Question

我正在尝试解析httpListenerRequest的输入流，并且遇到了multipart / form-data的严重问题。

这是一个原始帖子的例子：

POST http://removed/ HTTP/1.1
Content-Type: multipart/form-data; boundary=-------------------------8cf5a569f9a4d4a
Host: removed
Content-Length: 15600
Expect: 100-continue
Proxy-Connection: Keep-Alive



---------------------------8cf5a569f9a4d4a
Content-Disposition: form-data; name="realname"

james
---------------------------8cf5a569f9a4d4a
Content-Disposition: form-data; name="username"

jrb1978
---------------------------8cf5a569f9a4d4a
Content-Disposition: form-data; name="password"

password
---------------------------8cf5a569f9a4d4a
Content-Disposition: form-data; name="public"

0
---------------------------8cf5a569f9a4d4a
Content-Disposition: form-data; name="group"

0
---------------------------8cf5a569f9a4d4a
Content-Disposition: form-data; name="avatar"; filename="Untitled.png"
Content-Type: image/png

?PNG
//jibberish filedata here
---------------------------8cf5a569f9a4d4a

现在我如何获得图像数据？我可以使用流读取器将输入流读取到字符串中以提取前5个表单变量，但我不知道如何将图像数据转换为字符串会破坏图像数据吗？

Answer 1

检查http://msdn.microsoft.com/en-us/library/6196h3wt.aspx以确保您的字符串解码良好。

然后使用此函数将包含图像的字符串部分转换为字节数组：

 Public Shared Function StrToByteArray(str As String) As Byte()
    Dim encoding As New System.Text.UTF8Encoding()
    Return encoding.GetBytes(str)
 End Function 'StrToByteArray

然后使用此函数将字节数组转换为图像：

 Private Function BytesToImage(ByVal ImageBytes() As Byte) As Image
    Dim imgNew As Image
    Dim memImage As New System.IO.MemoryStream(ImageBytes)
    imgNew = Image.FromStream(memImage)
    Return imgNew
 End Function

如何从httpListenerRequest解析文件数据

1 个答案: