C# usb设备的自动退出

using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
using UsbEject;namespace USBDevice
{
public class RemoveUsbDevice
{
public static string strCurUsb = "";
public bool bMonitorFlag = false;
public const int WM_DEVICECHANGE = 0x219;//U盘插入后，OS的底层会自动检测到，然后向应用程序发送“硬件设备状态改变“的消息
public const int DBT_DEVICEARRIVAL = 0x8000; //就是用来表示U盘可用的。一个设备或媒体已被插入一块，现在可用。
public const int DBT_CONFIGCHANGECANCELED = 0x0019; //要求更改当前的配置（或取消停靠码头）已被取消。
public const int DBT_CONFIGCHANGED = 0x0018; //当前的配置发生了变化，由于码头或取消固定。
public const int DBT_CUSTOMEVENT = 0x8006; //自定义的事件发生。 的Windows NT 4.0和Windows 95：此值不支持。
public const int DBT_DEVICEQUERYREMOVE = 0x8001; //审批要求删除一个设备或媒体作品。任何应用程序也不能否认这一要求，并取消删除。
public const int DBT_DEVICEQUERYREMOVEFAILED = 0x8002; //请求删除一个设备或媒体片已被取消。
public const int DBT_DEVICEREMOVECOMPLETE = 0x8004; //一个设备或媒体片已被删除。
public const int DBT_DEVICEREMOVEPENDING = 0x8003; //一个设备或媒体一块即将被删除。不能否认的。
public const int DBT_DEVICETYPESPECIFIC = 0x8005; //一个设备特定事件发生。
public const int DBT_DEVNODES_CHANGED = 0x0007; //一种设备已被添加到或从系统中删除。
public const int DBT_QUERYCHANGECONFIG = 0x0017; //许可是要求改变目前的配置（码头或取消固定）。
public const int DBT_USERDEFINED = 0xFFFF; //此消息的含义是用户定义的
public const uint GENERIC_READ = 0x80000000;
public const int GENERIC_WRITE = 0x40000000;
public const int FILE_SHARE_READ = 0x1;
public const int FILE_SHARE_WRITE = 0x2;
public const int IOCTL_STORAGE_EJECT_MEDIA = 0x2d4808; [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
private static extern IntPtr CreateFile(
string lpFileName,
uint dwDesireAccess,
uint dwShareMode,
IntPtr SecurityAttributes,
uint dwCreationDisposition,
uint dwFlagsAndAttributes,
IntPtr hTemplateFile); [DllImport("kernel32.dll", ExactSpelling = true, SetLastError = true, CharSet = CharSet.Auto)]
private static extern bool DeviceIoControl(
IntPtr hDevice,
uint dwIoControlCode,
IntPtr lpInBuffer,
uint nInBufferSize,
IntPtr lpOutBuffer,
uint nOutBufferSize,
out uint lpBytesReturned,
IntPtr lpOverlapped
); /// <summary>
/// 卸载当前指定的U盘存储设备
/// </summary>
/// <returns>卸载结果</returns>
public static bool RemoveUsb(string name, string type)
{
try
{
//第一个参数filename与普通文件名有所不同，设备驱动的“文件名”(常称为“设备路径”)形式固定为“\\.\DeviceName”, 如 string filename = @"\\.\I:";
//string filename = @"\\.\" + strCurUsb.Remove(2);
string filename = @"\\.\" + name;
if (type == "1")
{
filename = @"\\.\" + name.Substring(0, 2);
}
//打开设备，得到设备的句柄handle.
IntPtr handle = CreateFile(filename, GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, IntPtr.Zero, 0x3, 0, IntPtr.Zero); // 向目标设备发送设备控制码，也就是发送命令。IOCTL_STORAGE_EJECT_MEDIA 弹出U盘。
uint byteReturned;
bool result = DeviceIoControl(handle, IOCTL_STORAGE_EJECT_MEDIA, IntPtr.Zero, 0, IntPtr.Zero, 0, out byteReturned, IntPtr.Zero); return result;
}
catch (Exception ex)
{
Log.Error("RemoveUsb:" + ex);
return true;
}
} public static void RemoveUsbbydll(string name, string type)
{
try
{ VolumeDeviceClass volumeDeviceClass = new VolumeDeviceClass();
foreach (Volume device in volumeDeviceClass.Devices)
{
// is this volume on USB disks?
if (!device.IsUsb)
{
continue;
}
// is this volume a logical disk?
if ((device.LogicalDrive == null) || (device.LogicalDrive.Length == 0))
{
continue;
}
string filename = name;
if (type == "1")
{
filename = name.Substring(0, 2);
}
if (device.LogicalDrive == filename)
{
device.Eject(true); // allow Windows to display any relevant UI
break;
}
}
}
catch (Exception ex)
{
Log.Error("RemoveUsbbydll-name:" + ex);
}
} }
}