Question

对于我的Web服务课程，我正在尝试创建一个非常简单的登录系统。我有一个问题，每当调用checkCredentials时，createAccounts（）都会持续无限次。知道为什么吗？

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.ServiceModel.Web;
using System.Text;
using System.IO;

public class Service : IService
{
    static String path = @"PATH REMOVED";
    List<Account> accounts = new List<Account>();
    StreamWriter sw = null;

    private void createAccounts()
    {
        String data = File.ReadAllText(path);
        string[] data2 = data.Split(new string[] { Environment.NewLine }, StringSplitOptions.None);
        string[] temp;
        for (int i = 0; i < data2.Length; i++)
        {
            temp = data2[i].Split(',');
            if(!usernameExists(temp[0]) && temp[0] != "")
            {
                accounts.Add(new Account(temp[0],temp[1]));
            }
        }
    }

    public bool CreateAccount(String username, String password)
    {
        createAccounts();
        sw = File.AppendText(path);
        if (!usernameExists(username))
        {
            sw.WriteLine(username + "," + password + "\n");
            sw.Close();
            sw = null;
            return true;
        }
        else
        {
            sw.Close();
            sw = null;
            return false;
        }
    }

    public bool usernameExists(String username)
    {
        createAccounts();
        if(accounts.Exists(a => a.username == username))
            return true;
        else
            return false;
    }

    public bool CheckCredentials(String username, String password)
    {
        createAccounts();
        if (usernameExists(username))
        {
            if(accounts.Find(a => a.username == username).username == username && accounts.Find(a => a.username == username).password == password)
                return true;
            else
                return false;
        }
        else
            return false;

    }

}

class Account
{
    public String username;
    public String password;

    public Account(String u, String p)
    {
        username = u;
        password = p;
    }

}

Answer 1

您将数据保存在文件中，不应无限次写入。当您经常请求时，它会以多线程写入文件，线程会锁定文件。我建议你用try ... catch ...写文件找问题：

    public bool CreateAccount(String username, String password)
    {
        createAccounts();

        try
        {
            sw = File.AppendText(path);
        }
        catch (Exception ex)
        {
            throw ex;
        }
        if (!usernameExists(username))
        {
            sw.WriteLine(username + "," + password + "\n");
            sw.Close();
            sw = null;
            return true;
        }
        else
        {
            sw.Close();
            sw = null;
            return false;
        }
    }

Answer 2

您在createAccounts和usernameExists之间有一个循环。只要data2.Length不为零，你就会无休止地循环。

Web Service中称为无限次的方法

2 个答案: