    ///
    private void InitializeComponent()
    {
      this.lblPrompt = new System.Windows.Forms.Label();
      this.btnOK = new System.Windows.Forms.Button();
      this.button1 = new System.Windows.Forms.Button();
      this.txtInput = new System.Windows.Forms.TextBox();
      this.SuspendLayout();
      //
      // lblPrompt
      //
      this.lblPrompt.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.lblPrompt.BackColor = System.Drawing.SystemColors.Control;
      this.lblPrompt.Font =
        new System.Drawing.Font("Microsoft Sans Serif", 9.75F,
        System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point,
        ((System.Byte)(0)));
      this.lblPrompt.Location = new System.Drawing.Point(12, 9);
      this.lblPrompt.Name = "lblPrompt";
      this.lblPrompt.Size = new System.Drawing.Size(302, 82);
      this.lblPrompt.TabIndex = 3;
      //
      // btnOK
      //
      this.btnOK.DialogResult = System.Windows.Forms.DialogResult.OK;
      this.btnOK.FlatStyle = System.Windows.Forms.FlatStyle.Popup;
      this.btnOK.Location = new System.Drawing.Point(326, 24);
      this.btnOK.Name = "btnOK";
      this.btnOK.Size = new System.Drawing.Size(64, 24);
      this.btnOK.TabIndex = 1;
      this.btnOK.Text = "&OK";
      this.btnOK.Click += new System.EventHandler(this.btnOK_Click);
      //
      // button1
      //
      this.button1.DialogResult = System.Windows.Forms.DialogResult.Cancel;
      this.button1.FlatStyle = System.Windows.Forms.FlatStyle.Popup;
      this.button1.Location = new System.Drawing.Point(326, 56);
      this.button1.Name = "button1";
      this.button1.Size = new System.Drawing.Size(64, 24);
      this.button1.TabIndex = 2;
      this.button1.Text = "&Cancel";
      this.button1.Click += new System.EventHandler(this.button1_Click);
      //
      // txtInput
      //
      this.txtInput.Location = new System.Drawing.Point(8, 100);
      this.txtInput.Name = "txtInput";
      this.txtInput.Size = new System.Drawing.Size(379, 20);
      this.txtInput.TabIndex = 0;
      this.txtInput.Text = "";
      //
      // InputBoxDialog
      //
      this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
      this.ClientSize = new System.Drawing.Size(398, 128);
      this.Controls.Add(this.txtInput);
      this.Controls.Add(this.button1);
      this.Controls.Add(this.btnOK);
      this.Controls.Add(this.lblPrompt);
      this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedDialog;
      this.MaximizeBox = false;
      this.MinimizeBox = false;
      this.Name = "InputBoxDialog";
      this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
      this.Text = "InputBox";
      this.Load += new System.EventHandler(this.InputBox_Load);
      this.ResumeLayout(false);

    }
    #endregion

    #region Private Variables
    string formCaption = string.Empty;
    string formPrompt = string.Empty;
    string inputResponse = string.Empty;
    string defaultValue = string.Empty;
    #endregion

    #region Public Properties
    public string FormCaption
    {
      get{return formCaption;}
      set{formCaption = value;}
    } // property FormCaption
    public string FormPrompt
    {
      get{return formPrompt;}
      set{formPrompt = value;}
    } // property FormPrompt
    public string InputResponse
    {
      get{return inputResponse;}
      set{inputResponse = value;}
    } // property InputResponse
    public string DefaultValue
    {
      get{return defaultValue;}
      set{defaultValue = value;}
    } // property DefaultValue

    #endregion

    #region Form and Control Events
    private void InputBox_Load(object sender, System.EventArgs e)
    {
      this.txtInput.Text=defaultValue;
      this.lblPrompt.Text=formPrompt;
      this.Text=formCaption;
      this.txtInput.SelectionStart=0;
      this.txtInput.SelectionLength=this.txtInput.Text.Length;
      this.txtInput.Focus();
    }


    private void btnOK_Click(object sender, System.EventArgs e)
    {
      InputResponse = this.txtInput.Text;
      this.Close();
    }

    private void button1_Click(object sender, System.EventArgs e)
    {
      this.Close();
    }
    #endregion


  }
}