Wrong parameter type in Mpr WNetUseConnection

[nsprljan]

I use JNA 4.3.0, but use of Mpr lib should be the same in the latest.

The following function:
WNetUseConnection(HWND hwndOwner, NETRESOURCE lpNETRESOURCE, String lpPassword, String lpUserID, int dwFlags, PointerByReference lpAccessName, IntByReference lpBufferSize, IntByReference lpResult);

has PointerByReference type used for parameter lpAccessName, but it seems to me it should be char[].

MSDN WNetUseConnection() has it as LPSTR lpAccessName

In my implementation only char[] works, while PointerByReference does not (getValue().getString(0)). I guess there could be some way to dance around the returned PointerByReference to get the string out of it, but I haven't found it.

[twall]

According to the docs, you need to provide a buffer to be filled in (make sure it's at least as large as lpRemoteName). PointerByReference only gives you a buffer the size of a pointer. You might be better off with byte[] and using Native.toString(byte[]) to convert it to String. 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. On Mon, Sep 10, 2018 at 12:43 PM Nikola Sprljan ***@***.***> wrote: I use JNA 4.3.0, but use of Mpr lib should be the same in the latest. The following function: WNetUseConnection(HWND hwndOwner, NETRESOURCE lpNETRESOURCE, String lpPassword, String lpUserID, int dwFlags, PointerByReference lpAccessName, IntByReference lpBufferSize, IntByReference lpResult); has PointerByReference type used for parameter lpAccessName, but it seems to me it should be char[]. MSDN WNetUseConnection() has it as LPSTR lpAccessName In my implementation only char[] works, while PointerByReference does not (getValue().getString(0)). I guess there could be some way to dance around the returned PointerByReference to get the string out of it, but I haven't found it. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#1010>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAuMrc9X5HyY48_2yxKE2tEa4mgbjudtks5uZpbBgaJpZM4Whxie> .

[matthiasblaesing]

I would just use a Memory object - this is the adaption for the MprTest for testing:

            Memory lpAccessName;
            if(DEFAULT_OPTIONS==UNICODE_OPTIONS) {
                lpAccessName = new Memory((WinDef.MAX_PATH + 1) * Native.WCHAR_SIZE);
            } else {
                lpAccessName = new Memory(WinDef.MAX_PATH + 1);
            }
            IntByReference lpAccessNameSize = new IntByReference(WinDef.MAX_PATH);
            assertEquals(WinError.ERROR_SUCCESS, Mpr.INSTANCE.WNetUseConnection(null, resource, null, null, 0, lpAccessName, lpAccessNameSize, null));
            System.out.println("Size: " + lpAccessNameSize.getValue());
            if(DEFAULT_OPTIONS==UNICODE_OPTIONS) {
                System.out.println("lpAccessName: " + lpAccessName.getWideString(0));
            } else {
                System.out.println("lpAccessName: " + lpAccessName.getString(0));
            }

This demonstrates the code necessary, so that both calling variants are supported.

[nsprljan]

Yes, that works and is much better than a plain char/byte array - thanks Matthias!