飞镖Flutter:如何在另一个类中调用一个类方法 [英] Dart & Flutter: How to call for a class method inside another class

问题描述

这里是Dart的新手，如果这是一个多余的问题，请提前抱歉；我找不到答案.我创建了一个函数 simulateRequest ，然后将其传递给自己的类 SimReq ，并将其单独保存在文件中.我将类导入了主文件，但是当我尝试执行该类时，出现错误，这是类代码:

new to Dart here, sorry in advance if this is a redundant question; I couldn't find the answer. I created a function simulateRequest and then passed it to its own class SimReq and saved it in a file on its own. I imported the class in the main file, but when I try to execute it, I get an error, here is the class code:

class SimReq {
  void simulateRequest() async {

    // first future holds family name
    String famNameFunc = await Future.delayed(Duration(seconds: 2), (){
      String famName = 'Shanshi';
      return famName;
    });


    // second future holds first name
    String compName = await Future.delayed(Duration(seconds: 1), (){
      String fstName = 'Yoshi';
      String compName = '$fstName - $famNameFunc';
      return compName;
    });

    print(compName);
  }
    SimReq(){
    simulateRequest();
 }
}

这是主要的文件代码:

import 'package:flutter/material.dart';
import 'package:wtap/pages/simreq.dart';

class ChoseLocation extends StatefulWidget {
  @override
  _ChoseLocationState createState() => _ChoseLocationState();
}

class _ChoseLocationState extends State<ChoseLocation> {
  int counter = 0;
  @override
  void initState() {
    super.initState();
    print('This is the initial state.');
    SimReq.simulateRequest(); // I am trying to execute the function here.
  }
  

推荐答案

如果要访问SimReq类的方法，则必须实例化该对象，例如:

You have to instantiate an object of the SimReq class if you want access to its methods like:

SimReq simReq = SimReq();
simReq.simulateRequest();

或使用 static 关键字使该函数在此类之外可访问

or use the static keyword to make this function accessible outside of this class

static void simulateRequest() async {

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