Csharp/CSharp Tutorial/File Directory Stream/StreamReader
Содержание
- 1 A FileReader
- 2 Create StreamReader from a URL
- 3 Create StreamReader through FileStream
- 4 Create StringReader from String
- 5 Demonstrate StringReader and StringWriter
- 6 Read decimal, string and char from a file using FileStream and StreamReader
- 7 Read one character at a time
- 8 StreamReader: ReadLine
- 9 StreamReader: ReadToEnd()
- 10 Stream Read with StreamReader
- 11 Use StreamReader to read a line from a text file
A FileReader
To perform character-based file operations, you wrap a FileStream inside either a StreamReader or a StreamWriter.
<source lang="csharp">using System;
using System.IO;
class MainClass {
public static void Main() {
FileStream fin;
string s;
try {
fin = new FileStream("test.txt", FileMode.Open);
}
catch(FileNotFoundException exc) {
Console.WriteLine(exc.Message + "Cannot open file.");
return ;
}
StreamReader fstr_in = new StreamReader(fin);
// Read the file line-by-line.
while((s = fstr_in.ReadLine()) != null) {
Console.WriteLine(s);
}
fstr_in.Close();
}
}</source>
asdfasdf
Create StreamReader from a URL
<source lang="csharp">using System; using System.Collections.Generic; using System.Text; using System.Net; using System.IO; class MainClass {
static void Main(string[] args)
{
StreamReader reader = new StreamReader(WebRequest.Create("http://www.nfex.ru").GetResponse().GetResponseStream());
string line;
while ((line = reader.ReadLine()) != null)
{
Console.WriteLine(line);
}
}
}</source>
<HTML>
<HEAD>
Java examples (example source code) Organized by topic </title>
...
Create StreamReader through FileStream
<source lang="csharp">using System; using System.IO; public class MainClass {
static void Main(string[] args)
{
FileStream MyFileStream = new FileStream(@"c:\Testing.txt", FileMode.Open, FileAccess.Read, FileShare.None);
StreamReader MyStreamReader = new StreamReader(MyFileStream);
for (int i = 0; i < 99; i++)
{
int ch = MyStreamReader.Read();
Console.WriteLine(ch);
}
MyStreamReader.Close();
}
}</source>
Create StringReader from String
<source lang="csharp">using System; using System.IO; using System.Text; class MainClass {
public static void Main()
{
StringBuilder sb = new StringBuilder();
StringWriter sw = new StringWriter(sb);
sw.Write("This is a test of the StringWriter class");
sw.Close();
StringReader sr = new StringReader(sb.ToString());
string EntireString;
EntireString = sr.ReadToEnd();
Console.WriteLine(EntireString);
sr.Close();
}
}</source>
This is a test of the StringWriter class
Demonstrate StringReader and StringWriter
<source lang="csharp">using System; using System.IO;
class MainClass {
public static void Main() {
StringWriter strwtr = new StringWriter();
for(int i=0; i < 10; i++)
strwtr.WriteLine("This is i: " + i);
StringReader strrdr = new StringReader(strwtr.ToString());
string str = strrdr.ReadLine();
while(str != null) {
str = strrdr.ReadLine();
Console.WriteLine(str);
}
}
}</source>
This is i: 1 This is i: 2 This is i: 3 This is i: 4 This is i: 5 This is i: 6 This is i: 7 This is i: 8 This is i: 9
Read decimal, string and char from a file using FileStream and StreamReader
<source lang="csharp">using System; using System.IO; using System.Text; static class MainClass {
static void Main()
{
// Create a new file.
using (FileStream fs = new FileStream("test.txt", FileMode.Create))
{
using (StreamWriter w = new StreamWriter(fs, Encoding.UTF8))
{
// Write a decimal, string, and char.
w.WriteLine(124.23M);
w.WriteLine("Test string");
w.WriteLine("A");
}
}
// Open the file in read-only mode.
using (FileStream fs = new FileStream("test.txt", FileMode.Open))
{
using (StreamReader r = new StreamReader(fs, Encoding.UTF8))
{
// Read the data and convert it to the appropriate data type.
Console.WriteLine(Decimal.Parse(r.ReadLine()));
Console.WriteLine(r.ReadLine());
Console.WriteLine(Char.Parse(r.ReadLine()));
}
}
}
}</source>
124.23 Test string A
Read one character at a time
<source lang="csharp">using System; using System.IO; public class MainClass {
static void Main(string[] args)
{
StreamReader MyStreamReader = new StreamReader(@"c:\Projects\Testing.txt");
for (int i = 0; i < 99; i++)
{
int ch = MyStreamReader.Read();
Console.WriteLine(ch);
}
MyStreamReader.Close();
}
}</source>
StreamReader: ReadLine
<source lang="csharp">using System; using System.IO; public class MainClass {
static void Main(string[] args)
{
StreamReader MyStreamReader = new StreamReader(@"c:\Test.txt");
string str = MyStreamReader.ReadLine();
Console.WriteLine(str);
MyStreamReader.Close();
}
}</source>
StreamReader: ReadToEnd()
<source lang="csharp">using System; using System.IO; public class MainClass {
static void Main(string[] args)
{
StreamReader MyStreamReader = new StreamReader(@"c:\Projects\Testing.txt");
string str = MyStreamReader.ReadToEnd();
Console.WriteLine(str);
MyStreamReader.Close();
}
}</source>
Stream Read with StreamReader
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.IO;
class Program
{
static void Main(string[] args)
{
FileStream aFile = new FileStream("Log.txt", FileMode.Open);
StreamReader sr = new StreamReader(aFile);
string strLine = sr.ReadLine();
while (strLine != null)
{
Console.WriteLine(strLine);
strLine = sr.ReadLine();
}
sr.Close();
}
}</source>
Use StreamReader to read a line from a text file
<source lang="csharp">using System; using System.IO; class MainClass {
public static void Main(string[] args)
{
string filename = "c:\\file.txt";
FileStream f = new FileStream(filename, FileMode.Open);
StreamReader stream = new StreamReader(f);
string line;
line = stream.ReadLine(); // header line
Console.WriteLine(line);
}
}</source>
