问Express 4.15.5不渲染angular 7路由

EN

ng build --watch

var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');

// var index = require('./routes/index');
// var users = require('./routes/users');

var app = express();

// view engine setup
// app.set('views', path.join(__dirname, 'views'));
// app.set('view engine', 'pug');
app.engine('html', require('ejs').renderFile); 
app.set('view engine', 'html');
// uncomment after placing your favicon in /public
//app.use(favicon(path.join(__dirname, 'public', 'favicon.ico')));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));

app.use('abcd',function(req, res, next){
  return res.sendFile(app.get('public') + '/index.html');
});
app.use('/',function(req, res, next){
  return res.sendFile(app.get('public') + '/index.html');
});
// app.use('/', index);
// app.use('/users', users);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  var err = new Error('Not Found');
  err.status = 404;
  next(err);
});

// error handler
app.use(function(err, req, res, next) {
  // set locals, only providing error in development
  res.locals.message = err.message;
  res.locals.error = req.app.get('env') === 'development' ? err : {};

  // render the error page
  res.status(err.status || 500);
  res.render('error' );
});

module.exports = app;

i.e localhost:4200/abcd - works fine

localhost:3000/abcd - it is not working

Error: Failed to lookup view "error" in views directory "E:\ngME\server\views"
at Function.render (E:\ngME\server\node_modules\express\lib\application.js:580:17)
at ServerResponse.render (E:\ngME\server\node_modules\express\lib\response.js:971:7)
at E:\ngME\server\app.js:50:7
at Layer.handle_error (E:\ngME\server\node_modules\express\lib\router\layer.js:71:5)
at trim_prefix (E:\ngME\server\node_modules\express\lib\router\index.js:315:13)
at E:\ngME\server\node_modules\express\lib\router\index.js:284:7
at Function.process_params (E:\ngME\server\node_modules\express\lib\router\index.js:335:12)
at next (E:\ngME\server\node_modules\express\lib\router\index.js:275:10)
at Layer.handle_error (E:\ngME\server\node_modules\express\lib\router\layer.js:67:12)
at trim_prefix (E:\ngME\server\node_modules\express\lib\router\index.js:315:13)