content: import React from 'react';
  import { NavLink } from 'react-router-dom';
  
  import darkBaseTheme from 'material-ui/styles/baseThemes/darkBaseTheme';
  import MuiThemeProvider from 'material-ui/styles/MuiThemeProvider';
  import getMuiTheme from 'material-ui/styles/getMuiTheme';
  import AppBar from 'material-ui/AppBar';
  // import RaisedButton from 'material-ui/RaisedButton';
  const Header = () => {
    const activeStyle = {
      padding:3,
      backgroundColor: 'grey',
      border: '2px dashed red',
    };
    const menuStyle = {
      padding:3,
      backgroundColor: 'grey',
      border: '2px dashed red',
    };
    const style = {
      margin: 8,
    };
    const appbarstyle = {
      paddingTop:1,
      paddingLeft:1,
      margin: 1,
    };
  
    return (
      <MuiThemeProvider muiTheme={getMuiTheme(darkBaseTheme)}>
        <div>
          <div className="headStyle">
            <AppBar style={appbarstyle}  title="Sovos Reactivo" />
            <div style={menuStyle}>
            <NavLink exact to="/" >Dashboard</NavLink>
            {' | '}
            <NavLink to="/alumnos" activeStyle={activeStyle}>Alumnos</NavLink>
            {' | '}
            <NavLink to="/materias" activeStyle={activeStyle}>Materias</NavLink>
            {' | '}
            <NavLink to="/profesores" activeStyle={activeStyle}>Profesores</NavLink>
            {' | '}
            <NavLink to="/cursado" activeStyle={activeStyle}>Cursado</NavLink>
            {' | '}
            <NavLink to="/about" activeStyle={activeStyle}>About</NavLink>
            </div>
          </div>
        </div>
      </MuiThemeProvider>
    );
  };
  
  export default Header;
  