title: How to remove all ListBox items?
body: <p>I created two RadioButton (Weight and Height). I will do switch between the two categories. But the they share the same ListBox Controllers (listBox1 and listBox2).</p>
  
  <p>Is there any good method to clear all the ListBox items simpler? I didn't find the removeAll() for ListBox. I don't like my complex multi-lines style which I posted here.</p>
  
  <pre><code>private void Weight_Click(object sender, RoutedEventArgs e)
      {
          // switch between the radioButton "Weith" and "Height"
          // Clear all the items first
          listBox1.Items.Remove("foot"); 
          listBox1.Items.Remove("inch");
          listBox1.Items.Remove("meter");
          listBox2.Items.Remove("foot");
          listBox2.Items.Remove("inch");
          listBox2.Items.Remove("meter");
  
          // Add source units items for listBox1
          listBox1.Items.Add("kilogram");
          listBox1.Items.Add("pound");
  
          // Add target units items for listBox2
          listBox2.Items.Add("kilogram");
          listBox2.Items.Add("pound");
      }
  
      private void Height_Click(object sender, RoutedEventArgs e)
      {
          // switch between the radioButton "Weith" and "Height"
          // Clear all the items first
          listBox1.Items.Remove("kilogram");
          listBox1.Items.Remove("pound");
          listBox2.Items.Remove("kilogram");
          listBox2.Items.Remove("pound");
  
          // Add source units items for listBox1
          listBox1.Items.Add("foot");
          listBox1.Items.Add("inch");
          listBox1.Items.Add("meter");
  
          // Add target units items for listBox2
          listBox2.Items.Add("foot");
          listBox2.Items.Add("inch");
          listBox2.Items.Add("meter");
      }
  </code></pre>