在文本文件中的特定位置添加新行。

时间:2013-04-25 10:16:52

标签: c# io streamwriter

我正在尝试在文件中添加特定的文本行。特别是在两个边界之间。

如果我想在item1的边界之间添加一行,它会是什么样子:

[item1]
2550 coins 995 200000 7
2550 coins 995 200000 7
2550 coins 995 200000 7
2550 coins 995 200000 7
2550 coins 995 200000 7
//Add a line here in between the specific boundaries
[/item1]
[item2]
2550 coins 995 200000 7
2550 coins 995 200000 7
2550 coins 995 200000 8
2550 coins 995 200000 7
2550 coins 995 200000 7
[/item2]
[item3]
2550 coins 995 200000 7
2550 coins 995 200000 7
2550 coins 995 200000 7
2550 coins 995 200000 7
2550 coins 995 200000 7
[/item3]

这是我到目前为止所尝试过的,但它远远不够正确。它一直说文件正由读者使用,所以它不能由作者编辑,当我确实让它工作时它清除了整个文件。

public void createEntry(String npcName)
{
    String line;
    String fileName = "Drops.de";
    StreamWriter streamWriter = new StreamWriter(fileName);
    StreamReader streamReader = new StreamReader(fileName);
    line = streamReader.ReadLine();
    if (line == ("[" + npcName + "]"))
    {
        streamReader.ReadLine();
        streamWriter.WriteLine("Test");
    }
}

我还想知道如何在文档末尾写行。

3 个答案:

答案 0 :(得分:15)

这将添加您想要的行。 (确保添加了using System.IO;

public void CreateEntry(string npcName) //npcName = "item1"
{
    var fileName = "test.txt";
    var endTag = String.Format("[/{0}]", npcName);
    var lineToAdd = "//Add a line here in between the specific boundaries";

    var txtLines = File.ReadAllLines(fileName).ToList();   //Fill a list with the lines from the txt file.
    txtLines.Insert(txtLines.IndexOf(endTag), lineToAdd);  //Insert the line you want to add last under the tag 'item1'.
    File.WriteAllLines(fileName, txtLines);                //Add the lines including the new one.
}

答案 1 :(得分:2)

您不应该打开文件两次,请尝试:

FileStream fileStream = new FileStream(fileName, FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.None);
StreamWriter streamWriter = new StreamWriter(fileStream);
StreamReader streamReader = new StreamReader(fileStream);

另一个想法是插入行的逻辑,也许更简单的方法是逐行将数据复制到新文件中,在需要时插入新部分并继续。或者在记忆中做。

要在最后添加行,您可以使用FileMode.Append或执行您自己的搜索

答案 2 :(得分:0)

尝试这种方法

using System.IO;
using System.Linq;

    /// <summary>
    /// Add a new line at a specific position in a simple file        
    /// </summary>
    /// <param name="fileName">Complete file path</param>
    /// <param name="lineToSearch">Line to search in the file (first occurrence)</param>
    /// <param name="lineToAdd">Line to be added</param>
    /// <param name="aboveBelow">insert above(false) or below(true) of the search line. Default: above </param>
    internal static void insertLineToSimpleFile(string fileName, string lineToSearch, string lineToAdd, bool aboveBelow = false)
    {          
        var txtLines = File.ReadAllLines(fileName).ToList();
        int index = aboveBelow?txtLines.IndexOf(lineToSearch)+1: txtLines.IndexOf(lineToSearch);
        if (index > 0)
        {
            txtLines.Insert(index, lineToAdd);
            File.WriteAllLines(fileName, txtLines);
        }
    }