Tarn Barford

I just read the latest post from secretGeek, a brilliantly funny blog which often makes my day with posts like IT Industry Revolutionised By Labour Saving Device and Defensive Programming.

The latest post, A 3 minute guide to embedding IronPython in a C# application, is a demo of a Windows application that can execute an IronPython script from a TextBox at runtime. Another TextBox control on the form is added to the IronPython script scope so the script can interact with it. This is both cool and powerful, the concept has been used in an IronPython powered spreadsheet from Revolver Systems.

I thought it would be kind of fun to create an IronPython script that created a Windows Form which could execute a script. This means I could run the script and get window which I could then use to run the script again and get anther window, then..

I posted the script in the comments and then decided it was pretty fun and it would be worth writing a post about myself. Below is the Form class script:

import clr
clr.AddReferenceByPartialName("System.Windows.Forms")
clr.AddReference('IronPython')
clr.AddReference('Microsoft.Scripting')

from System.Windows.Forms import *
from IronPython.Hosting import Python
from Microsoft.Scripting import SourceCodeKind

class MetaNote(Form):

    def __init__(self):
    self.button = Button()
    self.code = TextBox()
    self.text = TextBox()
    self.Width = 420
    self.Height = 400
    self.code.Multiline = True
    self.code.Height = 300
    self.code.Width = 300;
    self.button.Left = 310
    self.button.Text = "Execute"

    self.Controls.Add(self.button)
    self.Controls.Add(self.code)
    self.button.Click += self.run

def run(self,sender,e):

    engine = Python.CreateEngine()
    source = engine.CreateScriptSourceFromString(self.code.Text,SourceCodeKind.Statements)
    scope = engine.CreateScope()
    scope.SetVariable("txt", self.text);
    source.Execute(scope)

The only trick is, to start the application from the IronPython console (ipy.exe) you need to include this line at the end which creates the class and creates a standard application message loop.

Application.Run(MetaNote())

When the script is executed from within the application itself, you only need to create in instance of the class and call its Show method.

MetaNote().Show()

Then the fun..

Executing IronPython in, err.. IronPython