我有一个文本文件,其中包含约100000篇文章。文件的结构是:
文件ID 42944-YEAR:5日期03 \ 08 \ 11.Cat政治文章内容1文件ID 42945-YEAR:5日期03 \ 08 \ 11.Cat政治文章内容2
我想用C#打开此文件以逐行处理它。我尝试了这段代码:
String[] FileLines = File.ReadAllText(
TB_SourceFile.Text).Split(Environment.NewLine.ToCharArray());
但它说:
类型异常“ System.OutOfMemoryException”原为抛出。
问题是如何打开此文件并逐行读取。
您可以打开文件并read it as a stream,而不是一次将所有内容都加载到内存中。
从MSDN:
using System;
using System.IO;
class Test
{
public static void Main()
{
try
{
// Create an instance of StreamReader to read from a file.
// The using statement also closes the StreamReader.
using (StreamReader sr = new StreamReader("TestFile.txt"))
{
String line;
// Read and display lines from the file until the end of
// the file is reached.
while ((line = sr.ReadLine()) != null)
{
Console.WriteLine(line);
}
}
}
catch (Exception e)
{
// Let the user know what went wrong.
Console.WriteLine("The file could not be read:");
Console.WriteLine(e.Message);
}
}
}
您的文件太大,无法像File.ReadAllText
那样一口气读入内存。您应该逐行阅读文件。
改编自MSDN:
string line;
// Read the file and display it line by line.
using (StreamReader file = new StreamReader(@"c:\yourfile.txt"))
{
while ((line = file.ReadLine()) != null)
{
Console.WriteLine(line);
// do your processing on each line here
}
}
以这种方式,在任何时候内存中最多只有一行文件。
如果使用的是.NET Framework 4,则System.IO.File上有一个新的静态方法,称为ReadLines,该方法返回IEnumerable字符串。我相信它已添加到此确切方案的框架中;但是,我尚未亲自使用它。
MSDN Documentation - File.ReadLines Method (String)
Related Stack Overflow Question - Bug in the File.ReadLines(..) method of the .net framework 4.0
类似这样的东西:
using (var fileStream = File.OpenText(@"path to file"))
{
do
{
var fileLine = fileStream.ReadLine();
// process fileLine here
} while (!fileStream.EndOfStream);
}