如何:对新建的数据文件进行读取和写入
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.