你如何从MemoryStream中获取字符串？

从 MemoryStream 中获取字符串的方法取决于字符串的编码方式。以下是使用不同编码方式从 MemoryStream 中获取字符串的方法：

ASCII 编码

MemoryStream memoryStream = new MemoryStream();
StreamWriter writer = new StreamWriter(memoryStream, Encoding.ASCII);
writer.Write("Hello, world!");
writer.Flush();
memoryStream.Position = 0;

StreamReader reader = new StreamReader(memoryStream, Encoding.ASCII);
string result = reader.ReadToEnd();

UTF-8 编码

MemoryStream memoryStream = new MemoryStream();
StreamWriter writer = new StreamWriter(memoryStream, Encoding.UTF8);
writer.Write("你好，世界！");
writer.Flush();
memoryStream.Position = 0;

StreamReader reader = new StreamReader(memoryStream, Encoding.UTF8);
string result = reader.ReadToEnd();

Unicode 编码

MemoryStream memoryStream = new MemoryStream();
StreamWriter writer = new StreamWriter(memoryStream, Encoding.Unicode);
writer.Write("你好，世界！");
writer.Flush();
memoryStream.Position = 0;

StreamReader reader = new StreamReader(memoryStream, Encoding.Unicode);
string result = reader.ReadToEnd();

请注意，在使用完 StreamReader 和 MemoryStream 对象后，需要释放资源。可以使用 using 语句来实现资源的自动释放。