title: How to change textblock background?
body: <p>This is my <code>xaml structure</code></p>
  
  <pre><code>&lt;stackpanel&gt;
    &lt;textblock Text="A"&gt;&lt;/textblock&gt;
    &lt;textblock Text="B"&gt;&lt;/textblock&gt;
  &lt;/stackpanel&gt;
  </code></pre>
  
  <p><code>Stackpanel</code>, It can loop to generate more same structures.</p>
  
  <p>How can I change background color of texblock when I click it?</p>
  
  <p><strong>UPDATE</strong>: <code>I just want change on xaml file not using C#.</code></p>
  
  <p>Default I has yellow, but when I click a textblock, Its background will change to Blue.</p>
  
  <p><strong>UPDATE 2</strong>: If click A, A will change to blue until I click another.</p>
  
  <p>Detail:</p>
  
  <ol>
  <li><p>I click A<code>(A is yellow)</code>, A will change to be blue ==> A is blue</p></li>
  <li><p>I click B<code>(B is yellow and A is blue)</code>, B will change to be blue and A will change to be yellow.</p></li>
  </ol>
  
  <p><strong>UPDATE 3</strong>: How about this?</p>
  
  <pre><code>&lt;stackpanel&gt;
        &lt;textblock Text="A"&gt;&lt;/textblock&gt;
  &lt;/stackpanel&gt;
  
  &lt;stackpanel&gt;
        &lt;textblock Text="A"&gt;&lt;/textblock&gt;
  &lt;/stackpanel&gt;
  &lt;stackpanel&gt;
        &lt;textblock Text="A"&gt;&lt;/textblock&gt;
  &lt;/stackpanel&gt;
  </code></pre>
  
  <p><strong>The question is same above</strong></p>
  
  <p>Thanks!</p>