win32常用函数-1

InitializeCriticalSection

The InitializeCriticalSection function initializes a critical section object.

 

VOID InitializeCriticalSection(

 

    LPCRITICAL_SECTION lpCriticalSection          // address of critical section object 

   );        

Parameters

lpCriticalSection

Points to the critical section object.

Return Values

This function does not return a value.

Remarks

The threads of a single process can use a critical section object for mutual-exclusion synchronization. The process is responsible for allocating the memory used by a critical section object, which it can
do by declaring a variable of type CRITICAL_SECTION. Before using a critical section, some thread of the process must call the InitializeCriticalSection function to initialize the object.

Once a critical section object has been initialized, the threads of the process can specify the object in the EnterCriticalSection, TryEnterCriticalSection, or LeaveCriticalSection function to provide mutually
exclusive access to a shared resource. For similar synchronization between the threads of different processes, use a mutex object.

 

A critical section object cannot be moved or copied. The process must also not modify the object, but must treat it as logically opaque. Use only the functions provided in the Win32 application programming
interface (API) to manage critical section objects.

DeleteCriticalSection

The DeleteCriticalSection function releases all resources used by an unowned critical section object.

VOID DeleteCriticalSection(

 

    LPCRITICAL_SECTION lpCriticalSection          // pointer to critical section object 

   );        

 

Parameters

lpCriticalSection

Points to the critical section object.

Return Values

This function does not return a value.

Remarks

Deleting a critical section object releases all system resources used by the object. Once deleted, the critical section object cannot be specified in the EnterCriticalSection, TryEnterCriticalSection, or
LeaveCriticalSection function.

GetLocalTime 


The GetLocalTime function retrieves the current local date and time.

 

VOID GetLocalTime(

 

    LPSYSTEMTIME lpSystemTime       // address of system time structure 

   );        

Parameters

lpSystemTime

Points to a SYSTEMTIME structure to receive the current local date and time.

Return Values

This function does not return a value.

FreeAndNil

Frees an object reference and replaces the reference with Nil.

procedure FreeAndNil(var Obj);

Parameters

var Obj

Object reference to be freed and Nil'd.

Description

FreeAndNil is a procedure used to free the object reference specified by Obj, and sets the object reference to the Nil value.

Use FreeAndNil to ensure that a variable is Nil after you free the object it references. Pass any variable that represents an object as the Obj parameter.

Note:  Do not pass a value for Obj if it is not an instance of TObject or a TObject descendant.

FreeAndNil is a convenience procedure provided for Delphi or C++ Builder products using a VCL version prior to VCL 5