title: How to turn off the camera on tab or view change
body: <p>Camera doesn't turn off when change Tab/View</p>
  
  <pre class="lang-js prettyprint-override"><code>render() {
    const { hasCameraPermission } = this.state;
    if (hasCameraPermission === null) {
      return &lt;View&gt;&lt;Button
           onPress={() =&gt; this.showCamera()}
             title="Show Camera"
            /&gt;
           &lt;/View&gt;;
    } else if (hasCameraPermission === false) {
      return &lt;Text&gt;No access to camera&lt;/Text&gt;;
    } else {
      return (
        &lt;View&gt;
          &lt;Camera&gt;
          &lt;/Camera&gt;
        &lt;/View&gt;
      );
    }
  }
  </code></pre>
  
  <p>In the view i have the button that can display the Camera. But once, the camera if turn on. When i change tab (tab nvigation) and come back to the view, i doesn't have the button, but a black screen. it seems the camera is not turn off.</p>
  
  <p>Thank you</p>