Question

我有一个文本文件（比如text1.txt），其中包含以下几行：

4410 Rel testRel1
4411 Dbg testDbg1
4412 Dbg testDbg2
4412 Rel testRel2
4413 Rel testRel3
4413 Dbg testDbg3
4414 Rel testRel4
4415 Rel testRel5

现在，我想将所有带有“Rel”字样的行写入文本文件（比如text2.txt）。所以我的text2.txt应该是这样的：

4410 Rel testRel1
4412 Rel testRel2
4413 Rel testRel3
4414 Rel testRel4
4415 Rel testRel5

Atlast，我的代码应该读取text2.txt返回text2.txt的最后一行的前四个字符（即4415），将text1.txt的路径作为输入。以下是我的代码。可能是我写了一半而且不知道c＃。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Activities;
using Microsoft.Build.Utilities;
using Microsoft.Build.Framework;
using System.IO;
using Microsoft.TeamFoundation.Build.Client;

namespace Build_Tasks.Activities
{
    [BuildActivity(HostEnvironmentOption.All)]
    public sealed class GetBuildNumber : CodeActivity
    {
        // Define an activity input argument of type string
        public InArgument<string> TextFileName { get; set; }
        public OutArgument<string> setBuildNumber { get; set; }
        private string temp_FilePath = "c:\\temp.txt";

        // If your activity returns a value, derive from CodeActivity<TResult>
        // and return the value from the Execute method.
        protected override void Execute(CodeActivityContext context)
        {
            // Obtain the runtime value of the Text input argument
            string TextFileName = context.GetValue(this.TextFileName);
            string TextFilePath = TextFileName;
            string[] Lines = File.ReadAllLines(TextFilePath);
            //string wordrel = "Rel";
            System.IO.StreamReader file = new System.IO.StreamReader(TextFilePath);
            List<string> Spec = new List<string>();
            string line;
            System.IO.StreamWriter file2 = new System.IO.StreamWriter(temp_FilePath);
            while ((line = file.ReadLine()) != null)
            {
                if(line.Contains("Rel"))
                     {
                        file2.WriteLine(line);
                      }
            }
            var lastline = File.ReadLines(temp_FilePath).Last();
            string number = lastline.Substring(0, 4);
            context.SetValue<string>(this.setBuildNumber, number);
            }
    }
    }

Answer 1

试试这个......

    static void Main(string[] args)
    {
        int counter = 0;
        string line;

        // Read the file(your SXA file) and display it line by line.
        System.IO.StreamReader file = new System.IO.StreamReader("c:\\SXA63.txt");
        while((line = file.ReadLine()) != null)
         {         //File to write lines which contain Rel. 
                   using(StreamWriter writer = new StreamWriter("c:\\Relfile.txt",true))
                    {
                       if(line.Contains("Rel"))
                      writer.WriteLine(line);
                    }
            counter++;

        }
        String last = File.ReadLines(@"C:\Relfile.txt").Last();
        string buildNo = last.Substring(0, 4);
        file.Close();
        Console.ReadKey();

    }
}

Answer 2

如果您只需要file2获取内部版本号，则根本不必创建它：

protected override void Execute(CodeActivityContext context)
{
    // Obtain the runtime value of the Text input argument
    string TextFileName = context.GetValue(this.TextFileName);
    string TextFilePath = TextFileName;

    string number = null;
    var splitChars = new[]{ ' ' };

    foreach (var line in File.ReadLines(TextFilePath))
    {
        var values = line.Split(splitChars, StringSplitOptions.RemoveEmptyEntries).ToArray();
        if (values.Length < 3)
            continue;

        buildNumber = (values[1] == "Rel" ? values[0] : buildNumber);
    }

    context.SetValue<string>(this.setBuildNumber, number);        
}

由于您只对 last 内部版本号感兴趣，因此可以通过不从头开始读取文件，然后搜索流到最后并跳回直到找到该行来进一步优化与Rel。

Answer 3

这将迭代原始文件的行并将相关行复制到新文件：

string tempFile = "text2.txt";
List<string> linesWithREL = new List<string>();
using (var sr = new StreamReader("file.txt"))
using (var sw = new StreamWriter(tempFile))
{
    string line;

    while ((line = sr.ReadLine()) != null)
    {
        //check if the current line should be copied
        if (line.Contains("whatever"))
        {
               linesWithREL.Add(line.Substring(0,4));
               sw.WriteLine(line);
        }
    }
}

Answer 4

试试这个：

string path1 = @"C:\data1.txt";
string path2 = @"C:\data2.txt";
string searchKey = "Rel";
List<string> newlines = new List<string>();
foreach (var line in File.ReadLines(path1))
{
if (line.Split(new char[]{' '},
         StringSplitOptions.RemoveEmptyEntries)[1].Contains(searchKey))
{
newlines.Add(line);
}
}
File.WriteAllLines(path2,newlines.ToArray());

Answer 5

好的，所以当我读到一些评论时，你的问题不是读/写，而是在这一行：

var lastline = File.ReadLines(temp_FilePath).Last();

在对同一文件使用File.ReadLine之前，您必须先关闭作者。

file2.Flush();
file2.Close();
var lastline = File.ReadLines(temp_FilePath).Last();

如果您想优化代码，可以添加一些答案，无需复制。

如何读取行中特定单词的文本文件并将整行写入另一个文本文件？

5 个答案: