title: Get dictionary key by value
body: <p>How do I get a Dictionary key by value in C#?</p>
  <pre><code>Dictionary&lt;string, string&gt; types = new Dictionary&lt;string, string&gt;()
  {
      {&quot;1&quot;, &quot;one&quot;},
      {&quot;2&quot;, &quot;two&quot;},
      {&quot;3&quot;, &quot;three&quot;}
  };
  </code></pre>
  <p>I want something like this:</p>
  <pre><code>getByValueKey(string value);
  </code></pre>
  <p><code>getByValueKey(&quot;one&quot;)</code> must be return <code>&quot;1&quot;</code>.</p>
  <p>What is the best way do this? Maybe HashTable or SortedLists?</p>