這是什麼定義指令語法的意思？

Question

這些指令是代碼和工作的一部分。但我不明白他們的語法。我只知道「\」意味着代碼繼續下一行。有誰能夠幫助我？爲什麼有一個「;」。什麼「ADDPOPUPMENU」的意思，爲什麼大寫？

#define ADDPOPUPMENU(hmenu, string) \ 
HMENU hSubMenu = CreatePopupMenu(); \ 
AppendMenu(hmenu, MF_STRING | MF_POPUP, (UINT)hSubMenu, string); 
// Add a menu item 
#define ADDMENUITEM(hmenu, ID, string) \ 
AppendMenu(hSubMenu, MF_STRING, ID, string); 

Answer 1

的代碼定義兩個獨立的宏：

#define ADDPOPUPMENU(hmenu, string) \ 
HMENU hSubMenu = CreatePopupMenu(); \ 
AppendMenu(hmenu, MF_STRING | MF_POPUP, (UINT)hSubMenu, string); 

// Add a menu item 
#define ADDMENUITEM(hmenu, ID, string) \ 
AppendMenu(hSubMenu, MF_STRING, ID, string); 

預處理#define語句簡單地定義文本替換。所以像這樣的代碼：

ADDPOPUPMENU(MyMenu, "Name") 
ADDMENUITEM(MyMenu, MyID, "Item") 

將與編譯階段開始之前，在預處理階段改爲：

HMENU hSubMenu = CreatePopupMenu(); 
AppendMenu(MyMenu, MF_STRING | MF_POPUP, (UINT)hSubMenu, "Name"); 
AppendMenu(hSubMenu, MF_STRING, MyID, "Item");