C#如何读取用户输入并将其添加到文本文件中？

我正在尝试制作一个C#应用程序，从.txt文件中读取和输出信息，然后允许用户在该文件末尾输入更多信息。我正在尝试以CSV格式编写文本文件，但在确定如何添加到文件底部时遇到了很多困难。似乎当我尝试时，它会覆盖文件的顶行。感谢您的帮助。这是到目前为止的代码，很抱歉出现了令人困惑的行-我一直在尝试许多不同的东西，我可以在网上找到，试图让它工作

class Program
{
    static void Main(string[] args)
    {
        string UIName = "";
        string UIInvoice = "";
        string UIDue = "";
        string UIAmount = "";

        using (FileStream fs = new FileStream(@"C:\Accounts.txt", FileMode.Open))
        using (StreamReader sr = new StreamReader(fs))
        {
            string content = sr.ReadToEnd();
            string[] lines = content.Split(new string[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries);

            int lineCount = 0;
            List<Account> accounts = new List<Account>();
            foreach (string line in lines)
            {
                string[] column = line.Split(',');
                if (lineCount != 0)
                {
                    Account account = new Account();
                    account.AccountName = column[0];
                    account.InvoiceDate = column[1];
                    account.DueDate = column[2];
                    account.AmountDue = column[3];
                    accounts.Add(account);
                }
                lineCount++;
            }
            Console.WriteLine(content);
        }
        using (FileStream fs = new FileStream(@"C:\Accounts.txt", FileMode.OpenOrCreate))
        using (StreamWriter sw = new StreamWriter(fs))
        {
            Account account = new Account();
            account.AccountName = UIName;
            account.InvoiceDate = UIInvoice;
            account.DueDate = UIDue;
            account.AmountDue = UIAmount;
            //accounts.Add(account);
            string fullText = (UIName + "," + UIInvoice + "," + UIDue + "," + UIAmount);
                    Console.WriteLine("Would you like to enter additional data?");


            Console.WriteLine("Please enter the Account Name: ");
            UIName = Console.ReadLine();
            Console.WriteLine("Please enter the Invoice Date: ");
            UIInvoice = Console.ReadLine();
            Console.WriteLine("Please enter the Due Date: ");
            UIDue = Console.ReadLine();
            Console.WriteLine("Please enter the AmountDue: ");
            UIAmount = Console.ReadLine();

            File.AppendAllText("C:/Accounts.txt", fullText + Environment.NewLine);//can't get this way working, even after switching "\"s to "/"s. It says that the file is being used by another process.

            Console.ReadLine();
        }
    }
}
}

txt文件显示：

Account Name,Invoice Date,Due Date,Amount Due
Jane Doe,1/12/2017,2/12/2017,2000.00
Gonuts Inc,12/31/2017,2/28/2017,1566.50

---

您的代码有两个问题

您必须以append模式@ref chetan comment打开文件

在读取用户输入之前，您正在创建全文字符串，因为它会将空字符串写入文本文件 请在下面找到工作程序类文件

 class Program
{
    static void Main(string[] args)
    {
        string UIName = "";
        string UIInvoice = "";
        string UIDue = "";
        string UIAmount = "";

        using (FileStream fs = new FileStream(@"C:/Accounts.txt", FileMode.Open))
        using (StreamReader sr = new StreamReader(fs))
        {
            string content = sr.ReadToEnd();
            string[] lines = content.Split(new string[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries);

            int lineCount = 0;
            List<Account> accounts = new List<Account>();
            foreach (string line in lines)
            {
                string[] column = line.Split(',');
                if (lineCount != 0)
                {
                    Account account = new Account();
                    account.AccountName = column[0];
                    account.InvoiceDate = column[1];
                    account.DueDate = column[2];
                    account.AmountDue = column[3];
                    accounts.Add(account);
                }
                lineCount++;
            }
            Console.WriteLine(content);
        }
        using (FileStream fs = new FileStream(@"C:/Accounts.txt", FileMode.Append))
        using (StreamWriter sw = new StreamWriter(fs))
        {
            Account account = new Account();
            account.AccountName = UIName;
            account.InvoiceDate = UIInvoice;
            account.DueDate = UIDue;
            account.AmountDue = UIAmount;
            //accounts.Add(account);
            Console.WriteLine("Would you like to enter additional data?");


            Console.WriteLine("Please enter the Account Name: ");
            UIName = Console.ReadLine();
            Console.WriteLine("Please enter the Invoice Date: ");
            UIInvoice = Console.ReadLine();
            Console.WriteLine("Please enter the Due Date: ");
            UIDue = Console.ReadLine();
            Console.WriteLine("Please enter the AmountDue: ");
            UIAmount = Console.ReadLine();
            string fullText = (UIName + "," + UIInvoice + "," + UIDue + "," + UIAmount);
            File.AppendAllText("C:/Accounts.txt", fullText + Environment.NewLine);//can't get this way working, even after switching "\"s to "/"s. It says that the file is being used by another process.
            Console.ReadLine();
        }
    }
}

类程序
{
静态void Main（字符串[]参数）
{
字符串UIName=“”；
字符串UIInvoice=“”；
字符串UIDue=“”；
字符串UIAmount=“”；
使用（FileStream fs=newfilestream（@“C:/Accounts.txt”，FileMode.Open））
使用（StreamReader sr=新StreamReader（fs））
{
字符串内容=sr.ReadToEnd（）；
string[]lines=content.Split（新字符串[]{Environment.NewLine}，StringSplitOptions.RemoveEmptyEntries）；
int lineCount=0；
列表帐户=新列表（）；
foreach（行中的字符串行）
{
string[]column=line.Split（'，'）；
如果（行数！=0）
{
账户=新账户（）；
account.AccountName=列[0]；
account.InvoiceDate=第[1]列；
account.DueDate=列[2]；
account.AmountDue=第[3]列；
账户。添加（账户）；
}
lineCount++；
}
Console.WriteLine（内容）；
}
使用（FileStream fs=newfilestream（@“C:/Accounts.txt”，FileMode.Append））
使用（StreamWriter sw=新StreamWriter（fs））
{
账户=新账户（）；
account.AccountName=UIName；
account.InvoiceDate=ui发票；
account.DueDate=ui到期日；
account.AmountDue=ui金额；
//账户。添加（账户）；
WriteLine（“是否要输入其他数据？”）；
Console.WriteLine（“请输入帐户名：”）；
UIName=Console.ReadLine（）；
Console.WriteLine（“请输入发票日期：”）；
UIInvoice=Console.ReadLine（）；
Console.WriteLine（“请输入到期日期：”）；
UIDue=Console.ReadLine（）；
Console.WriteLine（“请输入到期金额：”）；
UIAmount=Console.ReadLine（）；
字符串全文=（UIName+”、“+UIInvoice+”、“+UIDue+”、“+UIAmount”）；
File.AppendAllText（“C:/Accounts.txt”，fullText+Environment.NewLine）；//即使在将“\”s切换到“/”s之后，也无法以这种方式工作。它表示该文件正被另一个进程使用。
Console.ReadLine（）；
}
}
}

您的代码存在多个问题

您希望将数据附加到文件的末尾，但您正在使用

OpenOrCreate

模式打开

FileStream

<代码>打开或创建模式将文件指针放在文件的开头。因此，在这之后，无论您向文件写入什么，它都将覆盖文件的现有内容

您正在打开

FileStream

和

StreamWriter

，但不使用它们将内容写入文件。您应该使用

sw.WriteLine（全文）

，而不是

File.AppendAllText

此外，您在代码中的错误位置写入了文件内容

以下是删除了上述所有问题的代码

static void Main(string[] args)
    {
        string UIName = "";
        string UIInvoice = "";
        string UIDue = "";
        string UIAmount = "";
        var filePath = @"D:\Accounts.txt";
        using (FileStream fs = new FileStream(filePath, FileMode.OpenOrCreate))
        {
            using (StreamReader sr = new StreamReader(fs))
            {
                string content = sr.ReadToEnd();
                string[] lines = content.Split(new string[] {Environment.NewLine},
                    StringSplitOptions.RemoveEmptyEntries);

                int lineCount = 0;
                List<Account> accounts = new List<Account>();
                foreach (string line in lines)
                {
                    string[] column = line.Split(',');
                    if (lineCount != 0)
                    {
                        Account account = new Account();
                        account.AccountName = column[0];
                        account.InvoiceDate = column[1];
                        account.DueDate = column[2];
                        account.AmountDue = column[3];
                        accounts.Add(account);
                    }
                    lineCount++;
                }
                Console.WriteLine(content);
            }
        }

        using (FileStream fs = new FileStream(filePath, FileMode.Append))
        {
            using (StreamWriter sw = new StreamWriter(fs))
            {
                Account account = new Account();
                account.AccountName = UIName;
                account.InvoiceDate = UIInvoice;
                account.DueDate = UIDue;
                account.AmountDue = UIAmount;
                //accounts.Add(account);

                Console.WriteLine("Would you like to enter additional data?");
                Console.WriteLine("Please enter the Account Name: ");
                UIName = Console.ReadLine();
                Console.WriteLine("Please enter the Invoice Date: ");
                UIInvoice = Console.ReadLine();
                Console.WriteLine("Please enter the Due Date: ");
                UIDue = Console.ReadLine();
                Console.WriteLine("Please enter the AmountDue: ");
                UIAmount = Console.ReadLine();

                string fullText = (UIName + "," + UIInvoice + "," + UIDue + "," + UIAmount);

                sw.WriteLine(fullText);

                Console.ReadLine();
            }
        }
    }

static void Main（字符串[]args）
{
字符串UIName=“”；
字符串UIInvoice=“”；
字符串UIDue=“”；
字符串UIAmount=“”；
var filePath=@“D:\Accounts.txt”；
使用（FileStream fs=newfilestream（filePath，FileMode.OpenOrCreate））
{
使用（StreamReader sr=新StreamReader（fs））
{
字符串内容=sr.ReadToEnd（）；
string[]lines=content.Split（新字符串[]{Environment.NewLine}，
StringSplitOptions.RemoveEmptyEntries）；
int lineCount=0；
列表帐户=新列表（）；
foreach（行中的字符串行）
{
string[]column=line.Split（'，'）；
如果（行数！=0）
{
账户=新账户（）；
account.AccountName=列[0]；
account.InvoiceDate=第[1]列；
account.DueDate=列[2]；
account.AmountDue=第[3]列；
账户。添加（账户）；
}
lineCount++；
}
Console.WriteLine（内容）；
}
}
使用（FileStream fs=newfilestream（filePath，FileMode.Append））
{
使用（StreamWriter sw=新StreamWriter（fs））
{
账户=新账户（）；
account.AccountName=UIName；
account.InvoiceDate=ui发票；
account.DueDate=ui到期日；
account.AmountDue=ui金额；
//账户。添加（账户）；
WriteLine（“是否要输入其他数据？”）；
Console.WriteLine（“请输入帐户名：”）；
UIName=Console.ReadLine（）；
控制台。WriteLine（“请输入发票
static void Main(string[] args)
    {
        string UIName = "";
        string UIInvoice = "";
        string UIDue = "";
        string UIAmount = "";
        var filePath = @"D:\Accounts.txt";
        using (FileStream fs = new FileStream(filePath, FileMode.OpenOrCreate))
        {
            using (StreamReader sr = new StreamReader(fs))
            {
                string content = sr.ReadToEnd();
                string[] lines = content.Split(new string[] {Environment.NewLine},
                    StringSplitOptions.RemoveEmptyEntries);

                int lineCount = 0;
                List<Account> accounts = new List<Account>();
                foreach (string line in lines)
                {
                    string[] column = line.Split(',');
                    if (lineCount != 0)
                    {
                        Account account = new Account();
                        account.AccountName = column[0];
                        account.InvoiceDate = column[1];
                        account.DueDate = column[2];
                        account.AmountDue = column[3];
                        accounts.Add(account);
                    }
                    lineCount++;
                }
                Console.WriteLine(content);
            }
        }

        using (FileStream fs = new FileStream(filePath, FileMode.Append))
        {
            using (StreamWriter sw = new StreamWriter(fs))
            {
                Account account = new Account();
                account.AccountName = UIName;
                account.InvoiceDate = UIInvoice;
                account.DueDate = UIDue;
                account.AmountDue = UIAmount;
                //accounts.Add(account);

                Console.WriteLine("Would you like to enter additional data?");
                Console.WriteLine("Please enter the Account Name: ");
                UIName = Console.ReadLine();
                Console.WriteLine("Please enter the Invoice Date: ");
                UIInvoice = Console.ReadLine();
                Console.WriteLine("Please enter the Due Date: ");
                UIDue = Console.ReadLine();
                Console.WriteLine("Please enter the AmountDue: ");
                UIAmount = Console.ReadLine();

                string fullText = (UIName + "," + UIInvoice + "," + UIDue + "," + UIAmount);

                sw.WriteLine(fullText);

                Console.ReadLine();
            }
        }
    }