BinaryWriter (Clase)
Ensamblado: mscorlib (en mscorlib.dll)
Una clase derivada puede reemplazar los métodos de esta clase para proporcionar codificaciones únicas de caracteres.
En la siguiente tabla se muestran ejemplos de otras tareas de E/S típicas o relacionadas.
| Para realizar esta operación... | Vea el ejemplo de este tema... |
|---|---|
| Crear un archivo de texto | |
| Escribir en un archivo de texto | |
| Leer de un archivo de texto | |
| Leer de un archivo binario | |
| Escribir en un archivo binario |
En el ejemplo de código siguiente se muestra la forma de almacenar y recuperar valores de configuración de una aplicación en un archivo.
using System; using System.IO; using System.Security.Permissions; class Test { static void Main() { // Load application settings. AppSettings appSettings = new AppSettings(); Console.WriteLine("App settings.\nAspect Ratio: {0}, " + "Lookup directory: {1},\nAuto save time: {2} minutes, " + "Show status bar: {3}\n", new Object[4]{appSettings.AspectRatio.ToString(), appSettings.LookupDir, appSettings.AutoSaveTime.ToString(), appSettings.ShowStatusBar.ToString()}); // Change the settings. appSettings.AspectRatio = 1.250F; appSettings.LookupDir = @"C:\Temp"; appSettings.AutoSaveTime = 10; appSettings.ShowStatusBar = true; // Save the new settings. appSettings.Close(); } } // Store and retrieve application settings. class AppSettings { const string fileName = "AppSettings#@@#.dat"; float aspectRatio; string lookupDir; int autoSaveTime; bool showStatusBar; public float AspectRatio { get{ return aspectRatio; } set{ aspectRatio = value; } } public string LookupDir { get{ return lookupDir; } set{ lookupDir = value; } } public int AutoSaveTime { get{ return autoSaveTime; } set{ autoSaveTime = value; } } public bool ShowStatusBar { get{ return showStatusBar; } set{ showStatusBar = value; } } public AppSettings() { // Create default application settings. aspectRatio = 1.3333F; lookupDir = @"C:\AppDirectory"; autoSaveTime = 30; showStatusBar = false; if(File.Exists(fileName)) { BinaryReader binReader = new BinaryReader(File.Open(fileName, FileMode.Open)); try { // If the file is not empty, // read the application settings. if(binReader.PeekChar() != -1) { aspectRatio = binReader.ReadSingle(); lookupDir = binReader.ReadString(); autoSaveTime = binReader.ReadInt32(); showStatusBar = binReader.ReadBoolean(); } } // If the end of the stream is reached before reading // the four data values, ignore the error and use the // default settings for the remaining values. catch(EndOfStreamException e) { Console.WriteLine("{0} caught and ignored. " + "Using default values.", e.GetType().Name); } finally { binReader.Close(); } } } // Create a file and store the application settings. public void Close() { using(BinaryWriter binWriter = new BinaryWriter(File.Open(fileName, FileMode.Create))) { binWriter.Write(aspectRatio); binWriter.Write(lookupDir); binWriter.Write(autoSaveTime); binWriter.Write(showStatusBar); } } }
import System.*;
import System.IO.*;
import System.Security.Permissions.*;
class Test
{
public static void main(String[] args)
{
// Load application settings.
AppSettings appSettings = new AppSettings();
Console.WriteLine("App settings.\nAspect Ratio: {0}, "
+ "Lookup directory: {1},\nAuto save time: {2} minutes, "
+ "Show status bar: {3}\n",
new Object[]{System.Convert.ToString(appSettings.get_AspectRatio()),
appSettings.get_LookupDir(),
System.Convert.ToString(appSettings.get_AutoSaveTime()),
System.Convert.ToString(appSettings.get_ShowStatusBar())});
// Change the settings.
appSettings.set_AspectRatio(1.25F);
appSettings.set_LookupDir("C:\\Temp");
appSettings.set_AutoSaveTime ( 10);
appSettings.set_ShowStatusBar( true);
// Save the new settings.
appSettings.Close();
} //main
} //Test
// Store and retrieve application settings.
class AppSettings
{
private String fileName = "AppSettings#@@#.dat";
private float aspectRatio;
private String lookupDir;
private int autoSaveTime;
private boolean showStatusBar;
/** @property
*/
public float get_AspectRatio()
{
return aspectRatio ;
}//get_AspectRatio
/** @property
*/
public void set_AspectRatio ( float value )
{
aspectRatio = value;
}//set_AspectRatio
/** @property
*/
public String get_LookupDir()
{
return lookupDir ;
}//get_LookupDir
/** @property
*/
public void set_LookupDir ( String value )
{
lookupDir = value;
}//set_LookupDir
/** @property
*/
public int get_AutoSaveTime()
{
return autoSaveTime ;
}//get_AutoSaveTime
/** @property
*/
public void set_AutoSaveTime ( int value )
{
autoSaveTime = value;
}//set_AutoSaveTime
/** @property
*/
public boolean get_ShowStatusBar()
{
return showStatusBar ;
}//get_ShowStatusBar
/** @property
*/
public void set_ShowStatusBar ( boolean value )
{
showStatusBar = value;
}//set_ShowStatusBar
public AppSettings()
{
// Create default application settings.
aspectRatio = 1.3333F;
lookupDir = "C:\\AppDirectory";
autoSaveTime = 30;
showStatusBar = false;
if ( File.Exists(fileName) ) {
BinaryReader binReader =
new BinaryReader(File.Open(fileName, FileMode.Open));
try {
// If the file is not empty,
// read the application settings.
if ( binReader.PeekChar() !=-1 ) {
aspectRatio = binReader.ReadSingle();
lookupDir = binReader.ReadString();
autoSaveTime = binReader.ReadInt32();
showStatusBar = binReader.ReadBoolean();
}
}
// If the end of the stream is reached before reading
// the four data values, ignore the error and use the
// default settings for the remaining values.
catch(EndOfStreamException e) {
Console.WriteLine("{0} caught and ignored. "
+ "Using default values.", e.GetType().get_Name());
}
finally {
binReader.Close();
}
}
} //AppSettings
// Create a file and store the application settings.
public void Close()
{
BinaryWriter binWriter =
new BinaryWriter(File.Open(fileName, FileMode.Create));
try {
binWriter.Write(aspectRatio);
binWriter.Write(lookupDir);
binWriter.Write(autoSaveTime);
binWriter.Write(showStatusBar);
}
finally {
if ( binWriter != null ) {
binWriter= null;
}
}
} //Close
} //AppSettings
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium, Windows Mobile para Pocket PC, Windows Mobile para Smartphone, Windows Server 2003, Windows XP Media Center, Windows XP Professional x64, Windows XP SP2, Windows XP Starter Edition
.NET Framework no admite todas las versiones de cada plataforma. Para obtener una lista de las versiones admitidas, vea Requisitos del sistema.