I've had good results with other P/Invoke'd entry points and the
StringBuilder class.
For example, with a slight modification to ReadEventLog's lpBuffer
parameter, the following is an alternative (warning uncompiled code follows):
// create reference to ReadEventLog in advapi32.dll
[DllImport("advapi32.dll", EntryPoint="ReadEventLog")]
public static extern bool ReadEventLog(
int iBackupLogRef,
int iReadFlags,
int iRecordOffset,
[Out] StringBuilder lpBuffer,
int iNumberOfBytesToRead,
out int pnBytesRead,
out int pnMinNumberOfBytesNeeded);
// ...
StringBuilder BufferString = new StringBuilder(1024);
String ReadString = "";
// ...
// call ReadEventLog in advapi32.dll
bool success = ReadEventLog(
iBackupLogRetValue,
EVENTLOG_SEQUENTIAL_READ,
iRecordOffset,
BufferString,
BufferString.Capacity,
out iBytesRead,
out iMinNumberOfBytesNeeded);
// ...
ReadString = BufferString.ToString();
// ...
-- Peter
http://www.peterRitchie.com/
On Tue, 26 Apr 2005 05:05:16 -0400, Pete Lutwyche
<[EMAIL PROTECTED]> wrote:
>Thanks Peter,
>
>I successfully used [DLLImport] with entry points of OpenBackupEventLog,
>GetNumberOfEventLogRecords and CloseEventLog. When it comes to
>ReadEventLog, my (failing) code is as follows:
>
>// create reference to ReadEventLog in advapi32.dll
>[DllImport("advapi32.dll", EntryPoint="ReadEventLog")]
>public static extern bool ReadEventLog(
> int iBackupLogRef,
> int iReadFlags,
> int iRecordOffset,
> [MarshalAs(UnmanagedType.LPArray)] byte[] lpBuffer,
> int iNumberOfBytesToRead,
> out int pnBytesRead,
> out int pnMinNumberOfBytesNeeded);
>
>// call ReadEventLog in advapi32.dll
>bool success = ReadEventLog(
> iBackupLogRetValue,
> EVENTLOG_SEQUENTIAL_READ,
> iRecordOffset,
> myByteArray,
> myByteArray.Length,
> out iBytesRead,
> out iMinNumberOfBytesNeeded);
>
>// output some data
>string strByteArrayAsString = System.Text.ASCIIEncoding.ASCII.GetString
>(myByteArray);
>System.Console.WriteLine("strByteArrayAsString = " + strByteArrayAsString);
>
>Unfortunately, the boolean "success" is always false and myByteArray is
>always empty. Can you see anything obviously wrong?
>
===================================
This list is hosted by DevelopMentor� http://www.develop.com
View archives and manage your subscription(s) at http://discuss.develop.com
