将信息追加到文本文件

Question

我有一个网站，我正在使用该网站将记录添加到数据库中，并且我还正在写入作为网站一部分的日志文件的信息。信息已写入文件精细...我唯一的问题是如何将每个输入的信息添加到数据库中。目前，信息被放入 lof 文件中，但随着每次新插入到数据库中，日志文件中的现有记录似乎被覆盖并替换为新插入，因此始终只有一条记录添加到日志文件中。建议也许...这是我在btnClick事件中使用的代码。

protected void btnSubmitRating_Click1(object sender, EventArgs e)
{
    int rating = 0;
    try
    {
        if (radRating.Items[0].Selected)
        {
            rating = 1;
        }
        if (radRating.Items[1].Selected)
        {
            rating = 2;
        }
        else if (radRating.Items[2].Selected)
        {
            rating = 3;
        }
        else if (radRating.Items[3].Selected)
        {
            rating = 4;
        }
        else if (radRating.Items[4].Selected)
        {
            rating = 5;
        }
        FileStream rate = new FileStream(Server.MapPath("~/rateBooks.log"), FileMode.Open, FileAccess.ReadWrite);
        BufferedStream bs = new BufferedStream(rate);
        rate.Close();

        StreamWriter sw = new StreamWriter(Server.MapPath("~/rateBooks.log"));
        sw.WriteLine("userName " + txtUserName.Text + " " + "bookTitle " + txtBookTitle.Text + " " + "ISBN " + txtISBN.Text);
        sw.Close();

        Service s = new Service();
        s.bookRatedAdd(txtBookTitle.Text, rating, txtReview.Text, txtISBN.Text, txtUserName.Text);
        btnSubmitRating.Enabled = false;
        radRating.Enabled = false;            
    }
    catch (Exception em)
    {
        lblError.Text = em.Message; 
        //lblError.Text = "This book has already been reviewed by yourself?";
    }
}

亲切问候

Answer 1

更改整个代码块：

FileStream rate = new FileStream(Server.MapPath("~/rateBooks.log"), FileMode.Open, FileAccess.ReadWrite);
BufferedStream bs = new BufferedStream(rate);
rate.Close();
StreamWriter sw = new StreamWriter(Server.MapPath("~/rateBooks.log"));
sw.WriteLine("userName " + txtUserName.Text + " " + "bookTitle " + txtBookTitle.Text + " " + "ISBN " + txtISBN.Text);
sw.Close();

到这一行：

File.AppendAllText(Server.MapPath("~/rateBooks.log"), "userName " + txtUserName.Text + " " + "bookTitle " + txtBookTitle.Text + " " + "ISBN " + txtISBN.Text + Environment.NewLine);

请注意，我现在正在手动添加NewLine到每一行。

Answer 2

阅读以下内容：如何：写入文本文件（C# 编程指南）

其中，示例 #4 显示了如何附加到文件：

// Example #4: Append new text to an existing file
using (System.IO.StreamWriter file = new System.IO.StreamWriter(@"C:UsersPublicTestFolderWriteLines2.txt", true))
{
  file.WriteLine("Fourth line");
}

所以你可以用你的代码来做到这一点，它应该可以工作：

StreamWriter sw = new StreamWriter(Server.MapPath("~/rateBooks.log"), true);
sw.WriteLine("userName " + txtUserName.Text + " " + "bookTitle " + txtBookTitle.Text + " " + "ISBN " + txtISBN.Text);
sw.Close();

编辑：只需使用影子巫师的答案，它就干净得多...