Windows下两种方法弹出U盘

1. 通过设置IOCTL_STORAGE_EJECT_MEDIA

• 通过CreateFile打开指定盘符的U盘获取设备句柄hDevice
• 通过DeviceIoControl(hDevice,FSCTL_DISMOUNT_VOLUME…)强制关闭其他进程对设备的占用
• 通过DeviceIoControl(hDevice,FSCTL_LOCK_VOLUME…)对设备进行加锁，防止其他进程干扰
• 通过DeviceIoControl(hDevice,IOCTL_STORAGE_MEDIA_REMOVAL…)来禁用阻止删除多媒体设备功能
• 通过DeviceIoControl(hDevice,IOCTL_STORAGE_EJECT_MEDIA…)来弹出设备。
  注意，此方法只是从文件浏览页面删除盘符，并不是真的弹出了设备

static int EjectLogDisk(const char *discId)
{
	DWORD accessMode = GENERIC_WRITE | GENERIC_READ;
	DWORD shareMode = FILE_SHARE_READ | FILE_SHARE_WRITE;
	HANDLE hDevice;
	long bResult = 0;
	DWORD retu = 0;
	DWORD dwError;
	DWORD dwBytesReturned;
	DWORD dwSleepAmount;
	int nTryCount;
	char szDriv[10];

	if(discId == NULL){
		return 0;
	}
	dwSleepAmount = LOCK_TIMEOUT/LOCK_RETRIES;
	sprintf(szDriv,"\\\\.\\%s:",discId);
	hDevice = CreateFile(szDriv,accessMode,shareMode,NULL,OPEN_EXISTING,0,NULL);
	if(hDevice == INVALID_HANDLE_VALUE){
		printf("uninstallusb createfile failed error:%d\n",GetLastError());
		return -1;
	}
#if 1
	//卸载U盘卷，不论是否在使用
	dwBytesReturned = 0;
	if(!DeviceIoControl(hDevice,FSCTL_DISMOUNT_VOLUME,NULL,0,NULL,0,&dwBytesReturned,NULL)){
		printf("deviceIoConrol FSCTL_DISMOUNT_VOLUME failed\n");
	}
	
	//此循环是用于锁定要弹出的U盘设备，如果U盘在使用，则循环等待
	// Do this in a loop until a timeout period has expired
	for(nTryCount = 0;nTryCount < LOCK_RETRIES;nTryCount++){
		if(DeviceIoControl(hDevice,FSCTL_LOCK_VOLUME,NULL,0,NULL,0,&dwBytesReturned,NULL)){
			break;
		}
	}
#endif

	dwBytesReturned = 0;
	PREVENT_MEDIA_REMOVAL PMRBuffer;
	PMRBuffer.PreventMediaRemoval = FALSE;
	if(!DeviceIoControl(hDevice,IOCTL_STORAGE_MEDIA_REMOVAL,&PMRBuffer,sizeof(PREVENT_MEDIA_REMOVAL),NULL,0,&dwBytesReturned,NULL)){
		printf("DeviceIoControl IOCTL_STORAGE_MEDIA_REMOVAL failed:%d\n",GetLastError());
	}
	bResult = DeviceIoControl(hDevice,IOCTL_STORAGE_EJECT_MEDIA,NULL,0,NULL,0,&retu,NULL);
	if(!bResult){
		CloseHandle(hDevice);
		printf("uninstallusb DeviceIoControl failed error:%d\n",GetLastError());
		return -1;
	}
	CloseHandle(hDevice);

	return 0;
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55

2. 通过设置CM_Request_Device_Eject

此方法的作用与从右下角托盘中安全删除并弹出媒体的功能一致，设置之后，设备的错误码为47。并且设备只能通过断上电重新接入电脑才可用。

#include <winioctl.h>
#include "setupapi.h" 
#include "cfgmgr32.h" 
#pragma comment(lib,"setupapi.lib")  

DEVINST GetDrivesDevInstByDiskNumber(long DiskNumber)
{
	GUID* guid = (GUID*)(void*)&GUID_DEVINTERFACE_DISK;

	// Get device interface info set handle for all devices attached to system
	HDEVINFO hDevInfo = SetupDiGetClassDevs(guid, NULL, NULL,
		DIGCF_PRESENT | DIGCF_DEVICEINTERFACE);

	if (hDevInfo == INVALID_HANDLE_VALUE)
	{
		return 0;
	}

	// Retrieve a context structure for a device interface of a device
	// information set.
	DWORD dwIndex = 0;
	SP_DEVICE_INTERFACE_DATA devInterfaceData = {0};
	devInterfaceData.cbSize = sizeof(SP_DEVICE_INTERFACE_DATA);
	BOOL bRet = FALSE;


	PSP_DEVICE_INTERFACE_DETAIL_DATA pspdidd;
	SP_DEVICE_INTERFACE_DATA spdid;
	SP_DEVINFO_DATA spdd;
	DWORD dwSize;

	spdid.cbSize = sizeof(spdid);

	while ( true )
	{
		bRet = SetupDiEnumDeviceInterfaces(hDevInfo, NULL, guid, dwIndex,
			&devInterfaceData);
		if (!bRet)
		{
			break;
		}

		SetupDiEnumInterfaceDevice(hDevInfo, NULL, guid, dwIndex, &spdid);

		dwSize = 0;
		SetupDiGetDeviceInterfaceDetail(hDevInfo, &spdid, NULL, 0, &dwSize,NULL);

		if ( dwSize )
		{
			pspdidd = (PSP_DEVICE_INTERFACE_DETAIL_DATA)HeapAlloc(GetProcessHeap(),HEAP_ZERO_MEMORY, dwSize);
			if ( pspdidd == NULL ) 
			{
				continue; // autsch
			}
			pspdidd->cbSize = sizeof(*pspdidd);
			ZeroMemory((PVOID)&spdd, sizeof(spdd));
			spdd.cbSize = sizeof(spdd);


			long res = SetupDiGetDeviceInterfaceDetail(hDevInfo, &spdid,pspdidd, dwSize, &dwSize, &spdd);
			if ( res )
			{
				HANDLE hDrive = CreateFile(pspdidd->DevicePath, 0,
					FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, NULL, NULL);
				if ( hDrive != INVALID_HANDLE_VALUE )
				{
					STORAGE_DEVICE_NUMBER sdn;
					DWORD dwBytesReturned = 0;
					res = DeviceIoControl(hDrive, IOCTL_STORAGE_GET_DEVICE_NUMBER,NULL, 0, &sdn, sizeof(sdn), &dwBytesReturned, NULL);
					if ( res ) 
					{
						if ( DiskNumber == (long)sdn.DeviceNumber )
						{
							CloseHandle(hDrive);
							SetupDiDestroyDeviceInfoList(hDevInfo);
							return spdd.DevInst;
						}
					}
					CloseHandle(hDrive);
				}
			}
			HeapFree(GetProcessHeap(), 0, pspdidd);
		}
		dwIndex++;
	}

	SetupDiDestroyDeviceInfoList(hDevInfo);

	return 0;
}

static int EjectUSBDisk(char *discId)
{
	DWORD accessMode = GENERIC_WRITE | GENERIC_READ;
	DWORD shareMode = FILE_SHARE_READ | FILE_SHARE_WRITE;
	HANDLE hDevice;
	long bResult = 0;
	DWORD retu = 0;
	DWORD dwError;
	DWORD dwBytesReturned;
	int nTryCount;
	char szDriv[10];

	if(discId == NULL)
	{
		return 0;
	}

	sprintf(szDriv,"\\\\.\\%s:",discId);
	hDevice = CreateFile(szDriv,accessMode,shareMode,NULL,OPEN_EXISTING,0,NULL);
	if(hDevice == INVALID_HANDLE_VALUE)
	{
		printf("uninstallusb createfile failed error:%d\n",GetLastError());
		return -1;
	}

	//使用CM_Request_Device_Eject弹出USB设备
	STORAGE_DEVICE_NUMBER sdn;
	long DiskNumber = -1;
	long res = DeviceIoControl(hDevice,IOCTL_STORAGE_GET_DEVICE_NUMBER,NULL,0,&sdn,sizeof(sdn),&dwBytesReturned,NULL);
	if(!res)
	{
		printf("DeviceIoControl IOCTL_STORAGE_GET_DEVICE_NUMBER failed:%d\n",GetLastError());
		CloseHandle(hDevice);
		return -1;
	}

	CloseHandle(hDevice);
	DiskNumber = sdn.DeviceNumber;
	if(DiskNumber == -1)
	{
		printf("DiskNumber == -1\n");
		return -1;
	}

	DEVINST DevInst = GetDrivesDevInstByDiskNumber(DiskNumber);
	if(DevInst == 0)
	{
		printf("GetDrivesDevInstDiskNumber failed\n");
		return -1;
	}

	ULONG Status = 0;
	ULONG ProblemNumber = 0;
	PNP_VETO_TYPE VetoType = PNP_VetoTypeUnknown;
	char VetoName[MAX_PATH];
	bool bSuccess = false;

	res = CM_Get_Parent(&DevInst,DevInst,0); //disk's parent, e.g. the USB bridge, the SATA controller....
	res = CM_Get_DevNode_Status(&Status,&ProblemNumber,DevInst,0);
	bool IsRemovable = ((Status & DN_REMOVABLE) != 0);

	printf("isremovable:%d\n",IsRemovable);
	long i;
	// try 3 times
	for(i = 0;i < 3;i++)
	{
		VetoName[0] = '\0';
		if(IsRemovable)
		{
			res = CM_Request_Device_Eject(DevInst,&VetoType,VetoName,MAX_PATH,0);
		}
		else
		{
			res = CM_Query_And_Remove_SubTree(DevInst,&VetoType,VetoName,MAX_PATH,0);
		}
		bSuccess = (res == CR_SUCCESS && VetoName[0] == '\0');
		if(bSuccess)
		{
			break;
		}
		else
		{
			Sleep(200);
		}
	}
	if(bSuccess){
		printf("Success\n\n");
	}else{
		printf("failed\n");

	}
	return 0;
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184