如果我给了一个MemoryStream,我知道已经填充了一个字符串,我如何得到一个字符串回来?


当前回答

使用StreamReader将MemoryStream转换为字符串。

<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.Position
    memStream.Position = 0

    Dim reader As New StreamReader(memStream)
    Dim str = reader.ReadToEnd()

    ' Reset the position so that subsequent writes are correct.
    memStream.Position = pos

    Return str
End Function

其他回答

我需要集成一个类,需要一个流写在它:

XmlSchema schema;
// ... Use "schema" ...

var ret = "";

using (var ms = new MemoryStream())
{
    schema.Write(ms);
    ret = Encoding.ASCII.GetString(ms.ToArray());
}
//here you can use "ret"
// 6 Lines of code

我创建了一个简单的类,可以帮助减少多次使用的代码行:

public static class MemoryStreamStringWrapper
{
    public static string Write(Action<MemoryStream> action)
    {
        var ret = "";
        using (var ms = new MemoryStream())
        {
            action(ms);
            ret = Encoding.ASCII.GetString(ms.ToArray());
        }

        return ret;
    }
}

然后可以用一行代码替换示例

var ret = MemoryStreamStringWrapper.Write(schema.Write);

使用StreamReader,然后你可以使用ReadToEnd方法返回一个字符串。

稍微修改了Brian的答案,允许可选的读启动管理,这似乎是最简单的方法。可能不是最有效的,但容易理解和使用。

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 later
    Dim Pos = memStream.Position
    memStream.Position = startPos

    Dim reader As New StreamReader(memStream)
    Dim str = reader.ReadToEnd()

    ' reset the position so that subsequent writes are correct
    memStream.Position = Pos

    Return str
End Function

在这种情况下,如果你真的想在MemoryStream中简单地使用ReadToEnd方法,你可以使用这个扩展方法来实现:

public static class SetExtensions
{
    public static string ReadToEnd(this MemoryStream BASE)
    {
        BASE.Position = 0;
        StreamReader R = new StreamReader(BASE);
        return R.ReadToEnd();
    }
}

你可以这样使用这个方法:

using (MemoryStream m = new MemoryStream())
{
    //for example i want to serialize an object into MemoryStream
    //I want to use XmlSeralizer
    XmlSerializer xs = new XmlSerializer(_yourVariable.GetType());
    xs.Serialize(m, _yourVariable);

    //the easy way to use ReadToEnd method in MemoryStream
    MessageBox.Show(m.ReadToEnd());
}

以前的解决方案在涉及编码的情况下不起作用。这是一个“现实生活”的例子,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()));
}