.net - 如何从 SD 卡读取原始字节？

Question

在 Windows PC 上，有没有办法从通过 USB 读卡器连接的 SD 卡读取原始字节？ SD 卡是从嵌入式系统写入的，根本不使用文件系统，因此我无法使用标准文件访问例程。这类似于 unix dd 实用程序所做的，但我需要将其集成到 .NET 应用程序中。

Answer 1

我不确定这是否有帮助，但假设即使未格式化的磁盘在 Win32 设备命名空间(我认为必须)中获得物理驱动器编号，您也可以扩展显示的代码 here识别驱动器号并从设备上的任何位置读取原始字节。

更新 : 原链接失效了。来自互联网文件馆的代码。有关上下文，请参阅原始博客文章(上面链接)的 Internet Archive 副本:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using Microsoft.Win32.SafeHandles;
using System.Runtime.InteropServices;
using System.IO;

namespace RawDump
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        public enum EMoveMethod : uint
        {
            Begin = 0,
            Current = 1,
            End = 2
        }

        [DllImport("Kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
        static extern uint SetFilePointer(
            [In] SafeFileHandle hFile,
            [In] int lDistanceToMove,
            [Out] out int lpDistanceToMoveHigh,
            [In] EMoveMethod dwMoveMethod);

        [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
        static extern SafeFileHandle CreateFile(string lpFileName, uint dwDesiredAccess,
          uint dwShareMode, IntPtr lpSecurityAttributes, uint dwCreationDisposition,
          uint dwFlagsAndAttributes, IntPtr hTemplateFile);

        [DllImport("kernel32", SetLastError = true)]
        internal extern static int ReadFile(SafeFileHandle handle, byte[] bytes,
           int numBytesToRead, out int numBytesRead, IntPtr overlapped_MustBeZero);

        private void buttonDump_Click(object sender, EventArgs e)
        {
            short FILE_ATTRIBUTE_NORMAL = 0x80;
            short INVALID_HANDLE_VALUE = -1;
            uint GENERIC_READ = 0x80000000;
            uint GENERIC_WRITE = 0x40000000;
            uint CREATE_NEW = 1;
            uint CREATE_ALWAYS = 2;
            uint OPEN_EXISTING = 3;

            SaveFileDialog mySFD = new SaveFileDialog();
            mySFD.FileName = "dump.bin";
            mySFD.InitialDirectory = Path.GetDirectoryName(Application.StartupPath);
            if(mySFD.ShowDialog() == DialogResult.OK)
            {
                SafeFileHandle handleValue = CreateFile(textBoxPath.Text, GENERIC_READ, 0, IntPtr.Zero, OPEN_EXISTING, 0, IntPtr.Zero);
                if (handleValue.IsInvalid)
                {
                    Marshal.ThrowExceptionForHR(Marshal.GetHRForLastWin32Error());
                }

                int offset = int.Parse(textBoxOffset.Text, System.Globalization.NumberStyles.HexNumber);
                int size = int.Parse(textBoxSize.Text, System.Globalization.NumberStyles.HexNumber);
                byte[] buf = new byte[size];
                int read = 0;
                int moveToHigh;
                SetFilePointer(handleValue, offset, out moveToHigh, EMoveMethod.Begin);
                ReadFile(handleValue, buf, size, out read, IntPtr.Zero);
                FileStream myStream = File.OpenWrite(mySFD.FileName);
                myStream.Write(buf, 0, size);
                myStream.Flush();
                myStream.Close();
                handleValue.Close();
            }
        }
    }
}