Mod_rewrite GUI

The simplest way is an anonymous method passed into Label.Invoke:

// Running on the worker thread
string newText = "abc";
form.Label.Invoke((MethodInvoker)delegate {
    // Running on the UI thread
    form.Label.Text = newText;
});
// Back on the worker thread

Notice that Invoke blocks execution until it completes--this is synchronous code. The question doesn't ask about asynchronous code, but there is lots of content on Stack Overflow about writing asynchronous code when you want to learn about it.

In order to use mod_rewrite you can type the following command in the terminal:

sudo a2enmod rewrite

Restart apache2 after

sudo /etc/init.d/apache2 restart

or

sudo service apache2 restart

or as per new unified System Control Way

sudo systemctl restart apache2

Then, if you'd like, you can use the following .htaccess file.

<IfModule mod_rewrite.c>
    RewriteEngine On
    RewriteBase /
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteRule . /index.php [L]
</IfModule>

The above .htaccess file (if placed in your DocumentRoot) will redirect all traffic to an index.php file in the DocumentRoot unless the file exists.

So, let's say you have the following directory structure and httpdocs is the DocumentRoot

httpdocs/
    .htaccess
    index.php
    images/
        hello.png
    js/
        jquery.js
    css/
        style.css
includes/
    app/
        app.php

Any file that exists in httpdocs will be served to the requester using the .htaccess shown above, however, everything else will be redirected to httpdocs/index.php. Your application files in includes/app will not be accessible.