我正在按如下方式访问值对象：accounts [accountNum]
我想对该对象进行一些较小的操作，即：将其增加某种程度，等等。与其输入“ accounts [accountNum] + = something”，不如这样做：
MemberData account = accounts[accountNum];
account.balance += something;
即：“帐户”应该是直接的指针，引用或以某种方式“等同于”键入“ accounts [accountNum]”。但是由于这是一个值类型而不是引用类型，所以它会创建一个副本，而我无法直接操作该对象。
我对“ ref”的所有研究似乎都在谈论在方法参数和返回类型中而不是在变量中使用它。有没有一种简单的方法可以在仍然引用同一对象的情况下，将一个长变量名快捷方式快捷化？
更新：
完整的源代码-请具体参见第46和51行
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
/* * Description of the project:
* To implement an ATM machine which accepts deposits, withdrawals
* DEPOSIT / WITHDRAWAL:
* Account, Amount, Timestamp, TransactionID, Location
* Keep record of all accounts in TXT file, which is updated after each transaction. Of course in live system DB would be used.
* Keep another file that logs all transactions. Make it possible to LINQ the log associated with account, to show transaction history.
* TXT Accounts in form of:
* Account #, Name, Balance
* */
namespace ATMProject
{
class Program
{
static void Main(string[] args)
{
// Globals.DisplayAccounts();
// Deposit.MakeDeposit(1000009, 500, "sydney");
}
}
static class Deposit
{
//TODO Deposit: * Account #, Amount, Timestamp, TransactionID, Location
public static void MakeDeposit(long accountNum, long amount, string location)
{
string timestamp;
string transactionID;
timestamp = DateTime.Now.ToString("yyyyMMddhhmm");
transactionID = Globals.GenerateValidTransactionID();
using (StreamWriter sr = new StreamWriter(Globals.transactions, true))
{
string transactString = $"DEPOSIT| {accountNum}| {amount}| {timestamp}| {transactionID}| {location}";
sr.WriteLine(transactString);
}
Globals.WriteTransactionID(transactionID);
Dictionary<long, MemberData> accounts = Globals.GenerateAccounts();
try
{
//WORKS
MemberData account = accounts[accountNum];
account.balance += amount;
accounts[accountNum] = account;
//DOESN'T BUILD
//ref MemberData account = ref accounts[accountNum];
}
catch (KeyNotFoundException)
{
Console.WriteLine("Deposit failed, selected account number does not exist in accounts.txt");
}
}
}
static class Withdraw
{
}
static class CreateAccount
{
public static void Create(string name, long StartDeposit)
{
long accountNumber;
using (StreamReader sr = new StreamReader(Globals.accountIter))
{
accountNumber = Convert.ToInt64(sr.ReadLine());
sr.Close();
}
using (StreamWriter sr = new StreamWriter(Globals.accounts, true))
{
string accountAdd = $"{accountNumber}| {name}| {StartDeposit}";
sr.WriteLine(accountAdd);
Globals.SetNextAccountNumber();
Console.WriteLine("Successfully created account #" + accountNumber);
sr.Close();
}
}
}
struct MemberData
{
public long accountNum;
public string name;
public long balance;
public MemberData(long accountNum, string name, long balance)
{
this.accountNum = accountNum;
this.name = name;
this.balance = balance;
}
public override string ToString()
{
string thisStr = $"Account #: {accountNum}, Name: {name}, Balance: {balance}";
return thisStr;
}
}
static class Globals
{
public static string basepath = "C:\\Users\\root\\RiderProjects\\ConsoleApp1\\ATMProject\\";
public static string accounts = basepath + "accounts.txt"; //path to all accounts
public static string transactions = basepath + "transactions.txt"; //path to all accounts
public static string accountIter = basepath + "accountIter.txt"; //path to the current account iter
public static string transactIter = basepath + "transactIter.txt"; //path to the current account iter
//class values
public static long GetNextAccountNumber() //returns the next available account #
{
try
{
using (StreamReader sr = new StreamReader(accountIter))
{
long currAccountIter = Convert.ToInt64(sr.ReadLine());
sr.Close();
return currAccountIter;
}
}
catch (IOException e)
{
Console.WriteLine(e.Message);
return -1;
}
}
public static void SetNextAccountNumber() //increments the account #
{
long currAccountIter = GetNextAccountNumber();
if (currAccountIter == -1)
{
Console.WriteLine("Could not SetNextAccountNumber");
return;
}
using (StreamWriter sr = new StreamWriter(accountIter, false))
{
currAccountIter += 1;
sr.WriteLine(currAccountIter);
sr.Close();
}
}
public static Dictionary<long, MemberData> GenerateAccounts() //Returns Dictionary in form of <Account Number, MemberData>
{
Dictionary<long, MemberData> memberList = new Dictionary<long, MemberData>();
using (StreamReader sr = new StreamReader(accounts))
{
while (!sr.EndOfStream)
{
var memberSplit = sr.ReadLine().Split("| ", StringSplitOptions.RemoveEmptyEntries);
long accountNum = Convert.ToInt64(memberSplit[0]);
string name = memberSplit[1];
long balance = Convert.ToInt64(memberSplit[2]);
MemberData member = new MemberData(accountNum, name, balance);
memberList.Add(accountNum, member);
}
}
return memberList;
}
public static void DisplayAccounts()
{
Console.WriteLine("List of all Accounts:\n===========");
foreach (var member in GenerateAccounts())
{
Console.WriteLine(member.Value);
}
}
public static string GetTimestamp()
{
string timestamp = DateTime.Now.ToString("yyyyMMddhhmmss");
return timestamp;
}
private static string GetTransactionIter()
{
using (StreamReader sr = new StreamReader(transactIter))
{
string transactionID = sr.ReadLine();
sr.Close();
return transactionID;
}
}
public static string GenerateValidTransactionID()
{
string IDPart;
string timestamp = GetTimestamp();
string transactionID = GetTransactionIter();
string numberSlice = transactionID.Substring(14);
string timestampSlice = transactionID.Substring(0, 14);
if (timestamp == timestampSlice)
{
IDPart = Convert.ToString(Convert.ToInt64(numberSlice) + 1);
transactionID = timestamp + IDPart;
}
else
{
transactionID = timestamp + 0;
}
return transactionID;
}
public static void WriteTransactionID(string transactionID) //overwrite and write current transactionID to iter
{
using (StreamWriter sr = new StreamWriter(transactIter, false))
{
sr.WriteLine(transactionID);
sr.Close();
}
}
public static void GenereateAndWriteTransactionID()
{
WriteTransactionID(GenerateValidTransactionID());
}
}
}
从C＃7开始，您可以使用局部引用变量：
ref int niceName = ref localVariable.Values.SubArray.Here;
niceName += 20;
请注意，您不能在async方法中使用此方法。它既不适用于属性，也不适用于索引器（数组除外）。