將信息附加到文本文件

Question

我有一個網站，通過該網站我將記錄添加到數據庫中，並將信息也寫到網站的日志文件中。 信息被很好地寫到文件中...我唯一的問題是如何在每次輸入到數據庫時添加信息。 由於目前是這樣，信息已放入lof文件中，但是隨着每個新插入到數據庫中，日志文件中的現有記錄似乎都被覆蓋，並被新插入替換，因此，總是只向其中添加一個記錄。日志文件。 建議也許……這是我在btnClick事件中使用的代碼。

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?";
    }
}

親切的問候

Answer 1

更改整個代碼塊：

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();

對於這一行：

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

請注意，我現在將NewLine手動NewLine到每行。

Answer 2

閱讀本文： 如何：寫入文本文件（C＃編程指南）

其中，示例＃4顯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:\Users\Public\TestFolder\WriteLines2.txt", true))
{
  file.WriteLine("Fourth line");
}

因此，您可以使用您的代碼執行此操作，它應該可以正常工作：

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

編輯：只需使用陰影向導的答案，它更干凈...