Question

几年前我写了这段代码：

int CAssignSelectedColumnDlg::RegistryIntFromData(int iColumnIndex, int iCustomIndex, BOOL bAvoidConflicts, int iNumMeetings)
{
    WORD    wLowWord = MAKEWORD(iColumnIndex, iCustomIndex);
    WORD    wHighWord = MAKEWORD(bAvoidConflicts ? 1 : 0, iNumMeetings);

    return (int)MAKEWPARAM(wLowWord, wHighWord);
}

现在我重温这段代码。我需要引入一个BOOL 0/1的第5个数字。这可能吗？

Answer 1

请注意，iColumnIndex，iCustomIndex和iNumMeetings不能超过255，而应为BYTE。您可以在BOOL lobyte中添加更多hiword个值。返回值应为unsigned int。为了向后兼容，您应该将返回值保留为int。

int foo(int iColumnIndex, int iCustomIndex,
    BOOL bAvoidConflicts, int iNumMeetings, BOOL bFifth)
{
    bAvoidConflicts = !!bAvoidConflicts;
    bFifth = !!bFifth;

    WORD loword = MAKEWORD(iColumnIndex, iCustomIndex);

    BYTE lobyte = (BYTE)(bAvoidConflicts << 0) | (BYTE)(bFifth << 1);
    BYTE hibyte = (BYTE)iNumMeetings;
    WORD hiword = MAKEWORD(lobyte, hibyte);

    return (int)MAKEWPARAM(loword, hiword);
}

并检查值：

unsigned int res = foo(x1, x2, x3, x4, x5);

WORD loword = LOWORD(res);
WORD hiword = HIWORD(res);

BYTE iColumnIndex = LOBYTE(loword);
BYTE iCustomIndex = HIBYTE(loword);
BYTE lobyte       = LOBYTE(hiword);
BYTE iNumMeetings = HIBYTE(hiword);

BOOL bAvoidConflicts = !!(lobyte & 1);
BOOL bFifth = !!(lobyte & 2);

if(x1 != iColumnIndex) printf("error 1\n");
if(x2 != iCustomIndex) printf("error 2\n");
if(x3 != bAvoidConflicts) printf("error 3\n");
if(x4 != iNumMeetings) printf("error 4\n");
if(x5 != bFifth) printf("error 5\n");

当然，如果你只使用一个结构并将值存储为int，bool等，会更容易。

这是添加更多位的不同版本，或强制指示新版本的位。

这些名字现在令人困惑。 bFifth是第五个参数，是第二个位(bit1 << 1)

对于新版本

bit2（第三位！）设置为1

int foo(int iColumnIndex, int iCustomIndex,
    BOOL bAvoidConflicts, int iNumMeetings, BOOL bFifth)
{
    bAvoidConflicts = !!bAvoidConflicts;
    bFifth = !!bFifth;

    WORD loword = MAKEWORD(iColumnIndex, iCustomIndex);

    BOOL bit0 = bAvoidConflicts;
    BOOL bit1 = bFifth;
    BOOL bit2 = 1; //<-- always 1 to indicate new version

    BYTE lobyte = 0;
    lobyte |= (BYTE)(bit0 << 0);
    lobyte |= (BYTE)(bit1 << 1);
    lobyte |= (BYTE)(bit2 << 2);
    //lobyte |= (BYTE)(bit3 << 3);
    //lobyte |= (BYTE)(bit4 << 4);
    //lobyte |= (BYTE)(bit5 << 5);
    //lobyte |= (BYTE)(bit6 << 6);
    //lobyte |= (BYTE)(bit7 << 7);

    WORD hiword = MAKEWORD(lobyte, iNumMeetings);

    return (int)MAKEWPARAM(loword, hiword);
}

可以像以前一样检查

int res = foo(255, 254, 1, 253, 1);

WORD loword = LOWORD(res);
WORD hiword = HIWORD(res);

BYTE iColumnIndex = LOBYTE(loword);
BYTE iCustomIndex = HIBYTE(loword);
BYTE iNumMeetings = HIBYTE(hiword);
BYTE lobyte       = LOBYTE(hiword);

BOOL b0 = !!(lobyte & 1);  //bAvoidConflicts
BOOL b1 = !!(lobyte & 2);  //bFifth
BOOL b2 = !!(lobyte & 4);  //version check
BOOL b3 = !!(lobyte & 8);  //not used
BOOL b4 = !!(lobyte & 16); //not used
BOOL b5 = !!(lobyte & 32); //not used
BOOL b6 = !!(lobyte & 64); //not used
BOOL b7 = !!(lobyte & 128);//not used

在WPARAM中组合5个值

1 个答案: