保证工具栏分隔符在多次 TB_ADDBUTTONS 调用中的正确间距

引言

我通过单个 TB_ADDBUTTONS 消息调用来创建我的工具栏。我也使用 TB_ADDBUTTONS 消息调用来创建分隔符。但是分隔符的宽度一开始太小，然后随着每个分隔符的增加而增加。

背景

为了获得正确的分隔符宽度（每个 8px），TBSTYLE_SEP 不应单独添加到工具栏。为了解决这个问题，我更改了我的 API 并添加了 bPrependSeparator 参数。结果如下

Using the Code

我知道 - 可以写得更短，但代码可读且能完成它应该做的事情

/// <summary>
/// Adds a new button to the tool bar.
/// </summary>
/// <param name="hBmpImage">The handler of the tool bar button image bitmap.
/// Can be <c>NULL</c>, if <c>byStyle</c> doesn't need an image.</param>
/// <param name="hBmpMask">The handler of the tool bar button mask bitmap.
/// Can be <c>NULL</c>, if transparency is not required.</param>
/// <param name="uiCommandID">The tool bar button command ID, that is in sync
/// with the menu item command ID.</param>
/// <param name="byState">The initial tool bar button state.</param>
/// <param name="byStyle">The tool bar button style.</param>
/// <param name="wszText">The optional text to display below the image.</param>
/// <param name="bPrependSeparator">The flag determining whether to prepend a separator.
/// </param>
/// <returns>The number of remaining image list slots for tool bar button images.</returns>
/// <remarks>Can still be called like this to create an not-prepended separator
/// (but the space isn't correct):
/// pToolBar->AddButton(NULL, NULL, (UINT)0, TBSTATE_ENABLED, TBSTYLE_SEP);</remarks>
UINT OgwwToolBar::AddButton(HBITMAP hBmpImage, HBITMAP hBmpMask, 
                            UINT uiCommandID, BYTE byState,
                            BYTE byStyle, LPCWSTR wszText, BOOL bPrependSeparator)
{
    if (hBmpImage != NULL)
    {
        ::ImageList_Add(_hImageList, hBmpImage, hBmpMask);
        _wBitmapUsed++;
    }

    if (bPrependSeparator != FALSE)
    {
        TBBUTTON tbb[2];
        ::ZeroMemory(tbb, sizeof(tbb));

        tbb[0].iBitmap   = 0;
        tbb[0].idCommand = 0;
        tbb[0].fsState   = TBSTATE_ENABLED;
        tbb[0].fsStyle   = TBSTYLE_SEP;
        tbb[0].iString   = 0;

        tbb[1].iBitmap   = (_hImageList != NULL) ? _wBitmapUsed - 1 : 0;
        tbb[1].idCommand = uiCommandID;
        tbb[1].fsState   = byState;
        tbb[1].fsStyle   = byStyle;
        tbb[1].iString   = 0; // SendMessageW(hToolBar, TB_ADDSTRING, 0, (LPARAM)wszText);

        // Try this if it doesn't work out right away:
        //::SendMessageW((HWND)_hHandle, TB_BUTTONSTRUCTSIZE, (WPARAM)sizeof(TBBUTTON), 0);
        ::SendMessageW((HWND)_hHandle, TB_ADDBUTTONS, 2, (LPARAM)tbb);
    }
    else
    {
        TBBUTTON tbb;
        ::ZeroMemory(&tbb, sizeof(tbb));

        tbb.iBitmap   = (_hImageList != NULL) ? _wBitmapUsed - 1 : 0;
        tbb.idCommand = uiCommandID;
        tbb.fsState   = byState;
        tbb.fsStyle   = byStyle;
        tbb.iString   = 0; // SendMessageW(hToolBar, TB_ADDSTRING, 0, (LPARAM)wszText);

        ::SendMessageW((HWND)_hHandle, TB_ADDBUTTONS, 1, (LPARAM)&tbb);
    }

    return (_wBitmapCount - _wBitmapUsed);
}

编程愉快！

关注点

并非所有允许/编译通过的代码都能正常工作。

历史

• 2020 年 1 月 16 日：初始版本