如何：对新建的数据文件进行读取和写入

  • 项目

System.IO.BinaryWriter 和 System.IO.BinaryReader 类用于写入和读取字符串以外的数据。 下面的示例演示如何创建空文件流，向其写入数据并从中读取数据。

示例将在当前目录中创建名为 Test.data 的数据文件，也就同时创建了相关的 BinaryWriter 和 BinaryReader 对象，并且 BinaryWriter 对象用于向 Test.data 写入整数 0 到 10，这会将文件指针置于文件末尾。 BinaryReader 对象将文件指针设置回原始位置并读取指定的内容。

注意

如果当前目录中已存在 Test.data，则会引发 IOException 异常。 使用文件模型选项 FileMode.Create 而不是 FileMode.CreateNew 以始终创建新文件，而不引发异常。

示例

using System;
using System.IO;

class MyStream
{
    private const string FILE_NAME = "Test.data";

    public static void Main()
    {
        if (File.Exists(FILE_NAME))
        {
            Console.WriteLine($"{FILE_NAME} already exists!");
            return;
        }

        using (FileStream fs = new FileStream(FILE_NAME, FileMode.CreateNew))
        {
            using (BinaryWriter w = new BinaryWriter(fs))
            {
                for (int i = 0; i < 11; i++)
                {
                    w.Write(i);
                }
            }
        }

        using (FileStream fs = new FileStream(FILE_NAME, FileMode.Open, FileAccess.Read))
        {
            using (BinaryReader r = new BinaryReader(fs))
            {
                for (int i = 0; i < 11; i++)
                {
                    Console.WriteLine(r.ReadInt32());
                }
            }
        }
    }
}


// The example creates a file named "Test.data" and writes the integers 0 through 10 to it in binary format.
// It then writes the contents of Test.data to the console with each integer on a separate line.

Imports System.IO

Class MyStream
    Private Const FILE_NAME As String = "Test.data"

    Public Shared Sub Main()
        If File.Exists(FILE_NAME) Then
            Console.WriteLine($"{FILE_NAME} already exists!")
            Return
        End If

        Using fs As New FileStream(FILE_NAME, FileMode.CreateNew)
            Using w As New BinaryWriter(fs)
                For i As Integer = 0 To 10
                    w.Write(i)
                Next
            End Using
        End Using

        Using fs As New FileStream(FILE_NAME, FileMode.Open, FileAccess.Read)
            Using r As New BinaryReader(fs)
                For i As Integer = 0 To 10
                    Console.WriteLine(r.ReadInt32())
                Next
            End Using
        End Using
    End Sub
End Class

' The example creates a file named "Test.data" and writes the integers 0 through 10 to it in binary format.
' It then writes the contents of Test.data to the console with each integer on a separate line.

请参阅