title: React Native TextInput setState() issue
body: <p>I am having an issue with React Native's this.setState() within a TextInput's onChangeText. I am trying to display the content of the TextInput in the Text tag below it. However, it displays nothing -- the setState() call never changes this.state.searchtext. I also get no errors. Thank you in advance for your help! Here is my code:</p>
  
  <pre><code> export default class ShowScreen extends Component {
  constructor(props) {
      super(props);
      this.state = {
          searchtext: ""
      };
  }
  render() {
      var thisscreen = (
          &lt;View&gt;
              &lt;ScrollView
                  horizontal={true}
                  showsHorizontalScrollIndicator={false}
                  pagingEnabled={true}
              &gt;
                  &lt;View
                      style={{
                          flex: 1,
                          height: totalheight,
                          justifyContent: "space-around",
                          alignItems: "center",
                          width: totalwidth,
                          backgroundColor: "#FF0000"
                      }}
                  &gt;
                      &lt;TextInput
                          style={{ height: 80, fontSize: 20 }}
                          placeholder="placeholder"
                          value={this.state.searchtext}
                          onChangeText={searchtext =&gt;
                              this.setState({ searchtext })
                          }
                          ref={input =&gt; {
                              this.textInput = input;
                          }}
                          returnKeyType="go"
                      /&gt;
                      &lt;Text&gt;{this.state.searchtext}&lt;/Text&gt;
                  &lt;/View&gt;
              &lt;/ScrollView&gt;
          &lt;/View&gt;
      );
      return thisscreen;
  }
  }
  </code></pre>