如何在React-Native中进行API登录身份验证

Question

我不确定如何使用电子邮件和密码进行基本的api登录身份验证。我被困在这里。如果有人可以帮助。那是我的代码：

class LoginScreen extends Component {

  constructor(){
           super();
           this.state = {
            email: '',
            password: '',
            result: false,
           }
       }

    _userLogin() {
         var email = this.state.username;
         var password = this.state.password;
         if (email && password) { // if validation fails, value will be null
           fetch("https://URL/api/login", {
             method: "POST",
             headers: {
               'Accept': 'application/json',
               'Content-Type': 'application/json'
             },
             body: JSON.stringify({
               username: email,
               password: password,
             })
           })
           .then((response) => response.json())
           .then((responseData) => {
             console.log(responseData);
             AlertIOS.alert(
               "Login Success!"
             ),
             this._onValueChange(STORAGE_KEY, responseData.id_token)
           })
           .done();
           renderResults();
         }
       }

       handleEmail = (text) => {
             this.setState({ email: text })
       }

       handlePassword = (text) => {
             this.setState({ password: text })
       }

，然后在输入字段和按钮中使用它。