Prompt Dialog in Windows Forms

Question

You need to create your own Prompt dialog. You could perhaps create a class for this.

public static class Prompt
{
    public static string ShowDialog(string text, string caption)
    {
        Form prompt = new Form()
        {
            Width = 500,
            Height = 150,
            FormBorderStyle = FormBorderStyle.FixedDialog,
            Text = caption,
            StartPosition = FormStartPosition.CenterScreen
        };
        Label textLabel = new Label() { Left = 50, Top=20, Text=text };
        TextBox textBox = new TextBox() { Left = 50, Top=50, Width=400 };
        Button confirmation = new Button() { Text = "Ok", Left=350, Width=100, Top=70, DialogResult = DialogResult.OK };
        confirmation.Click += (sender, e) => { prompt.Close(); };
        prompt.Controls.Add(textBox);
        prompt.Controls.Add(confirmation);
        prompt.Controls.Add(textLabel);
        prompt.AcceptButton = confirmation;

        return prompt.ShowDialog() == DialogResult.OK ? textBox.Text : "";
    }
}

And calling it:

string promptValue = Prompt.ShowDialog("Test", "123");

Update:

Added default button (enter key) and initial focus based on comments and another question.

Add reference to Microsoft.VisualBasic and use this into your C# code:

string input = Microsoft.VisualBasic.Interaction.InputBox("Prompt", 
                       "Title", 
                       "Default", 
                       0, 
                       0);

To add the refernce: right-click on the References in your Project Explorer window then on Add Reference, and check VisualBasic from that list.

There is no such thing natively in Windows Forms.

You have to create your own form for that or:

use the Microsoft.VisualBasic reference.

Inputbox is legacy code brought into .Net for VB6 compatibility - so i advise to not do this.

It's generally not a real good idea to import the VisualBasic libraries into C# programs (not because they won't work, but just for compatibility, style, and ability to upgrade), but you can call Microsoft.VisualBasic.Interaction.InputBox() to display the kind of box you're looking for.

If you can create a Windows.Forms object, that would be best, but you say you cannot do that.

The answer of Bas can get you in memorytrouble theoretically, since ShowDialog won't be disposed. I think this is a more proper way. Also mention the textLabel being readable with longer text.

public class Prompt : IDisposable
{
    private Form prompt { get; set; }
    public string Result { get; }

    public Prompt(string text, string caption)
    {
        Result = ShowDialog(text, caption);
    }
    //use a using statement
    private string ShowDialog(string text, string caption)
    {
        prompt = new Form()
        {
            Width = 500,
            Height = 150,
            FormBorderStyle = FormBorderStyle.FixedDialog,
            Text = caption,
            StartPosition = FormStartPosition.CenterScreen,
            TopMost = true
        };
        Label textLabel = new Label() { Left = 50, Top = 20, Text = text, Dock = DockStyle.Top, TextAlign = ContentAlignment.MiddleCenter };
        TextBox textBox = new TextBox() { Left = 50, Top = 50, Width = 400 };
        Button confirmation = new Button() { Text = "Ok", Left = 350, Width = 100, Top = 70, DialogResult = DialogResult.OK };
        confirmation.Click += (sender, e) => { prompt.Close(); };
        prompt.Controls.Add(textBox);
        prompt.Controls.Add(confirmation);
        prompt.Controls.Add(textLabel);
        prompt.AcceptButton = confirmation;

        return prompt.ShowDialog() == DialogResult.OK ? textBox.Text : "";
    }

    public void Dispose()
    {
        //See Marcus comment
        if (prompt != null) { 
            prompt.Dispose(); 
        }
    }
}

Implementation:

using(Prompt prompt = new Prompt("text", "caption")){
    string result = prompt.Result;
}

Other way of doing this: Assuming that you have a TextBox input type, Create a Form, and have the textbox value as a public property.

public partial class TextPrompt : Form
{
    public string Value
    {
        get { return tbText.Text.Trim(); }
    }

    public TextPrompt(string promptInstructions)
    {
        InitializeComponent();

        lblPromptText.Text = promptInstructions;
    }

    private void BtnSubmitText_Click(object sender, EventArgs e)
    {
        Close();
    }

    private void TextPrompt_Load(object sender, EventArgs e)
    {
        CenterToParent();
    }
}

In the main form, this will be the code:

var t = new TextPrompt(this, "Type the name of the settings file:");
t.ShowDialog()

;

This way, the code looks cleaner:

1. If validation logic is added.
2. If various other input types are added.

Based on the work of Bas Brekelmans above, I have also created two derivations -> "input" dialogs that allow you to receive from the user both a text value and a boolean (TextBox and CheckBox):

public static class PromptForTextAndBoolean
{
    public static string ShowDialog(string caption, string text, string boolStr)
    {
        Form prompt = new Form();
        prompt.Width = 280;
        prompt.Height = 160;
        prompt.Text = caption;
        Label textLabel = new Label() { Left = 16, Top = 20, Width = 240, Text = text };
        TextBox textBox = new TextBox() { Left = 16, Top = 40, Width = 240, TabIndex = 0, TabStop = true };
        CheckBox ckbx = new CheckBox() { Left = 16, Top = 60, Width = 240, Text = boolStr };
        Button confirmation = new Button() { Text = "Okay!", Left = 16, Width = 80, Top = 88, TabIndex = 1, TabStop = true };
        confirmation.Click += (sender, e) => { prompt.Close(); };
        prompt.Controls.Add(textLabel);
        prompt.Controls.Add(textBox);
        prompt.Controls.Add(ckbx);
        prompt.Controls.Add(confirmation);
        prompt.AcceptButton = confirmation;
        prompt.StartPosition = FormStartPosition.CenterScreen;
        prompt.ShowDialog();
        return string.Format("{0};{1}", textBox.Text, ckbx.Checked.ToString());
    }
}

...and text along with a selection of one of multiple options (TextBox and ComboBox):

public static class PromptForTextAndSelection
{
    public static string ShowDialog(string caption, string text, string selStr)
    {
        Form prompt = new Form();
        prompt.Width = 280;
        prompt.Height = 160;
        prompt.Text = caption;
        Label textLabel = new Label() { Left = 16, Top = 20, Width = 240, Text = text };
        TextBox textBox = new TextBox() { Left = 16, Top = 40, Width = 240, TabIndex = 0, TabStop = true };
        Label selLabel = new Label() { Left = 16, Top = 66, Width = 88, Text = selStr };
        ComboBox cmbx = new ComboBox() { Left = 112, Top = 64, Width = 144 };
        cmbx.Items.Add("Dark Grey");
        cmbx.Items.Add("Orange");
        cmbx.Items.Add("None");
        Button confirmation = new Button() { Text = "In Ordnung!", Left = 16, Width = 80, Top = 88, TabIndex = 1, TabStop = true };
        confirmation.Click += (sender, e) => { prompt.Close(); };
        prompt.Controls.Add(textLabel);
        prompt.Controls.Add(textBox);
        prompt.Controls.Add(selLabel);
        prompt.Controls.Add(cmbx);
        prompt.Controls.Add(confirmation);
        prompt.AcceptButton = confirmation;
        prompt.StartPosition = FormStartPosition.CenterScreen;
        prompt.ShowDialog();
        return string.Format("{0};{1}", textBox.Text, cmbx.SelectedItem.ToString());
    }
}

Both require the same usings:

using System;
using System.Windows.Forms;

Call them like so:

Call them like so:

PromptForTextAndBoolean.ShowDialog("Jazz", "What text should accompany the checkbox?", "Allow Scat Singing"); 

PromptForTextAndSelection.ShowDialog("Rock", "What should the name of the band be?", "Beret color to wear");