title: React Native ref/ reference on the Component is not working
body: <p>I am developing a React Native application. What I am doing now in my application is that I am trying to use reference/ ref on my component.</p>
  
  <p>This is my code</p>
  
  <pre><code>class Gallery extends React.Component {
    constructor(props) {
      super(props);
  
    }
  
    _handleDownloadButton = () =&gt; {
      var uri = this.refs.logoImage.props.source;
      var promise = CameraRoll.saveImageWithTag(uri);
      promise.then(function(result) {
        console.log('save succeeded ' + result);
        Alert.alert('Saved')
      }).catch(function(error) {
        console.log('save failed ' + error);
        Alert.alert('Error')
      });
    }
  
    render() {
      return (
        &lt;View&gt;
          &lt;Button
          onPress={() =&gt; {
            this._handleDownloadButton();
          }}
          title="Download photo"&gt;
          &lt;/Button&gt;
          &lt;Image ref="logoImage" style={{ width: 100, height: 100 }} source={{ uri: 'https://static.standard.co.uk/s3fs-public/thumbnails/image/2016/05/22/11/davidbeckham.jpg?w968' }} /&gt;
        &lt;/View&gt;
      );
    }
  }
  
  export default Gallery;
  </code></pre>
  
  <p>When I click on the download button, I got the following error.</p>
  
  <pre><code>Cannot find property source of undefined
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/RcrZu.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/RcrZu.png" alt="enter image description here"></a></p>
  
  <p>I tried this too.</p>
  
  <pre><code>&lt;Image ref={ref =&gt; this.image = ref} style={{ width: 100, height: 100 }} source={{ uri: 'https://static.standard.co.uk/s3fs-public/thumbnails/image/2016/05/22/11/davidbeckham.jpg?w968' }} /&gt;
  </code></pre>
  
  <p>with</p>
  
  <pre><code>var uri = this.image.props.source;
  </code></pre>
  
  <p>I got the same error. I tried this too.</p>
  
  <p>In the constructor I added</p>
  
  <pre><code>this.image = React.createRef();
  </code></pre>
  
  <p>component</p>
  
  <pre><code>&lt;Image ref={this.image} style={{ width: 100, height: 100 }} source={{ uri: 'https://static.standard.co.uk/s3fs-public/thumbnails/image/2016/05/22/11/davidbeckham.jpg?w968' }} /&gt;
  </code></pre>
  
  <p>with</p>
  
  <pre><code>var uri = this.image.props.source;
  </code></pre>