我正在使用 C 在 vs2012 中实现 SQLite Prepare-Statement。
我使用此链接作为教程来捕获每次运行代码时在我的机器上运行的进程。一切正常，除了准备语句不允许我将它放在 do-while 循环之外。如果我把它放在 do-while 循环中，那么我实际上什么都不做，因为每次插入 db 时，prepare-statement 都会再次执行，这是不切实际的。但是，当我将准备语句放在 do-while 循环中并运行代码时，它可以正常工作（但它运行的插入次数与我必须插入的次数一样多）。当我放在 do-while 循环之外时，它会给我一个内存警告和中断。
这是我如何实现 SQLite：
BOOL GetProcessList(sqlite3 *db)
{
HANDLE hProcessSnap;
HANDLE hProcess;
PROCESSENTRY32 pe32;
DWORD dwPriorityClass;
sqlite3_stmt* stmt;
char *errorMessage;
char query[80] = "INSERT INTO Process_list VALUES (?1, ?2, ?3, ?4, ?5);";
// Take a snapshot of all processes in the system.
hProcessSnap = CreateToolhelp32Snapshot( TH32CS_SNAPPROCESS, 0 );
if( hProcessSnap == INVALID_HANDLE_VALUE )
{
printError( TEXT("CreateToolhelp32Snapshot (of processes)") );
return( FALSE );
}
// Set the size of the structure before using it.
pe32.dwSize = sizeof( PROCESSENTRY32 );
// Retrieve information about the first process,
// and exit if unsuccessful
if( !Process32First( hProcessSnap, &pe32 ) )
{
printError( TEXT("Process32First") ); // show cause of failure
CloseHandle( hProcessSnap ); // clean the snapshot object
return( FALSE );
}
// Now walk the snapshot of processes, and
// display information about each process in turn
sqlite3_exec(db, "CREATE TABLE IF NOT EXISTS Process_list("
"Process_ID INT PRIMARY KEY , "
"Thread_count INT , "
"Parent_PID INT , "
"Priority_Base INT , "
"Priority_class INT );", NULL, NULL, &errorMessage);
sqlite3_prepare_v2(db, query,strlen(query), &stmt,NULL); // can't put it here
do
{
_tprintf( TEXT("\n\n=====================================================" ));
_tprintf( TEXT("\nPROCESS NAME: %s"), pe32.szExeFile );
_tprintf( TEXT("\n-------------------------------------------------------" ));
// Retrieve the priority class.
dwPriorityClass = 0;
hProcess = OpenProcess( PROCESS_ALL_ACCESS, FALSE, pe32.th32ProcessID );
if( hProcess == NULL )
{
printError( TEXT("OpenProcess") );
} else {
dwPriorityClass = GetPriorityClass( hProcess );
if( !dwPriorityClass )
{
printError( TEXT("GetPriorityClass") );
}
CloseHandle( hProcess );
}
_tprintf( TEXT("\n Process ID = 0x%08X"), pe32.th32ProcessID );
_tprintf( TEXT("\n Thread count = %d"), pe32.cntThreads );
_tprintf( TEXT("\n Parent process ID = 0x%08X"), pe32.th32ParentProcessID );
_tprintf( TEXT("\n Priority base = %d"), pe32.pcPriClassBase );
if( dwPriorityClass )
_tprintf( TEXT("\n Priority class = %d"), dwPriorityClass );
_tprintf( TEXT("\n"));
//-------------------------------------------------------------------------------
// database insertion of the process information
sqlite3_bind_int64(stmt,1,pe32.th32ProcessID);
sqlite3_bind_int64(stmt,2,pe32.cntThreads);
sqlite3_bind_int64(stmt,3,pe32.th32ParentProcessID);
sqlite3_bind_int64(stmt,4,pe32.pcPriClassBase);
sqlite3_bind_int64(stmt,5,dwPriorityClass);
if(sqlite3_step(stmt) != SQLITE_DONE)
printf("\nPrepare statement failed!\n");
sqlite3_reset(stmt); // the error appears here
sqlite3_finalize(stmt);
//-------------------------------------------------------------------------------
// List the modules and threads associated with this process
ListProcessModules( pe32.th32ProcessID,db );
ListProcessThreads( pe32.th32ProcessID,db );
} while( Process32Next( hProcessSnap, &pe32 ) );
CloseHandle( hProcessSnap );
return( TRUE );
}
所以当我运行代码时，它会告诉我：
那么为什么会发生这种情况以及如何避免这种内存异常呢？谢谢