CSDN话题挑战赛第2期
参赛话题:学习笔记
🐋作者简介:博主是一位.Net开发者,同时也是RPA和低代码平台的践行者。
🐬个人主页:会敲键盘的肘子
🐰系列专栏:.Net实用方法总结
🦀专栏简介:博主针对.Net开发和C站问答过程中遇到的问题进行总结,形成本专栏,希望可以帮助到您解决问题。
🐶座右铭:总有一天你所坚持的会反过来拥抱你。

🌈写在前面:
本文主要介绍System.IO命名空间的BinaryWriter 类,介绍其常用的方法和示例说明。
👉本文关键字:System.IO、BinaryWriter类、方法示例、C#
文章目录
.NET中的IO操作命名空间,包含允许读写文件和数据流的类型以及提供基本文件和目录支持的类型。
我们在.NET中的IO操作,经常需要调用一下几个类。
文件流类,负责大文件的拷贝,读写。
Path类中方法,基本都是对字符串(文件名)的操作,与实际文件没多大关系。
File类
File类可以进行一些对小文件拷贝、剪切操作,还能读一些文档文件。
Dirctory类
目录操作,创建文件、删除目录,获取目录下文件名等等。
将二进制中的基元类型写入流并支持用特定的编码写入字符串。
public class BinaryWriter : IAsyncDisposable, IDisposable
示例
下面的代码示例演示如何在文件中存储和检索应用程序设置。
using System;
using System.IO;
using System.Text;
class ConsoleApplication
{
const string fileName = "AppSettings.dat";
static void Main()
{
WriteDefaultValues();
DisplayValues();
}
public static void WriteDefaultValues()
{
using (var stream = File.Open(fileName, FileMode.Create))
{
using (var writer = new BinaryWriter(stream, Encoding.UTF8, false))
{
writer.Write(1.250F);
writer.Write(@"c:\Temp");
writer.Write(10);
writer.Write(true);
}
}
}
public static void DisplayValues()
{
float aspectRatio;
string tempDirectory;
int autoSaveTime;
bool showStatusBar;
if (File.Exists(fileName))
{
using (var stream = File.Open(fileName, FileMode.Open))
{
using (var reader = new BinaryReader(stream, Encoding.UTF8, false))
{
aspectRatio = reader.ReadSingle();
tempDirectory = reader.ReadString();
autoSaveTime = reader.ReadInt32();
showStatusBar = reader.ReadBoolean();
}
}
Console.WriteLine("Aspect ratio set to: " + aspectRatio);
Console.WriteLine("Temp directory is: " + tempDirectory);
Console.WriteLine("Auto save time set to: " + autoSaveTime);
Console.WriteLine("Show status bar: " + showStatusBar);
}
}
}
此类型实现 IDisposable 接口。 使用从此类型派生的任何类型后,应直接或间接释放它。 若要直接释放类型,请在
try/catch块中调用其 Dispose 方法。 若要间接释放类型,请使用using(在 C# 中)或Using(在 Visual Basic 中)等语言构造。 有关详细信息,请参阅接口主题中的 IDisposable Dispose 和“使用实现 IDisposable 的对象”部分。
public virtual System.IO.Stream BaseStream { get; }
示例
下面的代码示例演示如何使用类顶部MemoryStream的BinaryReader类BinaryWriter读取和写入Double内存中的数据。 MemoryStream 仅读取和写入 Byte 数据。
using System;
using System.IO;
class BinaryRW
{
static void Main()
{
int i;
const int arrayLength = 1000;
// Create random data to write to the stream.
Random randomGenerator = new Random();
double[] dataArray = new double[arrayLength];
for(i = 0; i < arrayLength; i++)
{
dataArray[i] = 100.1 * randomGenerator.NextDouble();
}
using(BinaryWriter binWriter =
new BinaryWriter(new MemoryStream()))
{
// Write the data to the stream.
Console.WriteLine("Writing data to the stream.");
for(i = 0; i < arrayLength; i++)
{
binWriter.Write(dataArray[i]);
}
// Create a reader using the stream from the writer.
using(BinaryReader binReader =
new BinaryReader(binWriter.BaseStream))
{
try
{
// Return to the beginning of the stream.
binReader.BaseStream.Position = 0;
// Read and verify the data.
Console.WriteLine("Verifying the written data.");
for(i = 0; i < arrayLength; i++)
{
if(binReader.ReadDouble() != dataArray[i])
{
Console.WriteLine("Error writing data.");
break;
}
}
Console.WriteLine("The data was written " +
"and verified.");
}
catch(EndOfStreamException e)
{
Console.WriteLine("Error writing data: {0}.",
e.GetType().Name);
}
}
}
}
}
public virtual void Close ();
注意:此方法调用 Dispose ,指定
true以释放所有资源。 不需要专门调用 Close 方法。 请确保 Stream 已正确释放每个对象。 可以 StreamusingUsing在 Visual Basic) 中 (或块中声明对象,以确保释放流及其所有资源,或者可以显式调用 Dispose 方法。
public void Dispose ();
public virtual void Flush ();
Boolean 值写入当前流,其中 0 表示 false,1 表示 truepublic virtual void Write (bool value);
参数
value要写入的
Boolean值(0 或 1)。
示例
下面的代码示例演示如何在文件中存储和检索应用程序设置。
using System;
using System.IO;
using System.Text;
class ConsoleApplication
{
const string fileName = "AppSettings.dat";
static void Main()
{
WriteDefaultValues();
DisplayValues();
}
public static void WriteDefaultValues()
{
using (var stream = File.Open(fileName, FileMode.Create))
{
using (var writer = new BinaryWriter(stream, Encoding.UTF8, false))
{
writer.Write(1.250F);
writer.Write(@"c:\Temp");
writer.Write(10);
writer.Write(true);
}
}
}
public static void DisplayValues()
{
float aspectRatio;
string tempDirectory;
int autoSaveTime;
bool showStatusBar;
if (File.Exists(fileName))
{
using (var stream = File.Open(fileName, FileMode.Open))
{
using (var reader = new BinaryReader(stream, Encoding.UTF8, false))
{
aspectRatio = reader.ReadSingle();
tempDirectory = reader.ReadString();
autoSaveTime = reader.ReadInt32();
showStatusBar = reader.ReadBoolean();
}
}
Console.WriteLine("Aspect ratio set to: " + aspectRatio);
Console.WriteLine("Temp directory is: " + tempDirectory);
Console.WriteLine("Auto save time set to: " + autoSaveTime);
Console.WriteLine("Show status bar: " + showStatusBar);
}
}
}
public virtual void Write (byte value);
参数
valueByte
要写入的无符号字节。
示例
下面的代码示例演示如何使用内存作为后盾存储编写二进制数据,然后验证数据是否已正确写入。
using System;
using System.IO;
class BinaryRW
{
static void Main()
{
int i = 0;
// Create random data to write to the stream.
byte[] writeArray = new byte[1000];
new Random().NextBytes(writeArray);
BinaryWriter binWriter = new BinaryWriter(new MemoryStream());
BinaryReader binReader =
new BinaryReader(binWriter.BaseStream);
try
{
// Write the data to the stream.
Console.WriteLine("Writing the data.");
for(i = 0; i < writeArray.Length; i++)
{
binWriter.Write(writeArray[i]);
}
// Set the stream position to the beginning of the stream.
binReader.BaseStream.Position = 0;
// Read and verify the data from the stream.
for(i = 0; i < writeArray.Length; i++)
{
if(binReader.ReadByte() != writeArray[i])
{
Console.WriteLine("Error writing the data.");
return;
}
}
Console.WriteLine("The data was written and verified.");
}
// Catch the EndOfStreamException and write an error message.
catch(EndOfStreamException e)
{
Console.WriteLine("Error writing the data.\n{0}",
e.GetType().Name);
}
}
}
public virtual void Write (byte[] buffer);
参数
bufferByte[]
包含要写入的数据的字节数组。
示例
下面的代码示例演示如何使用内存作为后盾存储编写二进制数据,然后验证数据是否已正确写入。
using System;
using System.IO;
class BinaryRW
{
static void Main()
{
const int arrayLength = 1000;
// Create random data to write to the stream.
byte[] dataArray = new byte[arrayLength];
new Random().NextBytes(dataArray);
BinaryWriter binWriter = new BinaryWriter(new MemoryStream());
// Write the data to the stream.
Console.WriteLine("Writing the data.");
binWriter.Write(dataArray);
// Create the reader using the stream from the writer.
BinaryReader binReader =
new BinaryReader(binWriter.BaseStream);
// Set Position to the beginning of the stream.
binReader.BaseStream.Position = 0;
// Read and verify the data.
byte[] verifyArray = binReader.ReadBytes(arrayLength);
if(verifyArray.Length != arrayLength)
{
Console.WriteLine("Error writing the data.");
return;
}
for(int i = 0; i < arrayLength; i++)
{
if(verifyArray[i] != dataArray[i])
{
Console.WriteLine("Error writing the data.");
return;
}
}
Console.WriteLine("The data was written and verified.");
}
}
public virtual void Write (byte[] buffer, int index, int count);
参数
bufferByte[]
包含要写入的数据的字节数组。
index要从
buffer中读取且要写入流的第一个字节的索引。
count要从
buffer中读取且要写入流的字节数。
示例
下面的代码示例演示如何使用内存编写二进制数据作为后盾存储,然后验证数据是否已正确写入。
using System;
using System.IO;
namespace BinaryRW
{
class Program
{
static void Main(string[] args)
{
const int arrayLength = 1000;
byte[] dataArray = new byte[arrayLength];
byte[] verifyArray = new byte[arrayLength];
new Random().NextBytes(dataArray);
using (BinaryWriter binWriter = new BinaryWriter(new MemoryStream()))
{
Console.WriteLine("Writing the data.");
binWriter.Write(dataArray, 0, arrayLength);
using (BinaryReader binReader = new BinaryReader(binWriter.BaseStream))
{
binReader.BaseStream.Position = 0;
if (binReader.Read(verifyArray, 0, arrayLength) != arrayLength)
{
Console.WriteLine("Error writing the data.");
return;
}
}
}
for (int i = 0; i < arrayLength; i++)
{
if (verifyArray[i] != dataArray[i])
{
Console.WriteLine("Error writing the data.");
return;
}
}
Console.WriteLine("The data was written and verified.");
}
}
}
public virtual void Write (char[] buffer, int index, int count);
参数
bufferChar[]
要从中写出数据的字符数组。
index在开始接收数据时缓存中的字符位置。
count要写入的字符数。
示例
下面的代码示例演示如何使用内存作为后盾存储来读取和写入数据。
using System;
using System.IO;
class BinaryRW
{
static void Main()
{
char[] invalidPathChars = Path.InvalidPathChars;
MemoryStream memStream = new MemoryStream();
BinaryWriter binWriter = new BinaryWriter(memStream);
// Write to memory.
binWriter.Write("Invalid file path characters are: ");
binWriter.Write(
Path.InvalidPathChars, 0, Path.InvalidPathChars.Length);
// Create the reader using the same MemoryStream
// as used with the writer.
BinaryReader binReader = new BinaryReader(memStream);
// Set Position to the beginning of the stream.
memStream.Position = 0;
// Read the data from memory and write it to the console.
Console.Write(binReader.ReadString());
int arraySize = (int)(memStream.Length - memStream.Position);
char[] memoryData = new char[arraySize];
binReader.Read(memoryData, 0, arraySize);
Console.WriteLine(memoryData);
}
}
public virtual void Write (double value);
参数
value要写入的 8 字节浮点值。
示例
下面的代码示例演示如何使用类顶部MemoryStream的BinaryReader类BinaryWriter读取和写入Double内存中的数据。 MemoryStream 仅读取和写入 Byte 数据。
using System;
using System.IO;
class BinaryRW
{
static void Main()
{
int i;
const int arrayLength = 1000;
// Create random data to write to the stream.
Random randomGenerator = new Random();
double[] dataArray = new double[arrayLength];
for(i = 0; i < arrayLength; i++)
{
dataArray[i] = 100.1 * randomGenerator.NextDouble();
}
using(BinaryWriter binWriter =
new BinaryWriter(new MemoryStream()))
{
// Write the data to the stream.
Console.WriteLine("Writing data to the stream.");
for(i = 0; i < arrayLength; i++)
{
binWriter.Write(dataArray[i]);
}
// Create a reader using the stream from the writer.
using(BinaryReader binReader =
new BinaryReader(binWriter.BaseStream))
{
try
{
// Return to the beginning of the stream.
binReader.BaseStream.Position = 0;
// Read and verify the data.
Console.WriteLine("Verifying the written data.");
for(i = 0; i < arrayLength; i++)
{
if(binReader.ReadDouble() != dataArray[i])
{
Console.WriteLine("Error writing data.");
break;
}
}
Console.WriteLine("The data was written " +
"and verified.");
}
catch(EndOfStreamException e)
{
Console.WriteLine("Error writing data: {0}.",
e.GetType().Name);
}
}
}
}
}
public virtual void Write (Half value);
参数
value要写入的双字节浮点值。
示例
下面的代码示例演示如何使用类顶部MemoryStream的BinaryReader类BinaryWriter读取和写入Double内存中的数据。 MemoryStream 仅读取和写入 Byte 数据。
using System;
using System.IO;
class BinaryRW
{
static void Main()
{
int i;
const int arrayLength = 1000;
// Create random data to write to the stream.
Random randomGenerator = new Random();
double[] dataArray = new double[arrayLength];
for(i = 0; i < arrayLength; i++)
{
dataArray[i] = 100.1 * randomGenerator.NextDouble();
}
using(BinaryWriter binWriter =
new BinaryWriter(new MemoryStream()))
{
// Write the data to the stream.
Console.WriteLine("Writing data to the stream.");
for(i = 0; i < arrayLength; i++)
{
binWriter.Write(dataArray[i]);
}
// Create a reader using the stream from the writer.
using(BinaryReader binReader =
new BinaryReader(binWriter.BaseStream))
{
try
{
// Return to the beginning of the stream.
binReader.BaseStream.Position = 0;
// Read and verify the data.
Console.WriteLine("Verifying the written data.");
for(i = 0; i < arrayLength; i++)
{
if(binReader.ReadDouble() != dataArray[i])
{
Console.WriteLine("Error writing data.");
break;
}
}
Console.WriteLine("The data was written " +
"and verified.");
}
catch(EndOfStreamException e)
{
Console.WriteLine("Error writing data: {0}.",
e.GetType().Name);
}
}
}
}
}
public virtual void Write (int value);
参数
value要写入的 4 字节带符号整数。
示例
下面的代码示例演示如何在文件中存储和检索应用程序设置。
using System;
using System.IO;
using System.Text;
class ConsoleApplication
{
const string fileName = "AppSettings.dat";
static void Main()
{
WriteDefaultValues();
DisplayValues();
}
public static void WriteDefaultValues()
{
using (var stream = File.Open(fileName, FileMode.Create))
{
using (var writer = new BinaryWriter(stream, Encoding.UTF8, false))
{
writer.Write(1.250F);
writer.Write(@"c:\Temp");
writer.Write(10);
writer.Write(true);
}
}
}
public static void DisplayValues()
{
float aspectRatio;
string tempDirectory;
int autoSaveTime;
bool showStatusBar;
if (File.Exists(fileName))
{
using (var stream = File.Open(fileName, FileMode.Open))
{
using (var reader = new BinaryReader(stream, Encoding.UTF8, false))
{
aspectRatio = reader.ReadSingle();
tempDirectory = reader.ReadString();
autoSaveTime = reader.ReadInt32();
showStatusBar = reader.ReadBoolean();
}
}
Console.WriteLine("Aspect ratio set to: " + aspectRatio);
Console.WriteLine("Temp directory is: " + tempDirectory);
Console.WriteLine("Auto save time set to: " + autoSaveTime);
Console.WriteLine("Show status bar: " + showStatusBar);
}
}
}
public virtual void Write (float value);
参数
value要写入的 4 字节浮点值。
示例
下面的代码示例演示如何在文件中存储和检索应用程序设置。
using System;
using System.IO;
using System.Text;
class ConsoleApplication
{
const string fileName = "AppSettings.dat";
static void Main()
{
WriteDefaultValues();
DisplayValues();
}
public static void WriteDefaultValues()
{
using (var stream = File.Open(fileName, FileMode.Create))
{
using (var writer = new BinaryWriter(stream, Encoding.UTF8, false))
{
writer.Write(1.250F);
writer.Write(@"c:\Temp");
writer.Write(10);
writer.Write(true);
}
}
}
public static void DisplayValues()
{
float aspectRatio;
string tempDirectory;
int autoSaveTime;
bool showStatusBar;
if (File.Exists(fileName))
{
using (var stream = File.Open(fileName, FileMode.Open))
{
using (var reader = new BinaryReader(stream, Encoding.UTF8, false))
{
aspectRatio = reader.ReadSingle();
tempDirectory = reader.ReadString();
autoSaveTime = reader.ReadInt32();
showStatusBar = reader.ReadBoolean();
}
}
Console.WriteLine("Aspect ratio set to: " + aspectRatio);
Console.WriteLine("Temp directory is: " + tempDirectory);
Console.WriteLine("Auto save time set to: " + autoSaveTime);
Console.WriteLine("Show status bar: " + showStatusBar);
}
}
}
public virtual void Write (string value);
参数
valueString
要写入的 4 字节带符号整数。
示例
下面的代码示例演示如何在文件中存储和检索应用程序设置。
using System;
using System.IO;
using System.Text;
class ConsoleApplication
{
const string fileName = "AppSettings.dat";
static void Main()
{
WriteDefaultValues();
DisplayValues();
}
public static void WriteDefaultValues()
{
using (var stream = File.Open(fileName, FileMode.Create))
{
using (var writer = new BinaryWriter(stream, Encoding.UTF8, false))
{
writer.Write(1.250F);
writer.Write(@"c:\Temp");
writer.Write(10);
writer.Write(true);
}
}
}
public static void DisplayValues()
{
float aspectRatio;
string tempDirectory;
int autoSaveTime;
bool showStatusBar;
if (File.Exists(fileName))
{
using (var stream = File.Open(fileName, FileMode.Open))
{
using (var reader = new BinaryReader(stream, Encoding.UTF8, false))
{
aspectRatio = reader.ReadSingle();
tempDirectory = reader.ReadString();
autoSaveTime = reader.ReadInt32();
showStatusBar = reader.ReadBoolean();
}
}
Console.WriteLine("Aspect ratio set to: " + aspectRatio);
Console.WriteLine("Temp directory is: " + tempDirectory);
Console.WriteLine("Auto save time set to: " + autoSaveTime);
Console.WriteLine("Show status bar: " + showStatusBar);
}
}
}
更多方法请查阅官方文档BinaryWriter类。
⭐写在结尾:
文章中出现的任何错误请大家批评指出,一定及时修改。
希望写在这里的小伙伴能给个三连支持!
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是的,我知道最好使用webmock,但我想知道如何在RSpec中模拟此方法:defmethod_to_testurl=URI.parseurireq=Net::HTTP::Post.newurl.pathres=Net::HTTP.start(url.host,url.port)do|http|http.requestreq,foo:1endresend这是RSpec:let(:uri){'http://example.com'}specify'HTTPcall'dohttp=mock:httpNet::HTTP.stub!(:start).and_yieldhttphttp.shou