What is the C# version of VB.net's InputDialog?

Add a reference to Microsoft.VisualBasic, InputBox is in the Microsoft.VisualBasic.Interaction namespace:

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

Only the first argument for prompt is mandatory

Dynamic creation of a dialog box. You can customize to your taste.

Note there is no external dependency here except winform

private static DialogResult ShowInputDialog(ref string input)
    {
        System.Drawing.Size size = new System.Drawing.Size(200, 70);
        Form inputBox = new Form();

        inputBox.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedDialog;
        inputBox.ClientSize = size;
        inputBox.Text = "Name";

        System.Windows.Forms.TextBox textBox = new TextBox();
        textBox.Size = new System.Drawing.Size(size.Width - 10, 23);
        textBox.Location = new System.Drawing.Point(5, 5);
        textBox.Text = input;
        inputBox.Controls.Add(textBox);

        Button okButton = new Button();
        okButton.DialogResult = System.Windows.Forms.DialogResult.OK;
        okButton.Name = "okButton";
        okButton.Size = new System.Drawing.Size(75, 23);
        okButton.Text = "&OK";
        okButton.Location = new System.Drawing.Point(size.Width - 80 - 80, 39);
        inputBox.Controls.Add(okButton);

        Button cancelButton = new Button();
        cancelButton.DialogResult = System.Windows.Forms.DialogResult.Cancel;
        cancelButton.Name = "cancelButton";
        cancelButton.Size = new System.Drawing.Size(75, 23);
        cancelButton.Text = "&Cancel";
        cancelButton.Location = new System.Drawing.Point(size.Width - 80, 39);
        inputBox.Controls.Add(cancelButton);

        inputBox.AcceptButton = okButton;
        inputBox.CancelButton = cancelButton; 

        DialogResult result = inputBox.ShowDialog();
        input = textBox.Text;
        return result;
    }

usage

string input="hede";
ShowInputDialog(ref input);

To sum it up:

• There is none in C#.

• You can use the dialog from Visual Basic by adding a reference to Microsoft.VisualBasic:

  1. In Solution Explorer right-click on the References folder.
  2. Select Add Reference...
  3. In the .NET tab (in newer Visual Studio verions - Assembly tab) - select Microsoft.VisualBasic
  4. Click on OK

Then you can use the previously mentioned code:

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

• Write your own InputBox.
• Use someone else's.

That said, I suggest that you consider the need of an input box in the first place. Dialogs are not always the best way to do things and sometimes they do more harm than good - but that depends on the particular situation.