Csharp/CSharp Tutorial/File Directory Stream/StreamWriter
Содержание
- 1 Create StringWriter from StringBuilder
- 2 new StreamWriter(fs, Encoding.UTF8)
- 3 Open a file using StreamWriter
- 4 Reading and Writing Files
- 5 Save string, decimal and char using FileStream and StreamWriter
- 6 StreamWriter/Reader App
- 7 Stream Write with StreamWriter
- 8 StringReader/Writer App
- 9 Using File.CreateText to create a text file and return StreamWriter
- 10 Using statement and StreamWriter
- 11 Using StreamWriter: write a portion of an array
- 12 Using StreamWriter: write char
- 13 Using StreamWriter: Writes an Array of characters
- 14 Using StreamWriter: write string
Create StringWriter from StringBuilder
<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
new StreamWriter(fs, Encoding.UTF8)
<source lang="csharp">using System; using System.IO; using System.Text; class MainClass {
static void Main() {
using (FileStream fs = new FileStream("test.txt", FileMode.Create)) {
using (StreamWriter w = new StreamWriter(fs, Encoding.UTF8)) {
w.WriteLine(124.23M);
w.WriteLine("Test string");
w.WriteLine("!");
}
}
Console.WriteLine("Press Enter to read the information.");
Console.ReadLine();
using (FileStream fs = new FileStream("test.txt", FileMode.Open)) {
using (StreamReader r = new StreamReader(fs, Encoding.UTF8)) {
Console.WriteLine(Decimal.Parse(r.ReadLine()));
Console.WriteLine(r.ReadLine());
Console.WriteLine(Char.Parse(r.ReadLine()));
}
}
}
}</source>
Open a file using StreamWriter
<source lang="csharp">using System; using System.IO;
class MainClass {
public static void Main() {
StreamWriter fstr_out;
try {
fstr_out = new StreamWriter("test.txt");
}
catch(IOException exc) {
Console.WriteLine(exc.Message + "Cannot open file.");
return ;
}
try {
fstr_out.Write("asdfasdf");
} catch(IOException exc) {
Console.WriteLine(exc.Message + "File Error");
return ;
}
fstr_out.Close();
}
}</source>
Reading and Writing Files
<source lang="csharp">using System; using System.IO; class MainClass {
public static void Main()
{
FileStream f = new FileStream("output.txt", FileMode.Create);
StreamWriter s = new StreamWriter(f);
s.WriteLine("{0} {1}", "test", 55);
s.Close();
f.Close();
}
}</source>
Save string, decimal and char using FileStream and StreamWriter
<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
StreamWriter/Reader App
<source lang="csharp">using System; using System.Collections.Generic; using System.Text; using System.IO;
class Program
{
static void Main(string[] args)
{
using (StreamWriter writer = new StreamWriter("reminders.txt"))
{
writer.WriteLine("A");
writer.WriteLine("B");
writer.WriteLine("C");
for (int i = 0; i < 10; i++)
writer.Write(i + " ");
writer.Write(writer.NewLine);
}
using (StreamReader sr = new StreamReader("reminders.txt"))
{
string input = null;
while ((input = sr.ReadLine()) != null)
{
Console.WriteLine(input);
}
}
}
}</source>
Stream Write with StreamWriter
<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.OpenOrCreate);
StreamWriter sw = new StreamWriter(aFile);
bool truth = true;
sw.WriteLine("Hello to you.");
sw.WriteLine("It is now {0} and things are looking good.",DateTime.Now.ToLongDateString());
sw.Write("More than that,");
sw.Write(" it"s {0} that C# is fun.", truth);
sw.Close();
}
}</source>
StringReader/Writer App
<source lang="csharp">using System; using System.Collections.Generic; using System.Text; using System.IO;
class Program
{
static void Main(string[] args)
{
using (StringWriter strWriter = new StringWriter())
{
strWriter.WriteLine("A");
Console.WriteLine(strWriter);
StringBuilder sb = strWriter.GetStringBuilder();
sb.Insert(0, "Hey!! ");
Console.WriteLine("-> {0}", sb.ToString());
sb.Remove(0, "Hey!! ".Length);
Console.WriteLine("-> {0}", sb.ToString());
using (StringReader strReader = new StringReader(strWriter.ToString()))
{
string input = null;
while ((input = strReader.ReadLine()) != null)
{
Console.WriteLine(input);
}
}
}
}
}</source>
Using File.CreateText to create a text file and return StreamWriter
<source lang="csharp">using System; using System.Collections.Generic; using System.ruponentModel; using System.Data; using System.Drawing; using System.Windows.Forms; using System.IO;
class MainClass {
public static void Main()
{
StreamWriter Writer;
Writer = File.CreateText("TestResults.log");
Writer.WriteLine("Test Results for Test Run XYZ; " + DateTime.Now);
if (File.Exists("fileName"))
{
Writer.WriteLine("File Exists: Test Passed");
}
else
{
Writer.WriteLine("File Exists: Test Failed");
}
Writer.WriteLine("Test Completed for Test Run XYZ; " + DateTime.Now);
Writer.Close();
}
}</source>
Using statement and StreamWriter
<source lang="csharp">using System; using System.Collections.Generic; using System.ruponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; using System.IO; using System.IO.IsolatedStorage; using System.Security.Permissions; [assembly: IsolatedStorageFilePermission(SecurityAction.RequestMinimum, UsageAllowed = IsolatedStorageContainment.AssemblyIsolationByUser)] public class MainClass{
public static void Main()
{
using (StreamWriter sw = new StreamWriter(@"C:\MyData.txt"))
{
sw.WriteLine("This is my data.");
sw.WriteLine("Cool, huh?");
}
}
}</source>
Using StreamWriter: write a portion of an array
<source lang="csharp">using System; using System.IO; public class MainClass {
static void Main(string[] args)
{
StreamWriter MyStreamWriter = new StreamWriter(@"c:\Testing.txt");
char[] MyCharArray = new char[100];
for (int i = 0; i < 99; i++)
{
MyCharArray[i] = (char)i;
}
MyStreamWriter.Write(MyCharArray, 25, 30);
MyStreamWriter.Close(); }
}</source>
Using StreamWriter: write char
<source lang="csharp">using System; using System.IO; public class MainClass {
static void Main(string[] args)
{
StreamWriter MyStreamWriter = new StreamWriter(@"c:\Testing.txt");
//Writes single characters to a stream
char MyChar = "A";
MyStreamWriter.Write(MyChar);
MyStreamWriter.Close();
}
}</source>
Using StreamWriter: Writes an Array of characters
<source lang="csharp">using System; using System.IO; public class MainClass {
static void Main(string[] args)
{
StreamWriter MyStreamWriter = new StreamWriter(@"c:\Testing.txt");
char[] MyCharArray = new char[100];
for (int i = 0; i < 99; i++)
{
MyCharArray[i] = (char)i;
}
MyStreamWriter.Write(MyCharArray);
MyStreamWriter.Close();
}
}</source>
Using StreamWriter: write string
<source lang="csharp">using System; using System.IO; public class MainClass {
static void Main(string[] args)
{
StreamWriter MyStreamWriter = new StreamWriter(@"c:\Testing.txt");
string MyString = "Hello World";
MyStreamWriter.Write(MyString);
MyStreamWriter.Close();
}
}</source>
