File.WriteAllText Metodo

public:
 static void WriteAllText(System::String ^ path, System::String ^ contents);

public static void WriteAllText(string path, string contents);

static member WriteAllText : string * string -> unit

Public Shared Sub WriteAllText (path As String, contents As String)

Parametri

Eccezioni

Esempio

Nell'esempio di codice seguente viene illustrato l'uso del WriteAllText metodo per scrivere testo in un file. In questo esempio viene creato un file, se non esiste già e viene aggiunto testo.

using System;
using System.IO;
using System.Text;

class Test
{
    public static void Main()
    {
        string path = @"c:\temp\MyTest.txt";

        // This text is added only once to the file.
        if (!File.Exists(path))
        {
            // Create a file to write to.
            string createText = "Hello and Welcome" + Environment.NewLine;
            File.WriteAllText(path, createText);
        }

        // This text is always added, making the file longer over time
        // if it is not deleted.
        string appendText = "This is extra text" + Environment.NewLine;
        File.AppendAllText(path, appendText);

        // Open the file to read from.
        string readText = File.ReadAllText(path);
        Console.WriteLine(readText);
    }
}

open System
open System.IO

let path = @"c:\temp\MyTest.txt"

// This text is added only once to the file.
if File.Exists path |> not then
    // Create a file to write to.
    let createText =
        "Hello and Welcome" + Environment.NewLine

    File.WriteAllText(path, createText)

// This text is always added, making the file longer over time
// if it is not deleted.
let appendText =
    "This is extra text" + Environment.NewLine

File.AppendAllText(path, appendText)

// Open the file to read from.
let readText = File.ReadAllText path
printfn $"{readText}"

Imports System.IO
Imports System.Text

Public Class Test
    Public Shared Sub Main()
        Dim path As String = "c:\temp\MyTest.txt"

        ' This text is added only once to the file.
        If File.Exists(path) = False Then

            ' Create a file to write to.
            Dim createText As String = "Hello and Welcome" + Environment.NewLine
            File.WriteAllText(path, createText)
        End If

        ' This text is always added, making the file longer over time
        ' if it is not deleted.
        Dim appendText As String = "This is extra text" + Environment.NewLine
        File.AppendAllText(path, appendText)

        ' Open the file to read from.
        Dim readText As String = File.ReadAllText(path)
        Console.WriteLine(readText)
    End Sub
End Class

Commenti

Questo metodo usa la codifica UTF-8 senza una Byte-Order Mark (BOM), quindi l'uso del GetPreamble metodo restituirà una matrice di byte vuota. Se è necessario includere un identificatore UTF-8, ad esempio un contrassegno di ordine dei byte, all'inizio di un file, usare l'overload del WriteAllText(String, String, Encoding) metodo con UTF8 la codifica.

Dato una stringa e un percorso di file, questo metodo apre il file specificato, scrive la stringa nel file e quindi chiude il file.

public:
 static void WriteAllText(System::String ^ path, System::String ^ contents, System::Text::Encoding ^ encoding);

public static void WriteAllText(string path, string contents, System.Text.Encoding encoding);

static member WriteAllText : string * string * System.Text.Encoding -> unit

Public Shared Sub WriteAllText (path As String, contents As String, encoding As Encoding)

Parametri

Eccezioni

Esempio

Nell'esempio di codice seguente viene illustrato l'uso del WriteAllText metodo per scrivere testo in un file. In questo esempio viene creato un file, se non esiste già e viene aggiunto testo.

using System;
using System.IO;
using System.Text;

class Test
{
    public static void Main()
    {
        string path = @"c:\temp\MyTest.txt";

        // This text is added only once to the file.
        if (!File.Exists(path))
        {
            // Create a file to write to.
            string createText = "Hello and Welcome" + Environment.NewLine;
            File.WriteAllText(path, createText, Encoding.UTF8);
        }

        // This text is always added, making the file longer over time
        // if it is not deleted.
        string appendText = "This is extra text" + Environment.NewLine;
        File.AppendAllText(path, appendText, Encoding.UTF8);

        // Open the file to read from.
        string readText = File.ReadAllText(path);
        Console.WriteLine(readText);
    }
}

open System
open System.IO
open System.Text

let path = @"c:\temp\MyTest.txt"

// This text is added only once to the file.
if File.Exists path |> not then
    // Create a file to write to.
    let createText =
        "Hello and Welcome" + Environment.NewLine

    File.WriteAllText(path, createText, Encoding.UTF8)

// This text is always added, making the file longer over time
// if it is not deleted.
let appendText =
    "This is extra text" + Environment.NewLine

File.AppendAllText(path, appendText, Encoding.UTF8)

// Open the file to read from.
let readText = File.ReadAllText path
printfn $"{readText}"

Imports System.IO
Imports System.Text

Public Class Test
    Public Shared Sub Main()
        Dim path As String = "c:\temp\MyTest.txt"
        Dim sw As StreamWriter

        ' This text is added only once to the file.
        If File.Exists(path) = False Then

            ' Create a file to write to.
            Dim createText As String = "Hello and Welcome" + Environment.NewLine
            File.WriteAllText(path, createText, Encoding.UTF8)
        End If

        ' This text is always added, making the file longer over time
        ' if it is not deleted.
        Dim appendText As String = "This is extra text" + Environment.NewLine
        File.AppendAllText(path, appendText, Encoding.UTF8)

        ' Open the file to read from.
        Dim readText As String = File.ReadAllText(path)
        Console.WriteLine(readText)
    End Sub
End Class

Commenti

Data una stringa e un percorso di file, questo metodo apre il file specificato, scrive la stringa nel file usando la codifica specificata e quindi chiude il file. L'handle di file è garantito che venga chiuso da questo metodo, anche se vengono generate eccezioni.