WNetUseConnectionA function (winnetwk.h)
The WNetUseConnection function makes a connection to a network resource. The function can redirect a local device to a network resource.
The WNetUseConnection function is similar to the WNetAddConnection3 function. The main difference is that WNetUseConnection can automatically select an unused local device to redirect to the network resource.
Syntax
DWORD WNetUseConnectionA(
[in] HWND hwndOwner,
[in] LPNETRESOURCEA lpNetResource,
[in] LPCSTR lpPassword,
[in] LPCSTR lpUserId,
[in] DWORD dwFlags,
[out] LPSTR lpAccessName,
[in, out] LPDWORD lpBufferSize,
[out] LPDWORD lpResult
);
Parameters
[in] hwndOwner
Handle to a window that the provider of network resources can use as an owner window for dialog boxes. Use this parameter if you set the CONNECT_INTERACTIVE value in the dwFlags parameter.
[in] lpNetResource
Pointer to a NETRESOURCE structure that specifies details of the proposed connection. The structure contains information about the network resource, the local device, and the network resource provider.
You must specify the following members of the NETRESOURCE structure.
The WNetUseConnection function ignores the other members of the NETRESOURCE structure. For more information, see the descriptions following for the dwFlags parameter.
[in] lpPassword
Pointer to a constant null-terminated string that specifies a password to be used in making the network connection.
If lpPassword is NULL, the function uses the current default password associated with the user specified by lpUserID.
If lpPassword points to an empty string, the function does not use a password.
If the connection fails because of an invalid password and the CONNECT_INTERACTIVE value is set in the dwFlags parameter, the function displays a dialog box asking the user to type the password.
[in] lpUserId
Pointer to a constant null-terminated string that specifies a user name for making the connection.
If lpUserID is NULL, the function uses the default user name. (The user context for the process provides the default user name.)
The lpUserID parameter is specified when users want to connect to a network resource for which they have been assigned a user name or account other than the default user name or account.
The user-name string represents a security context. It may be specific to a network provider.
[in] dwFlags
Set of bit flags describing the connection. This parameter can be any combination of the following values.
| Value | Meaning |
|---|---|
|
If this flag is set, the operating system may interact with the user for authentication purposes. |
|
This flag instructs the system not to use any default settings for user names or passwords without offering the user the opportunity to supply an alternative. This flag is ignored unless CONNECT_INTERACTIVE is also set. |
|
This flag forces the redirection of a local device when making the connection.
If the lpLocalName member of NETRESOURCE specifies a local device to redirect, this flag has no effect, because the operating system still attempts to redirect the specified device. When the operating system automatically chooses a local device, the dwType member must not be equal to RESOURCETYPE_ANY. If this flag is not set, a local device is automatically chosen for redirection only if the network requires a local device to be redirected. Windows XP: When the system automatically assigns network drive letters, letters are assigned beginning with Z:, then Y:, and ending with C:. This reduces collision between per-logon drive letters (such as network drive letters) and global drive letters (such as disk drives). Note that previous releases assigned drive letters beginning with C: and ending with Z:. |
|
This flag instructs the operating system to store the network resource connection.
If this bit flag is set, the operating system automatically attempts to restore the connection when the user logs on. The system remembers only successful connections that redirect local devices. It does not remember connections that are unsuccessful or deviceless connections. (A deviceless connection occurs when lpLocalName is NULL or when it points to an empty string.) If this bit flag is clear, the operating system does not automatically restore the connection at logon. |
|
If this flag is set, the operating system prompts the user for authentication using the command line instead of a graphical user interface (GUI). This flag is ignored unless CONNECT_INTERACTIVE is also set.
Windows 2000/NT and Windows Me/98/95: This value is not supported. |
|
If this flag is set, and the operating system prompts for a credential, the credential should be saved by the credential manager. If the credential manager is disabled for the caller's logon session, or if the network provider does not support saving credentials, this flag is ignored. This flag is also ignored unless you set the CONNECT_COMMANDLINE flag.
Windows 2000/NT and Windows Me/98/95: This value is not supported. |
[out] lpAccessName
Pointer to a buffer that receives system requests on the connection. This parameter can be NULL.
If this parameter is specified, and the lpLocalName member of the NETRESOURCE structure specifies a local device, this buffer receives the local device name. If lpLocalName does not specify a device and the network requires a local device redirection, or if the CONNECT_REDIRECT value is set, this buffer receives the name of the redirected local device.
Otherwise, the name copied into the buffer is that of a remote resource. If specified, this buffer must be at least as large as the string pointed to by the lpRemoteName member.
[in, out] lpBufferSize
Pointer to a variable that specifies the size of the lpAccessName buffer, in characters. If the call fails because the buffer is not large enough, the function returns the required buffer size in this location. For more information, see the descriptions of the lpAccessName parameter and the ERROR_MORE_DATA error code in the Return Values section.
[out] lpResult
Pointer to a variable that receives additional information about the connection. This parameter can be the following value.
Return value
If the function succeeds, the return value is NO_ERROR.
If the function fails, the return value is a system error code, such as one of the following values.
| Return code | Description |
|---|---|
|
The caller does not have access to the network resource. |
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The local device specified by the lpLocalName member is already connected to a network resource. |
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The value specified by lpLocalName is invalid. |
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The value specified by the lpRemoteName member is not acceptable to any network resource provider because the resource name is invalid, or because the named resource cannot be located. |
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The value specified by the lpProvider member does not match any provider. |
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The attempt to make the connection was canceled by the user through a dialog box from one of the network resource providers, or by a called resource. |
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A network-specific error occurred. To obtain a description of the error, call the WNetGetLastError function. |
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The caller passed in a pointer to a buffer that could not be accessed. |
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This error is a result of one of the following conditions:
|
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The specified password is invalid and the CONNECT_INTERACTIVE flag is not set. |
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The lpAccessName buffer is too small.
If a local device is redirected, the buffer needs to be large enough to contain the local device name. Otherwise, the buffer needs to be large enough to contain either the string pointed to by lpRemoteName, or the name of the connectable resource whose alias is pointed to by lpRemoteName. If this error is returned, then no connection has been made. |
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The operating system cannot automatically choose a local redirection because all the valid local devices are in use. |
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The operation could not be completed, either because a network component is not started, or because the specified resource name is not recognized. |
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The network is unavailable. |
Remarks
Windows Server 2003 and Windows XP: The WNet functions create and delete network drive letters in the MS-DOS device namespace associated with a logon session because MS-DOS devices are identified by AuthenticationID. (An AuthenticationID is the locally unique identifier, or LUID, associated with a logon session.) This can affect applications that call one of the WNet functions to create a network drive letter under one user logon, but query for existing network drive letters under a different user logon. An example of this situation could be when a user's second logon is created within a logon session, for example, by calling the CreateProcessAsUser function, and the second logon runs an application that calls the GetLogicalDrives function. GetLogicalDrives does not return network drive letters created by a WNet function under the first logon. Note that in the preceding example the first logon session still exists, and the example could apply to any logon session, including a Terminal Services session. For more information, see Defining an MS-DOS Device Name.
Note
The winnetwk.h header defines WNetUseConnection as an alias that automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that is not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows 2000 Professional [desktop apps only] |
| Minimum supported server | Windows 2000 Server [desktop apps only] |
| Target Platform | Windows |
| Header | winnetwk.h |
| Library | Mpr.lib |
| DLL | Mpr.dll |