我想直接写入文件系统，而不是每一行写入字符串，因为这更耗时。
我这样试试：
static void Main(string[] args)
{
string path = @"C:\BankNumber";
var bans = BankAcoutNumbers.BANS;
const int MAX_FILES = 80;
const int BANS_PER_FILE = 8181 / 80;
int bansCounter = 0;
var part = new List<int>();
var maxNumberOfFiles = 10;
Stopwatch timer = new Stopwatch();
var fileCounter = 0;
if (!Directory.Exists(path))
{
DirectoryInfo di = Directory.CreateDirectory(path);
}
try
{
while (fileCounter <= maxNumberOfFiles)
{
timer.Start();
Console.WriteLine("Start writing the bank numbers to file system");
// Console.WriteLine(timer.Start());
foreach (var bank in BankAcoutNumbers.BANS)
{
part.Add(bank);
if (++bansCounter >= BANS_PER_FILE)
{
string fileName = string.Format("{0}.txt-{1}.txt", part[0], part[part.Count - 1]);
string outputToFile = "";// Otherwise you dont see the lines in the file. Just single line!!
string subString = System.IO.Path.Combine(path, "nr");//Needed to add, because otherwise the files will not stored in the correct folder!!
fileName = subString + fileName;
foreach (var partBan in part)
{
using(StreamWriter st = new StreamWriter(fileName))
{
System.IO.File.WriteAllText(fileName, outputToFile);
}
//Console.WriteLine(partBan);
// outputToFile += partBan + Environment.NewLine;//Writing the lines to the file
}
;//Writes to file system.
part.Clear();
bansCounter = 0;
//System.IO.File.WriteAllText(fileName, part.ToString());
if (++fileCounter >= MAX_FILES)
break;
}
}
}
timer.Stop();
Console.WriteLine("Total time of writing the bank numbers to file system " + timer.Elapsed.Seconds + " seconds");
//Console.WriteLine(BankAcoutNumbers.BANS.Count());
}
catch (Exception)
{
throw;
}
System.Console.WriteLine("Press any key to exit.");
System.Console.ReadKey();
}
我这样试试：
foreach（var partBan in part） { 使用（StreamWriter st = new StreamWriter（fileName）） {
System.IO.File.WriteAllText(fileName, outputToFile); } //Console.WriteLine(partBan); // outputToFile += partBan + Environment.NewLine;//Writing the lines to the file }
谢谢
我这样试试：
foreach (var partBan in part)
{
using(StreamWriter st = new StreamWriter(fileName))
{
//System.IO.File.WriteAllText(subString, fileName);
st.WriteLine(outputToFile);
}
//Console.WriteLine(partBan);
// outputToFile += partBan + Environment.NewLine;//Writing the lines to the file
}
但我没看到文件的内容。文件为空
我这样试试：
public class Program
{
static void Main(string[] args)
{
string path = @"C:\BankNumber";
var bans = BankAcoutNumbers.BANS;
const int MAX_FILES = 80;
const int BANS_PER_FILE = 81818182 / 80;
int bansCounter = 0;
var part = new List<int>();
var maxNumberOfFiles = 10;
Stopwatch timer = new Stopwatch();
var fileCounter = 0;
if (!Directory.Exists(path))
{
DirectoryInfo di = Directory.CreateDirectory(path);
}
try
{
while (fileCounter <= maxNumberOfFiles)
{
timer.Start();
Console.WriteLine("Start writing the bank numbers to file system");
// Console.WriteLine(timer.Start());
foreach (var bank in BankAcoutNumbers.BANS)
{
part.Add(bank);
if (++bansCounter >= BANS_PER_FILE)
{
string fileName = string.Format("{0}.txt-{1}.txt", part[0], part[part.Count - 1]);
//string outputToFile = "";// Otherwise you dont see the lines in the file. Just single line!!
StringBuilder OutputFile = new StringBuilder("");
string subString = System.IO.Path.Combine(path, "nr");//Needed to add, because otherwise the files will not stored in the correct folder!!
fileName = subString + fileName;
foreach (var partBan in part)
{
OutputFile.Append(string.Format("{0}{1}", partBan.ToString(), Environment.NewLine));
//using(StreamWriter st = new StreamWriter(fileName))
//{
// //System.IO.File.WriteAllText(subString, fileName);
// StringBuilder strBuilder = new StringBuilder();
// strBuilder.Append(st.)
// st.Write(partBan + Environment.NewLine);
//}
//Console.WriteLine(partBan);
// outputToFile += partBan + Environment.NewLine;//Writing the lines to the file
}
//;//Writes to file system.
System.IO.File.WriteAllText(fileName, OutputFile.ToString());
part.Clear();
bansCounter = 0;
//System.IO.File.WriteAllText(fileName, part.ToString());
if (++fileCounter >= MAX_FILES)
break;
}
}
}
timer.Stop();
Console.WriteLine("Total time of writing the bank numbers to file system " + timer.Elapsed.TotalSeconds + " seconds");
//Console.WriteLine(BankAcoutNumbers.BANS.Count());
}
catch (Exception)
{
throw;
}
foreach (var item in part)
{
ThreadPool.QueueUserWorkItem(DoLongTask);
}
Console.WriteLine("Main thread ends");
System.Console.WriteLine("Press any key to exit.");
System.Console.ReadKey();
}
public static void DoLongTask(object input)
{
Console.WriteLine("Thread is background : {0}", Thread.CurrentThread.IsBackground);
Console.WriteLine("Input parameter : {0}", input);
}
}
答案 0 :(得分：0)
WriteAllText并不比StreamWriter慢。 从.Net源代码中可以看出WriteAllText的工作原理：
private static void InternalWriteAllText(string path,
string contents, Encoding encoding)
{
Contract.Requires(path != null);
Contract.Requires(encoding != null);
Contract.Requires(path.Length > 0);
using (StreamWriter sw = new StreamWriter(path, false, encoding))
sw.Write(contents);
}
缓慢是由字符串引起的。如果用StringBuilder替换字符串性能会提高。检查此代码：
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
namespace ConsoleApplication1
{
class BankAcoutNumbers
{
public List<int> BANS { get; set; }
public BankAcoutNumbers()
{
BANS = new List<int>();
BANS.Add(1456456465);
BANS.Add(2456465);
BANS.Add(342346465);
BANS.Add(445645646);
BANS.Add(545636546);
BANS.Add(64556465);
BANS.Add(7456465);
BANS.Add(842346465);
BANS.Add(9456456);
BANS.Add(10456365);
BANS.Add(11456456);
BANS.Add(12456465);
BANS.Add(1342346);
BANS.Add(1445645);
BANS.Add(1545636);
BANS.Add(1645645);
BANS.Add(1745646);
BANS.Add(1842345);
BANS.Add(194564);
BANS.Add(2045635);
BANS.Add(214564);
BANS.Add(224564);
BANS.Add(234234);
BANS.Add(244564);
BANS.Add(254563);
}
}
class Program
{
static void Main(string[] args)
{
string path = @"C:\";
//string fileName = string.Format("{0}{1}-", part[0], part[part.Count - 1]);
//var bans = BankAcoutNumbers.BANS;
const int MAX_FILES = 10;
const int BANS_PER_FILE = 10;
int bansCounter = 0;
var part = new List<int>();
//string fileName = string.Format("{0}-{1}", part[0], part[part.Count - 1]);
var maxNumberOfFiles = 10;
Stopwatch timer = new Stopwatch();
var fileCounter = 0;
if (!Directory.Exists(path))
{
DirectoryInfo di = Directory.CreateDirectory(path);
}
//var destiNationFile = new StreamWriter(string.Format(fileName, fileCounter + 1));
try
{
// foreach (var bank in BankAcoutNumbers.BANS.Take(100))
//{
while (fileCounter <= maxNumberOfFiles)
{
timer.Start();
foreach (var bank in new BankAcoutNumbers().BANS)
{
part.Add(bank);
if (++bansCounter >= BANS_PER_FILE)
{
string fileName = string.Format("{0}-{1}", part[0], part[part.Count - 1]);
StringBuilder outputToFile = new StringBuilder("");
//var destinationFile = new StreamWriter(fileName);
//destiNationFile = new StreamWriter(fileName);
Console.WriteLine("NR{0}", fileName);
fileName = @"C:\" + fileName;
foreach (var partBan in part)
{
outputToFile.Append(string.Format("{0}{1}", partBan , Environment.NewLine));
Console.WriteLine(partBan);
}
System.IO.File.WriteAllText(fileName, outputToFile.ToString());
part.Clear();
bansCounter = 0;
if (++fileCounter >= MAX_FILES)
break;
}
}
}
timer.Stop();
Console.WriteLine(timer.Elapsed.Seconds);
}
catch (Exception)
{
throw;
}
// Keep the console window open in debug mode.
System.Console.WriteLine("Press any key to exit.");
System.Console.ReadKey();
}
}
}