title: TextInput onChangeText not working React Native
body: <p>i am very new to this platform , it my 2nd day on this. i trying to learn it by myself by creating simple login , sign up , news feed application . i am able to build login page but while getting values from InputText , it display me error saying "<strong>Can not specify both value and Children</strong>" , Here i am posting my login.js class</p>
  
  <pre><code>export default class LoginScreen extends Component {
  
      constructor(props) {
          super(props);
          this.state = {
              username: '',
              password: ''
          };
      }
      login = () =&gt; {
          alert(this.state.username + " " + this.state.password);
      }
      render() {
          return (
              &lt;View style={styles.container}&gt;
  
                  &lt;Image source={require('../images/hulk.jpg')} style={styles.backgroundimage}&gt;
                      &lt;View style={styles.content}&gt;
                          &lt;Image source={require('../images/logo.png')} style={styles.logo}&gt;
                          &lt;/Image&gt;
  
                          &lt;View style={styles.inputcontainer}&gt;
  
                              &lt;TextInput underLineColorAndroid='transparent' style={styles.input} value={this.state.username} onChangeText={(username) =&gt; this.setState({ username })} placeholderText='username' &gt; &lt;/TextInput&gt;
  
                              &lt;TextInput secureTextEntry={true} underLineColorAndroid='transparent' style={styles.input} value={this.state.password} onChangeText={(password) =&gt; this.setState({ password })} placeholderText='password' placeholderTextColor='black'&gt; &lt;/TextInput&gt;
  
                          &lt;/View&gt;
                          &lt;TouchableOpacity onPress={this.login} style={styles.buttonContainer}&gt;
                              &lt;Text style={styles.buttonText}&gt;LOGIN&lt;/Text&gt;
                          &lt;/TouchableOpacity&gt;
                      &lt;/View&gt;
                  &lt;/Image&gt;
              &lt;/View&gt;
          );
      }
  }
  </code></pre>
  
  <p>Please let me know where i am going wrong in code</p>
  
  <p>Regards</p>