gistfile1.cs

class Derp {
    private System.ComponentModel.BackgroundWorker backgroundWorker;

    public Derp() {
        backgroundWorker = new System.ComponentModel.BackgroundWorker();
        this.backgroundWorker.DoWork += new System.ComponentModel.DoWorkEventHandler(this.backgroundWorker_DoWork);
    }

    public void Herp(string message) {
        backgroundWorker.RunWorkerAsync(message);
    }

    private void backgroundWorker1_DoWork(object sender, System.ComponentModel.DoWorkEventArgs e) {
        System.Windows.MessageBox.Show((string)e.Argument);
    }
}