刚刚启动项目，很糟糕

代码：

import React, {Component} from 'react';
import { Text, View } from 'react-native';
export default class SignUp extends Component() {
    constructor(props){
        super(props);
    }
    render() {
        return (
            <View>
                <Text>SignUp</Text>
            </View>
        );
    }
}

堆栈导航器：

import { createStackNavigator } from "react-navigation";
import SignUp from "../screens/SignUpScreen";

export default AuthStackNavigator = createStackNavigator({
    SignUp: SignUp,
})

出现此错误：

错误图片