文本文件更新后，请始终阅读最后一行. [英] Always read last line when the text file have updated.

问题描述

using (var fs = new FileStream("C:\\test.txt", FileMode.Open, FileAccess.Read, FileShare.ReadWrite | FileShare.Delete))
            using (var reader = new StreamReader(fs))
            {
                while (true)
                {
                    var line = reader.ReadLine();

                    if (!String.IsNullOrEmpty(line))
                    {                       
                        MessageBox.Show("Line read: " + line);

朋友们，当前代码可以在运行应用程序时读取所有行，但是当文本文件仅被更新/修改时，我希望它读取最后一行吗?需要帮助吗?

---

Loginthiren

Hi friends, current code can read all line when running the application, but I want it to read the last line when ever the text file are updated/modify only? Need help on this please?

---

Loginthiren

推荐答案

你好，

 这是一个使用VS2010/dotNet4/Vista的控制台项目示例；

 Here is a Console Project example using VS2010/dotNet4/Vista;

static void Main( string[] args )
{
	StreamReader sr = new StreamReader( File.OpenRead( "X:\\Temp\\MusicList.txt" ) );

	if ( sr != null )
	{
		int x = 0, y = 0;
		string s1 = "", s2 ="";

		while( !sr.EndOfStream )
		{
			s1 = sr.ReadLine();

			x = s1.Length;

			Console.WriteLine( "{0} : {1} = {2}", y, s1, x );

			y++;
		}

		Console.WriteLine( "\nNumber of Lines  : {0} (Zero based index)", y );
		Console.WriteLine( "Last Line Length : {0}", x );
		Console.WriteLine( "\nEOF = FileLength @ {0}", sr.BaseStream.Position );

		sr.BaseStream.Seek( ( sr.BaseStream.Length - 2 ), SeekOrigin.Begin );

		// If 0x0D0A present, Subtract 2 more, Return/NewLine codes
		if ( sr.Read() == 0x0D && sr.Read() == 0x0A )
		{
			x += 2;
		}

		sr.BaseStream.Seek( (sr.BaseStream.Length - x ), SeekOrigin.Begin );

		Console.WriteLine( "Last Line FPOS   @  {0}", sr.BaseStream.Position );

		s2 = sr.ReadLine();

		if ( s1 == s2 )
		{
			Console.WriteLine( "Match" );
		}
		else
		{
			Console.WriteLine( "FPOS MisMatch" );
		}

	sr.Close();
	}
}

以下是输出结果:

请记住，CR/LF代码在读入对象类型字符串后会被删除.除非另有说明

 Just remember, CR/LF codes, are dropped after the read into object type string. Unless stated

否则在流中.

希望这会有所帮助！ :)

 Hope this helps! :)

这篇关于文本文件更新后，请始终阅读最后一行.的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！