如果给我一个我知道已经填充了一个String的MemoryStream ，我该如何取回一个String ？
#1楼
以前的解决方案在涉及编码的情况下不起作用。 这是 - 一种“现实生活” - 例如如何正确地做到这一点......
using(var stream = new System.IO.MemoryStream())
{var serializer = new DataContractJsonSerializer(typeof(IEnumerable<ExportData>), new[]{typeof(ExportData)}, Int32.MaxValue, true, null, false); serializer.WriteObject(stream, model); var jsonString = Encoding.Default.GetString((stream.ToArray()));
}
#2楼
此示例显示如何读取和写入MemoryStream的字符串。
Imports System.IOModule Module1Sub Main()' We don't need to dispose any of the MemoryStream ' because it is a managed object. However, just for ' good practice, we'll close the MemoryStream.Using ms As New MemoryStreamDim sw As New StreamWriter(ms)sw.WriteLine("Hello World")' The string is currently stored in the ' StreamWriters buffer. Flushing the stream will ' force the string into the MemoryStream.sw.Flush()' If we dispose the StreamWriter now, it will close ' the BaseStream (which is our MemoryStream) which ' will prevent us from reading from our MemoryStream'sw.Dispose()' The StreamReader will read from the current ' position of the MemoryStream which is currently ' set at the end of the string we just wrote to it. ' We need to set the position to 0 in order to read ' from the beginning.ms.Position = 0Dim sr As New StreamReader(ms)Dim myStr = sr.ReadToEnd()Console.WriteLine(myStr)' We can dispose our StreamWriter and StreamReader ' now, though this isn't necessary (they don't hold ' any resources open on their own).sw.Dispose()sr.Dispose()End UsingConsole.WriteLine("Press any key to continue.")Console.ReadKey()End Sub
End Module
#3楼
你也可以使用
Encoding.ASCII.GetString(ms.ToArray());
我认为效率不高，但我不能发誓。 它还允许您选择不同的编码，而使用StreamReader则必须将其指定为参数。
#4楼
Brian的答案稍加修改，允许可选的读取启动管理，这似乎是最简单的方法。 可能不是最有效，但易于理解和使用。
Public Function ReadAll(ByVal memStream As MemoryStream, Optional ByVal startPos As Integer = 0) As String' reset the stream or we'll get an empty string returned' remember the position so we can restore it laterDim Pos = memStream.PositionmemStream.Position = startPosDim reader As New StreamReader(memStream)Dim str = reader.ReadToEnd()' reset the position so that subsequent writes are correctmemStream.Position = PosReturn str
End Function
#5楼
在这种情况下，如果您真的想以简单的方式在MemoryStream使用ReadToEnd方法，则可以使用此扩展方法来实现此目的：
public static class SetExtensions
{public static string ReadToEnd(this MemoryStream BASE){BASE.Position = 0;StreamReader R = new StreamReader(BASE);return R.ReadToEnd();}
}
并且您可以通过以下方式使用此方法：
using (MemoryStream m = new MemoryStream())
{//for example i want to serialize an object into MemoryStream//I want to use XmlSeralizerXmlSerializer xs = new XmlSerializer(_yourVariable.GetType());xs.Serialize(m, _yourVariable);//the easy way to use ReadToEnd method in MemoryStreamMessageBox.Show(m.ReadToEnd());
}
#6楼
为什么不在MemoryStream类型上创建一个很好的扩展方法？
public static class MemoryStreamExtensions
{static object streamLock = new object();public static void WriteLine(this MemoryStream stream, string text, bool flush){byte[] bytes = Encoding.UTF8.GetBytes(text + Environment.NewLine);lock (streamLock){stream.Write(bytes, 0, bytes.Length);if (flush){stream.Flush();}}}public static void WriteLine(this MemoryStream stream, string formatString, bool flush, params string[] strings){byte[] bytes = Encoding.UTF8.GetBytes(String.Format(formatString, strings) + Environment.NewLine);lock (streamLock){stream.Write(bytes, 0, bytes.Length);if (flush){stream.Flush();}}}public static void WriteToConsole(this MemoryStream stream){lock (streamLock){long temporary = stream.Position;stream.Position = 0;using (StreamReader reader = new StreamReader(stream, Encoding.UTF8, false, 0x1000, true)){string text = reader.ReadToEnd();if (!String.IsNullOrEmpty(text)){Console.WriteLine(text);}}stream.Position = temporary;}}
}
当然，在将这些方法与标准方法结合使用时要小心。 :) ...如果你这样做，你需要使用那个方便的streamLock来实现并发性。
#7楼
此示例显示如何从MemoryStream中读取字符串，其中我使用了序列化（使用DataContractJsonSerializer），将字符串从某个服务器传递到客户端，然后，如何从作为参数传递的字符串中恢复MemoryStream，然后，反序列化MemoryStream。
我使用了不同帖子的部分来执行此示例。
希望这会有所帮助。
using System;
using System.Collections.Generic;
using System.IO;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Json;
using System.Threading;namespace JsonSample
{class Program{static void Main(string[] args){var phones = new List<Phone>{new Phone { Type = PhoneTypes.Home, Number = "28736127" },new Phone { Type = PhoneTypes.Movil, Number = "842736487" }};var p = new Person { Id = 1, Name = "Person 1", BirthDate = DateTime.Now, Phones = phones };Console.WriteLine("New object 'Person' in the server side:");Console.WriteLine(string.Format("Id: {0}, Name: {1}, Birthday: {2}.", p.Id, p.Name, p.BirthDate.ToShortDateString()));Console.WriteLine(string.Format("Phone: {0} {1}", p.Phones[0].Type.ToString(), p.Phones[0].Number));Console.WriteLine(string.Format("Phone: {0} {1}", p.Phones[1].Type.ToString(), p.Phones[1].Number));Console.Write(Environment.NewLine);Thread.Sleep(2000);var stream1 = new MemoryStream();var ser = new DataContractJsonSerializer(typeof(Person));ser.WriteObject(stream1, p);stream1.Position = 0;StreamReader sr = new StreamReader(stream1);Console.Write("JSON form of Person object: ");Console.WriteLine(sr.ReadToEnd());Console.Write(Environment.NewLine);Thread.Sleep(2000);var f = GetStringFromMemoryStream(stream1);Console.Write(Environment.NewLine);Thread.Sleep(2000);Console.WriteLine("Passing string parameter from server to client...");Console.Write(Environment.NewLine);Thread.Sleep(2000);var g = GetMemoryStreamFromString(f);g.Position = 0;var ser2 = new DataContractJsonSerializer(typeof(Person));var p2 = (Person)ser2.ReadObject(g);Console.Write(Environment.NewLine);Thread.Sleep(2000);Console.WriteLine("New object 'Person' arrived to the client:");Console.WriteLine(string.Format("Id: {0}, Name: {1}, Birthday: {2}.", p2.Id, p2.Name, p2.BirthDate.ToShortDateString()));Console.WriteLine(string.Format("Phone: {0} {1}", p2.Phones[0].Type.ToString(), p2.Phones[0].Number));Console.WriteLine(string.Format("Phone: {0} {1}", p2.Phones[1].Type.ToString(), p2.Phones[1].Number));Console.Read();}private static MemoryStream GetMemoryStreamFromString(string s){var stream = new MemoryStream();var sw = new StreamWriter(stream);sw.Write(s);sw.Flush();stream.Position = 0;return stream;}private static string GetStringFromMemoryStream(MemoryStream ms){ms.Position = 0;using (StreamReader sr = new StreamReader(ms)){return sr.ReadToEnd();}}}[DataContract]internal class Person{[DataMember]public int Id { get; set; }[DataMember]public string Name { get; set; }[DataMember]public DateTime BirthDate { get; set; }[DataMember]public List<Phone> Phones { get; set; }}[DataContract]internal class Phone{[DataMember]public PhoneTypes Type { get; set; }[DataMember]public string Number { get; set; }}internal enum PhoneTypes{Home = 1,Movil = 2}
}
#8楼
byte[] array = Encoding.ASCII.GetBytes("MyTest1 - MyTest2");
MemoryStream streamItem = new MemoryStream(array);// convert to string
StreamReader reader = new StreamReader(streamItem);
string text = reader.ReadToEnd();
#9楼
使用StreamReader ，然后您可以使用返回字符串的ReadToEnd方法。
#10楼
使用StreamReader将MemoryStream转换为String。
<Extension()> _
Public Function ReadAll(ByVal memStream As MemoryStream) As String' Reset the stream otherwise you will just get an empty string.' Remember the position so we can restore it later.Dim pos = memStream.PositionmemStream.Position = 0Dim reader As New StreamReader(memStream)Dim str = reader.ReadToEnd()' Reset the position so that subsequent writes are correct.memStream.Position = posReturn str
End Function