To subscribe both events use this code:
public Form1()
{
InitializeComponent();
this.radioButton1.Click += new System.EventHandler(this.radioButton_Click);
this.radioButton2.Click += new System.EventHandler(this.radioButton_Click);
}
To handle the events this should work:
private void radioButton_Click(object sender, EventArgs e)
{
if ((RadioButton)sender == radioButton1)
{
}
else
{
}
}