title: Cannot update the value in Text input
body: <p>I cannot update the existing value in text input.</p>
  
  <pre><code>&lt;TextField
                label='Email Id'
                //placeholder={value_email}
                onChangeText={(email) =&gt; this.setState({ email })}
                value={value_email}
              /&gt;
  </code></pre>
  
  <p>here value_email is </p>
  
  <pre><code>const value_email = this.state.userInfo.email;
  </code></pre>
  
  <p>Thanks.</p>