一开始按照linux的习惯去编译一个使用了windowsAPI的程序
结果提示：
$ i686-pc-cygwin-g++ screen_catch.c
screen_catch.c: In function ‘int main()’:
screen_catch.c:158:39: warning: ISO C++ forbids converting a string constant to ‘LPSTR {aka char*}’ [-Wwrite-strings]
SaveBitmapToFile(hBmp,"c:\\11.bmp");
^
/tmp/cc2yXn3P.o:screen_catch.c:(.text+0x38): undefined reference to `_imp__CreateDCA@16'
/tmp/cc2yXn3P.o:screen_catch.c:(.text+0x53): undefined reference to `_imp__GetDeviceCaps@8'
/tmp/cc2yXn3P.o:screen_catch.c:(.text+0x6d): undefined reference to `_imp__GetDeviceCaps@8'
/tmp/cc2yXn3P.o:screen_catch.c:(.text+0x83): undefined reference to `_imp__DeleteDC@4'
/tmp/cc2yXn3P.o:screen_catch.c:(.text+0x101): undefined reference to `_imp__GetObjectA@12'
/tmp/cc2yXn3P.o:screen_catch.c:(.text+0x215): undefined reference to `_imp__GetStockObject@4'
/tmp/cc2yXn3P.o:screen_catch.c:(.text+0x251): undefined reference to `_imp__SelectPalette@12'
/tmp/cc2yXn3P.o:screen_catch.c:(.text+0x264): undefined reference to `_imp__RealizePalette@4'
/tmp/cc2yXn3P.o:screen_catch.c:(.text+0x2aa): undefined reference to `_imp__GetDIBits@28'
/tmp/cc2yXn3P.o:screen_catch.c:(.text+0x2cf): undefined reference to `_imp__SelectPalette@12'
/tmp/cc2yXn3P.o:screen_catch.c:(.text+0x2df): undefined reference to `_imp__RealizePalette@4'
/tmp/cc2yXn3P.o:screen_catch.c:(.text+0x48e): undefined reference to `_imp__CreateCompatibleDC@4'
/tmp/cc2yXn3P.o:screen_catch.c:(.text+0x4c7): undefined reference to `_imp__CreateDIBSection@24'
/tmp/cc2yXn3P.o:screen_catch.c:(.text+0x4e1): undefined reference to `_imp__SelectObject@8'
/tmp/cc2yXn3P.o:screen_catch.c:(.text+0x52e): undefined reference to `_imp__BitBlt@36'
/tmp/cc2yXn3P.o:screen_catch.c:(.text+0x556): undefined reference to `_imp__DeleteDC@4'
collect2: error: ld returned 1 exit status
经过网上查找，发现是编译时没有链接到对应的库导致的。找到对应的库
g++ *.cpp -l Gdi32
编译成功。