如何从c中的文本文件读取多行文件＃

Question

我有一个包含用户记录的文本文件。在文本文件中，一行用户记录存在于三行文本文件中。现在根据我的要求，我必须读取前三行用于一个用户，过程，并插入到数据库和下三行用于第二用户等等..

这里是我已经用于单线从文本文件读出的代码..

 if (System.IO.File.Exists(location) == true) 
     { 
      using (StreamReader reader = new StreamReader(location)) 
      { 
       while ((line = reader.ReadLine()) != null) 
       {  
         line = line.Trim(); 
       } 
     } 
     } 

请帮助我阅读多行，在这种情况下，从文本文件中的3行。

谢谢..

Answer 1

你可以这样做：

if (System.IO.File.Exists(location) == true) 
     { 
      var lines=File.ReadAllLines(location); 
      int usersNumber = lines.Count()/3; 
      for(int i=0; i < usersNumber; i++){ 
       var firstField=lines[i*3]; 
       var secondField=lines[i*3 +1]; 
       var thirdField=lines[i*3 +2]; 
       DoStuffs(firstField,secondField,thirdField); 
      } 
      if(lines.Count() > usersNumber *3) //In case there'd be spare lines left 
       DoSomethingElseFrom(lines, index=(usersNumber*3 +1)); 
     } 

你正在阅读您的文件的所有行，计数有多少用户有（3组），然后为每个组你”重新检索其关联信息，并最终处理与同一用户相关的3个字段的组。

Answer 2

我已经使用了虚拟dource文件与此内容：

line1_1 /*First line*/ 
line1_2 
line1_3 
line2_1 /*second line*/ 
line2_2 
line2_3 
line3_1 /*third line*/ 
line3_2 
line3_3 
line4_1 /*fourth line*/ 
line4_2 
line4_3 

string result = String.Empty; 
string location = @"c:\users\asdsad\desktop\lines.txt"; 
if (System.IO.File.Exists(location) == true) 
    { 
     using (StreamReader reader = new StreamReader(location)) 
     { 
      string line = String.Empty; 
      while ((line = reader.ReadLine()) != null) /*line has the first line in it*/ 
      { 
       for(int i = 0; i<2; i++) /*only iterate to 2 because we need only the next 2 lines*/ 
        line += reader.ReadLine(); /*use StringBuilder if you like*/ 
       result += line; 
      } 
    } 
    result.Dump(); /*LinqPad Only*/ 

Answer 3

void Main() 
{ 
    var location = @"D:\text.txt"; 
    if (System.IO.File.Exists(location) == true) 
    { 
     using (StreamReader reader = new StreamReader(location)) 
     { 
      const int linesToRead = 3; 
      while(!reader.EndOfStream) 
      { 
       string[] currReadLines = new string[linesToRead]; 
       for (var i = 0; i < linesToRead; i++) 
       { 
        var currLine = reader.ReadLine(); 
        if (currLine == null) 
         break; 

        currReadLines[i] = currLine; 
       } 

       //Do your work with the three lines here 
       //Note; Partial records will be persisted 
       //var userName = currReadLines[0] ... etc... 
      } 
     } 
    } 
}