One error in my code; The parameter resume_handle is in/out => ref not out like in my code;
> -----Original Message----- > From: dotnet discussion [mailto:[EMAIL PROTECTED]]On Behalf Of > Powell, Simon > Sent: Monday, May 20, 2002 2:11 PM > To: [EMAIL PROTECTED] > Subject: Re: [DOTNET] .NET and using APIs > > > Thank you. The attachment was great. Have used code and it works > perfectly. > > Simon Powell > Dresdner Kleinwort Wasserstein > > -----Original Message----- > From: Dumitru Sbenghe [mailto:[EMAIL PROTECTED]] > Sent: 20 May 2002 11:32 > To: [EMAIL PROTECTED] > Subject: Re: [DOTNET] .NET and using APIs > > > Some mistakes in your code > > > [DllImport("netapi32.dll", CharSet=CharSet.Auto)] > > static extern int NetWkstaUserEnum(StringBuilder > > servername, > > int level, > > ref int bufptr, > > int prefmaxlen, > > ref int entriesread, > > ref int totalentries, > > ref int resume_handle); > > The ref params are out params > > [DllImport("netapi32.dll", CharSet=CharSet.Auto)] > static extern int NetWkstaUserEnum(StringBuilder > servername, > int level, > out IntPtr bufptr, > int prefmaxlen, > out int entriesread, > out int totalentries, > out int resume_handle); > > > > [StructLayout(LayoutKind.Sequential)] > > public struct WKSTA_USER_INFO_1 > > { > > public int wkui1_username; > > public int wkui1_logon_domain; > > public int wkui1_oth_domains; > > public int wkui1_logon_server; > > } > > > The struct declaration is > > [StructLayout(LayoutKind.Sequential)] > public struct WKSTA_USER_INFO_1 > { > [MarshalAs(UnmanagedType.LPWStr)] > public string wkui1_username; > [MarshalAs(UnmanagedType.LPWStr)] > public string wkui1_logon_domain; > [MarshalAs(UnmanagedType.LPWStr)] > public string wkui1_oth_domains; > [MarshalAs(UnmanagedType.LPWStr)] > public string wkui1_logon_server; > } > > Why int if you know is a LPWSTR? > > typedef struct _WKSTA_USER_INFO_1 { > LPWSTR wkui1_username; > LPWSTR wkui1_logon_domain; > LPWSTR wkui1_oth_domains; > LPWSTR wkui1_logon_server; > }WKSTA_USER_INFO_1, > > And the call and looping > > > nStructSize = Marshal.SizeOf(wui1); > System.Type typeOfStruct = typeof(WKSTA_USER_INFO_1); > > do > { > nStatus = NetWkstaUserEnum( > strServer, > 1, > out bufptr, > MAX_PREFERRED_LENGTH, > out dwEntriesread, > out dwTotalentries, > out dwResumehandle > ); > // > // If the call succeeds, > // > if ( (nStatus == NERR_SUCCESS) | (nStatus == ERROR_MORE_DATA) ) > { > if (dwEntriesread > 0) > { > // > // Loop through the entries. > // > for (int i = 0; i < dwEntriesread; i++) > { > // Marshal.PtrToStructure((System.IntPtr) > bufptr, wui1); > wui1 = > (WKSTA_USER_INFO_1)Marshal.PtrToStructure(bufptr, typeOfStruct); > // marshal > struct pointer to struct; the second parameter is a System.Type, > which must > denote the type of the structure > Console.WriteLine(wui1.wkui1_username + > wui1.wkui1_logon_domain); > bufptr = (IntPtr)(bufptr.ToInt32() + > nStructSize); // inc the pointer to struct array > } > } > else > { > Console.WriteLine("A system error has > occurred : " + > nStatus); > } > } > } > while(nStatus == ERROR_MORE_DATA); > > You have attached a full console class. > > Dumitru Sbenghe > http://www.dsbenghe.home.ro/ > > > -----Original Message----- > > From: dotnet discussion [mailto:[EMAIL PROTECTED]]On Behalf > > Of Powell, Simon > > Sent: Monday, May 20, 2002 11:02 AM > > To: [EMAIL PROTECTED] > > Subject: [DOTNET] .NET and using APIs > > > > > > I'm trying to use various APIs with C#, in particular using APIs that > > return structs and make use of pointers such as LPBYTE, LPDWORD etc. > > In particular > > I'm trying to use the API NET_API_STATUS NetWkstaUserEnum(LPWSTR > > servername, > > DWORD level, LPBYTE *bufptr, DWORD prefmaxlen, LPDWORD > entriesread, > > LPDWORD totalentries, LPDWORD resumehandle );, but having great > difficulty > > trying to return the data. Below is some of the code written so far. > > > > private void Form1_Load(object sender, System.EventArgs e) > > { > > listView1.Columns.Add("Username", -2, > > HorizontalAlignment.Left); > > listView1.Columns.Add("Domain", -2, > > HorizontalAlignment.Left); > > listView1.Columns.Add("Machine", -2, > > HorizontalAlignment.Left); > > listView1.View = View.Details; > > > > } > > > > [DllImport("netapi32.dll", CharSet=CharSet.Auto)] > > static extern int NetWkstaUserEnum(StringBuilder > > servername, > > int level, > > ref int bufptr, > > int prefmaxlen, > > ref int entriesread, > > ref int totalentries, > > ref int resume_handle); > > > > [DllImport("netapi32.dll")] > > static extern int NetApiBufferFree(int Buffer); > > > > // for use on Win NT/2000 only > > [StructLayout(LayoutKind.Sequential)] > > public struct WKSTA_USER_INFO_0 > > { > > public int wkui0_username; > > } > > > > [StructLayout(LayoutKind.Sequential)] > > public struct WKSTA_USER_INFO_1 > > { > > public int wkui1_username; > > public int wkui1_logon_domain; > > public int wkui1_oth_domains; > > public int wkui1_logon_server; > > } > > > > private const int MAX_PREFERRED_LENGTH = -1; > > private const int NERR_SUCCESS = 0x0; > > private const int ERROR_MORE_DATA = 0x234; > > > > > > private void button1_Click(object sender, > > System.EventArgs > > e) > > { > > StringBuilder strServer = new > > StringBuilder(textBox1.Text); > > int bufptr = 0; > > int dwEntriesread = 0; > > int dwTotalentries = 0; > > int dwResumehandle = 0; > > int nStatus; > > int nStructSize; > > > > WKSTA_USER_INFO_1 wui1 = new > > WKSTA_USER_INFO_1(); > > > > this.listView1.Items.Clear(); > > > > do > > { > > nStatus = NetWkstaUserEnum( > > strServer, > > 1, > > ref bufptr, > > MAX_PREFERRED_LENGTH, > > ref dwEntriesread, > > ref dwTotalentries, > > ref dwResumehandle > > ); > > > > // > > // If the call succeeds, > > // > > if ((nStatus == NERR_SUCCESS) | > > (nStatus == > > ERROR_MORE_DATA)) > > { > > if (dwEntriesread > 0) > > { > > // > > // Loop through the > > entries. > > // > > for (int i = 0; (i < > > dwEntriesread); i++) > > { > > nStructSize = > > Marshal.SizeOf(wui1); > > > > Marshal.PtrToStructure((System.IntPtr) bufptr, wui1); > > > > MessageBox.Show(wui1.wkui1_username); > > > > } > > } > > else > > { > > MessageBox.Show("A > > system error has occurred : " + nStatus); > > > > } > > } > > > > > > } > > while(nStatus == ERROR_MORE_DATA); > > > > NetApiBufferFree(bufptr); > > > > > > } > > > > } > > > > I tried to use the platform documentation as template, but failed > > miserably. If anyone can help or point me in the direction of a good > > book it would be much appreciated. > > > > Simon > > > > > ---------------------------------------------------------------------- > If you have received this e-mail in error or wish to read our e-mail > disclaimer statement and monitoring policy, please refer to > http://www.drkw.com/disc/email/ or contact the sender. > ---------------------------------------------------------------------- > > You can read messages from the DOTNET archive, unsubscribe from DOTNET, or > subscribe to other DevelopMentor lists at http://discuss.develop.com. You can read messages from the DOTNET archive, unsubscribe from DOTNET, or subscribe to other DevelopMentor lists at http://discuss.develop.com.
