ASP.NET-asp.net 得到上传文件md5值问题？

Question

Html:
<div>
<asp:FileUpload runat="server" ID="fileImg" />

<asp:Button ID="Button4" runat="server" Text="Get MD5 From Stream" OnClick="Button4_Click" />
<asp:Label runat="server" ID="labMsg"></asp:Label>
</div>
后台.cs
protected void Button4_Click(object sender, EventArgs e)
{
string str1 = Com.MD5.MyMD5.GetMD5HashFromStream(fileImg.FileContent);

string str2 = Com.MD5.MyMD5.GetMD5HashFromStream(fileImg.FileContent);

labMsg.Text += "MD5:" + str1 + "</br>";
labMsg.Text += "MD5:" + str2 +"</br>";
}
md5哈希方法：
public static string GetMD5HashFromStream(Stream stream)
{
try
{
System.Security.Cryptography.MD5CryptoServiceProvider md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
byte[] data = md5.ComputeHash(stream);
StringBuilder sBuilder = new StringBuilder();
for (int i = 0; i < data.Length; i++)
{
sBuilder.Append(data[i].ToString("x2"));
}
return sBuilder.ToString();
}
catch (Exception ex)
{
throw new Exception("GetMD5HashFromFile() fail,error:" + ex.Message);
}
}
得到的结果：
MD5:be1dfdd38cccf95e75ce078886110eb4
MD5:d41d8cd98f00b204e9800998ecf8427e

为什么不一样？

Answer 1

读取了Stream之后没有复位，byte[] data = md5.ComputeHash(stream);之后加上
stream.Seek(0, SeekOrigin.Begin);