# 独立滚动条控件 ## 1.1 滚动条的定义 - 滚动条控件的组成部分有箭头(arrow)、滚槽(shaft)、游标(thumb)三部分组成。有的滚动条没有箭头，有的没有滚槽和游标。如图: __图 1.1__ 滚动条结构图 ![滚动条结构图](figures/Part4Chapter21-1.1.gif) - 滚动条是矩形的，当鼠标击中滚动条，滚动条发送消息给父窗口，父窗口显示更新的窗口内容并更新游标的位置。当鼠标点击箭头时，滚动条也会发消息给父窗口，更新父窗口的内容和游标的位置。 ## 1.2 滚动条的形态 滚动条有两种形态：一种是以主窗口或者其他控件的一部分出现，通过风格 `WS_HSCROLL`、`WS_VSCROLL` 来指定是否拥有水平、垂直滚动条。主窗口或者控件可以同时拥有这两种风格；另一种是独立控件，控件类名是 `CTRL_SCROLLBAR`，应用程序在创建滚动条控件时，通过 `SBS_HORZ` 或者 `SBS_VERT` 来确定是创建水平滚动条还是垂直滚动条，这两种风格只能选择其一。前者不是本章要介绍的内容，但是毕竟二者有密切的联系，因此，此处作一下必要的介绍。 ## 1.3 独立滚动条的风格 独立滚动条拥有如下的风格： __表 1.1__ 独立滚动条风格 | 风格标识符 | 意义 | |:---------------------|:-------| |`SBS_HORZ` | 创建一个水平滚动条。当没有指定 `SBS_BOTTOMALIGN` 或 `SBS_TOPALIGN`，滚动条的范围根据 `CreateWindowEx2` 参数 x,y,w,h 决定。 | |`SBS_VERT` | 创建一个垂直滚动条。当没有指定 `SBS_LEFTALIGN` 或 `SBS_RIGHTALIGN`，滚动条的范围根据 `CreateWindowEx2` 参数 x,y,w,h 决定。 | |`SBS_BOTTOMALIGN` | 与 `SBS_HORZ` 一起使用。放置水平滚动条在 `CreateWindowEx2` 指定范围的底部。| |`SBS_TOPALIGN` | 与 `SBS_HORZ` 一起使用。放置水平滚动条在 `CreateWindowEx2` 指定范围的顶部。 | |`SBS_LEFTALIGN` | 与 `SBS_VERT` 一起使用。放置垂直滚动条在 `CreateWindowEx2` 指定范围的左边。| |`SBS_RIGHTALIGN` | 与 `SBS_VERT` 一起使用，放置垂直滚动条在 `CreateWindowEx2` 指定范围的右边。| |`SBS_NOARROWS` | 没有箭头，不能与 `SBS_NOSHAFT` 一起使用 | |`SBS_NOSHAFT` | 没有 `shaft`，不能与 `SBS_NOARROWS` 一起使用 | |`SBS_FIXEDBARLEN` | 水平滚动条的 `thumb` 长度固定，或者垂直滚动条的 `thumb` 长度固定 | |`SBS_NOTNOTIFYPARENT` | 向父窗口的通知发送方式不是发送通知码，而是发送消息；默认发送通知码 | ## 1.4 独立滚动条的消息 应用程序可以向滚动条控件发送下面的消息来进行相应的处理： - 获取/设置滚动条的数据信息：`SBM_GETSCROLLINFO`、`SBM_SETSCROLLINFO` - 获取/设置当前 `thumb` 的位置： `SBM_GETPOS` 、 `SBM_SETPOS` - 获取/设置滚动范围 `range`： `SBM_GETRANGE` 、 `SBM_SETRANGE` - 设置滚动范围 `range` 并且立即重绘： `SBM_SETRANGEREDRAW` - 启用/禁止箭头 `arrow`: `SBM_ENABLE_ARROW` ### 1.4.1 获取滚动条信息 应用程序向滚动条发送 `wParam` 参数为 `SCROLLINFO` *指针的 `SBM_GETSCROLLINFO` 消息获取滚动条控件的最大值、最小值、滚动条所含的页数、当前位置这些信息。所获取到的信息将存放在 `wParam` 所指向的内存里面返回。`SCROLLINFO` 结构体如下： ```c /* * Scroll bar information structure. */ typedef struct _SCROLLINFO { /** Size of the structrue in bytes */ UINT cbSize; /** * A flag indicates which fields contain valid values, * can be OR'ed value of the following values: * - SIF_RANGE\n * Retrives or sets the range of the scroll bar. * - SIF_PAGE\n * Retrives or sets the page size of the scroll bar. * - SIF_POS\n * Retrives or sets the position of the scroll bar. * - SIF_DISABLENOSCROLL\n * Hides the scroll when disabled, not implemented so far. */ UINT fMask; /** The minimum position value of the scroll bar */ int nMin; /** The maximum position value of the scroll bar */ int nMax; /** The page size of the scroll bar */ UINT nPage; /** The position value of the scroll bar */ int nPos; } SCROLLINFO, *PSCROLLINFO; ``` 通过 `SBM_GETSCROLLINFO` 消息所能获得的信息是由 `SBM_GETSCROLLINFO` 结构体的fMask 来指定的，`fMas` 可取如下表的值： __表 1.2__ 滚动条信息列表 | 信息标识符 | 意义 | |:-----------|:------| |`SIF_RANGE` | 获取滚动条的取值范围| |`SIF_PAGE` | 获取滚动条的页数| |`SIF_POS` | 获取滚动条的当前位置| |`SIF_ALL` | 获取上面所有的信息| 下面的示例是获取滚动条控件的所有信息 ```c SCROLLINFO scinfo = {0}; scinfo.fMask = SIF_ALL; SendMessage (hwnd_scrollbar, SBM_GETSCROLLINFO, (wParam)&scinfo, 0); ``` ### 1.4.2 设置滚动条信息 向滚动条控件发送 `SBM_SETSCROLLINFO` 消息进行滚动条信息设置。参数 `wParam` 为 `SCROLLINFO` 结构体指针，存放有需要设置的滚动条信息。参数 `lParam` 用来确定是否立即重绘，`FALSE` 为不重绘, `TRUE` 则立即重绘。 下面的示例是对滚动条的信息进行设置，并且不立即进行重绘： ```c SCROLLINFO scinfo = {0}; scinfo.fMask = SIF_ALL; scinfo.nMin = 0; scinfo.nMax = 10; scinfo.nPage = 2; scinfo.nPos = 0; BOOL redraw = FALSE; SendMessage (hwnd_scrollbar, SBM_SETCROLLINFO, (wParam)&scinfo, redraw); ``` ### 1.4.3 获取当前游标的位置 向滚动条发送 `SBM_GETPOS` 消息，就可以获取当前游标所在位置。下面是示例代码： ```c int pos = SendMessage (hwnd_scrollbar, SBM_GETPOS, 0, 0); ``` ### 1.4.4 设置当前游标的位置 向滚动条发送 `SBM_SETPOS` 消息，设置滚动条游标当前的位置。目的位置放在参数 `wParam` 中， `lParam` 表示是否立即重绘，`TRUE` 立即重绘，`FALSE` 不重绘。 ```c int pos = 10; SendMessage (hwnd_scrollbar, SBM_SETPOS, pos, TRUE); ``` ### 1.4.5 获取滚动条滚动范围 通过 `SBM_GETRANGE` 消息可以获取滚动条的滚动范围。参数 `wParam` 得到最小范围，`lParam` 得到最大范围。 ```c int min, max; SendMessage (hwnd_scrollbar, SBM_GETRANGE, &min, &max); ``` ### 1.4.6 设置滚动条滚动范围 通过 `SBM_SETRANGE` 消息可以设置滚动条的滚动范围。参数 `wParam` 是设置的最小范围，`lParam` 是设置的最大范围，此消息不会引起滚动条立即重绘。 下面的代码设置滚动条的滚动范围在 0 至 100 之间，但是需要在别的消息或者事件引起界面重绘时，你才能看到滚动条的变化。 ```c SendMessage (hwnd_scrollbar, SBM_SETRANGE, 0, 100); ``` ### 1.4.7 设置滚动条滚动范围，并立即重绘 如果需要设置滚动条滚动范围并且要立即重绘的话，则需要向它发送 `SBM_SETRANGEREDRAW` 消息。参数 `wParam` 是设置的最小范围，`lParam` 是设置的最大范围。 下面的代码设置滚动条的滚动范围在 0 至 100 之间，并且立即重绘。 ```c SendMessage (hwnd_scrollbar, SBM_SETRANGEREDRAW, 0, 100); ``` ### 1.4.8 启用或者禁用滚动条箭头 通过 `SBM_ENABLE_ARROW` 消息可以启用或者禁止滚动条箭头。所谓禁止就是不能向箭头指向的方向滚动。参数 `wParam` 可以取值如下，`lParam` 为 `TRUE` 表示启用，`FALSE` 表示禁用。 __表 1.3__ 箭头标识表 | 箭头标识符 | 意义 | |:---------------|:------| |`SB_ARROW_LTUP` | 代表水平滚动条的左方向键或者垂直滚动条的上方向键 | |`SB_ARROW_BTDN` | 代表水平滚动条的右方向键或者垂直滚动条的下方向键 | |`SB_ARROW_BOTH` | 所有方向键 | 下面的代码将禁用滚动条所有的箭头 ```c SendMessage (hwnd_scrollbar, SBM_ENABLE_ARROW, SB_ARROW_BOTH, FALSE); ``` ## 1.5 滚动条可配置的属性 滚动条有如下的属性可以通过 `GetWindowElementAttr`、`SetWindowElementAttr`、`GetWindowElementPixelEx`、`SetWindowElementPixelEx` 这些函数来获取与设置。下表是可配置的属性列表及说明： __表 1.4__ 通知码列表 | 属性标识符 | 说明 | |:----------------------|:-----| |`WE_MAINC_THREED_BODY` | 绘制滚动条滚槽的颜色以及游标的颜色 | |`WE_FGC_THREED_BODY` | 绘制箭头的颜色 | |`WE_FGC_DISABLED_ITEM` | 绘制无效箭头的颜色 | |`WE_METRICS_SCROLLBAR` | 滚动条的尺寸，即水平滚动条的高度、垂直滚动条的宽度 | 下面的代码演示了对上面属性的操作： ```c DWORD color_3d, fgc_3d, fgc_dis; gal_pixel old_brush_color; //获取绘制滚动条各个部分的颜色属性值 color_3d = GetWindowElementAttr(hWnd, WE_MAINC_THREED_BODY); fgc_3d = GetWindowElementAttr(hWnd, WE_FGC_THREED_BODY); fgc_dis = GetWindowElementAttr(hWnd, WE_FGC_DISABLED_ITEM); //绘制滚动条滚槽 old_brush_color = SetBrushColor(hdc, RGBA2Pixel(hdc,GetRValue(color_3d), GetGValue(color_3d), GetBValue(color_3d), GetAValue(color_3d))); FillBox(hdc, rect.left, rect.top, RECTW(rect), RECTH(rect)); SetBrushColor(hdc, old_brush_color); //绘制滚动条箭头 draw_3dbox(hdc, &rect, color_3d, bn_status | LFRDR_3DBOX_THICKFRAME | LFRDR_3DBOX_FILLED); if(sb_status & SBS_DISABLED_LTUP || sb_status & SBS_DISABLED) draw_arrow(hWnd, hdc, &rect, fgc_dis, LFRDR_ARROW_LEFT); else draw_arrow(hWnd, hdc, &rect, fgc_3d, LFRDR_ARROW_LEFT); ``` ## 1.6 滚动条通知码 滚动条所拥有的通知码如下表： __表 1.5__ 通知码列表 | 通知码标识符 | 意义 | |:------------------|:----| |`SB_LINEUP` | 垂直滚动条向上滚一行 | |`SB_LINEDOWN` | 垂直滚动条向下滚一行 | |`SB_PAGEUP` | 垂直滚动条向上滚一页 | |`SB_PAGEDOWN` | 垂直滚动条向下滚一页 | |`SB_LINELEFT` | 水平滚动条向左滚一列 | |`SB_LINERIGHT` | 水平滚动条向右滚一列 | |`SB_PAGELEFT` | 水平滚动条向左滚一列页 | |`SB_PAGERIGHT` | 水平滚动条向右滚一页 | |`SB_THUMBPOSITION` | 当游标被鼠标左键按住拖动，然后释放，此时的游标位置将由此通知码传给父窗口 | |`SB_THUMBTRACK` | 当游标被鼠标左键按住，在拖动游标的过程中，游标的位置将由此通知码不断的传给父窗口 | |`SB_TOP` | 游标到了水平滚动条的最左边或者是垂直滚动条的最上边，即到了滚动条的最小值 | |`SB_BOTTOM` | 游标到了水平滚动条的最右边或者是垂直滚动条的最下边，即到了滚动条的最大值| - 当滚动条指定了风格 `SBS_NOTNOTIFYPARENT` 时，水平滚动条的父窗口将会收到 `MSG_HSCROLL` 消息，垂直滚动条的父窗口将会收到 `MSG_VSCROLL` 消息， 参数 `wParam` 为通知码 `id`， 当 `id` 为 `SB_THUMBPOSITION`,`SB_THUMBTRACK` 时，`lParam` 为游标的当前位置 `curPos`，其他情况下 `lParam` 没有意义。 - 当滚动条没有指定风格 `SBS_NOTNOTIFYPARENT` 时，滚动条的父窗口将会收到通知码，参数 `wParam` 包含控件 `ID` 和通知码。当通知码为 `SB_THUMBPOSITION`,`SB_THUMBTRACK` 时，父窗口可以通过发送 `SBM_GETPOS` 来获取游标的当前位置 `curPos`。当然，如果你调用 `SetNotificationCallback` 函数设定了滚动条控件的通知回调函数，则控件不会向父窗口发送 `MSG_COMMAND `通知消息，而是会直接调用设定的通知回调函数。 ### 1.6.1 通知消息的触发 滚动条可以接收鼠标和键盘事件，并根据不同的情况触发不同的通知消息。 - 当鼠标点击滚动条不同部位时，会触发不同的通知消息。另外，要注意的是，用鼠标左键拖动游标的过程中，滚动条会不断发送 `SB_THUMBTRACK` 通知消息，鼠标左键释放后会发送 `SB_THUMBPOSITIO` 消息。滚动条各个部位所触发的消息，请见下图： __图 1.2__ 鼠标触发的通知消息 ![鼠标触发的通知消息](figures/Part4Chapter21-1.2.gif) - 键盘按键会触发相应的通知消息，具体如下表所示： __表 1.6__ 通知码列表 | 按键 | 通知码 | |:-------------|:------| |`PAGEUP` 键 | 水平滚动条发送 `SB_PAGELEFT` ；垂直滚动条发送 `SB_PAGEUP` | |`PAGEDOWN` 键 | 水平滚动条发送 `SB_PAGERIGHT` ；垂直滚动条发送 `SB_PAGEDOWN` | |上方向键 | 垂直滚动条发送 `SB_LINEUP` | |左方向键 | 水平滚动条发送 `SB_LINELEFT` | |下方向键 | 垂直滚动条发送 `SB_LINEDOWN` | |右方向键 | 水平滚动条发送 `SB_LINERIGHT` | |`HOME` 键 | `SB_TOP` | |`END` 键 | `SB_BOTTOM` | ## 1.7 编程示例 下面的代码给出了各种样式的滚动条的创建示例。通过鼠标或者按键，你可以对滚动条进行点击、拖动等操作。为了使演示更生动，本示例还在界面的右边放置了一个圆圈和方块，随着你控制滚动条上下或者左右滚动，圆圈会变大变小，方块会上下移动。示例的效果如__图 1.3__ 所示，代码摘自示例程序包 `mg-samples` 中的 `scrollbar_ctrl.c` 文件，完整代码请见此文件。 __清单 1.1__ 滚动条示例代码 ```c #include #include #include #include #include #include #include #ifdef _LANG_ZHCN #include "scrollbar_ctrl_res_cn.h" #elif defined _LANG_ZHTW #include "scrollbar_ctrl_res_tw.h" #else #include "scrollbar_ctrl_res_en.h" #endif /** define scrollbar data */ #define SB_MAX 20 #define SB_MIN 0 #define SB_PAGE 6 /** define circle data */ #define CC_CENTER_X 400 #define CC_CENTER_Y 100 #define CC_RADIUS_MAX 50 #define CC_RADIUS_MIN 0 /** define box data */ #define BOX_WIDTH 40 #define BOX_HEIGHT 20 #define BOX_Y_MAX 300 #define BOX_Y_MIN 200 /** x position of separator */ #define SEP 300 /** radius of circle */ int _radius; /** y position of box */ int _box_pos_y; /** invalidate rect */ RECT _rect_invalid; static int ScrollbarProc(HWND hwnd, int message, WPARAM wParam, LPARAM lParam) { /** IDC of SCROLLBAR control */ static int _my_scroll_idc = 100; /** scrollbar handle of main window */ static HWND hwnd_sb_main; /** scrollbar handle of control */ HWND hwnd_sb_ctrl; switch (message) { case MSG_CREATE: { _rect_invalid.left = SEP; _rect_invalid.top = 0; _rect_invalid.right = g_rcScr.right; _rect_invalid.bottom = g_rcScr.bottom; SCROLLINFO scinfo = {0}; scinfo.fMask = SIF_ALL; scinfo.nMin = SB_MIN; scinfo.nMax = SB_MAX; scinfo.nPage = SB_PAGE; scinfo.nPos = SB_MIN; calc_circle_pos (scinfo.nPos); calc_box_pos (scinfo.nPos); /** classic VSCROLL with SBS_NOTNOTIFYPARENT */ hwnd_sb_main = CreateWindowEx2 (CTRL_SCROLLBAR, "", WS_VISIBLE | SBS_VERT | SBS_LEFTALIGN | SBS_NOTNOTIFYPARENT , 0, ++_my_scroll_idc, 20, 50, 20, 150, hwnd, "classic", 0, 0); SendMessage (hwnd_sb_main, SBM_SETSCROLLINFO, (WPARAM)&scinfo, TRUE); SendMessage (hwnd_sb_main, MSG_SETFOCUS, 0, 0); /** flat VSCROLL */ hwnd_sb_ctrl = CreateWindowEx2 (CTRL_SCROLLBAR, "", WS_VISIBLE | SBS_VERT | SBS_LEFTALIGN , 0, ++_my_scroll_idc, 43, 50, 20, 150, hwnd, "flat", 0, 0); SendMessage (hwnd_sb_ctrl, SBM_SETSCROLLINFO, (WPARAM)&scinfo, TRUE); SendMessage (hwnd_sb_ctrl, MSG_SETFOCUS, 0, 0); /** fashion VSCROLL */ hwnd_sb_ctrl = CreateWindowEx2 (CTRL_SCROLLBAR, "", WS_VISIBLE | SBS_VERT | SBS_LEFTALIGN , 0, ++_my_scroll_idc, 66, 50, 20, 150, hwnd, "fashion", 0, 0); SendMessage (hwnd_sb_ctrl, SBM_SETSCROLLINFO, (WPARAM)&scinfo, TRUE); SendMessage (hwnd_sb_ctrl, MSG_SETFOCUS, 0, 0); /** tiny VSCROLL */ hwnd_sb_ctrl = CreateWindowEx2 (CTRL_SCROLLBAR, "", WS_VISIBLE | SBS_VERT | SBS_LEFTALIGN , 0, ++_my_scroll_idc, 92, 50, 20, 150, hwnd, "tiny", 0, 0); SendMessage (hwnd_sb_ctrl, SBM_SETSCROLLINFO, (WPARAM)&scinfo, TRUE); SendMessage (hwnd_sb_ctrl, MSG_SETFOCUS, 0, 0); /** classic NOSHAFT VSCROLL */ hwnd_sb_ctrl = CreateWindowEx2 (CTRL_SCROLLBAR, "", WS_VISIBLE | SBS_VERT | SBS_NOSHAFT | SBS_LEFTALIGN , 0, ++_my_scroll_idc, 120, 50, 20, 34, hwnd, "classic", 0, 0); SendMessage (hwnd_sb_ctrl, SBM_SETSCROLLINFO, (WPARAM)&scinfo, TRUE); SendMessage (hwnd_sb_ctrl, MSG_SETFOCUS, 0, 0); /** flat NOSHAFT VSCROLL */ hwnd_sb_ctrl = CreateWindowEx2 (CTRL_SCROLLBAR, "", WS_VISIBLE | SBS_VERT | SBS_NOSHAFT | SBS_LEFTALIGN , 0, ++_my_scroll_idc, 140, 50, 20, 34, hwnd, "flat", 0, 0); SendMessage (hwnd_sb_ctrl, SBM_SETSCROLLINFO, (WPARAM)&scinfo, TRUE); SendMessage (hwnd_sb_ctrl, MSG_SETFOCUS, 0, 0); /** fashion NOSHAFT VSCROLL */ hwnd_sb_ctrl = CreateWindowEx2 (CTRL_SCROLLBAR, "", WS_VISIBLE | SBS_VERT | SBS_NOSHAFT | SBS_LEFTALIGN , 0, ++_my_scroll_idc, 160, 50, 20, 34, hwnd, "fashion", 0, 0); SendMessage (hwnd_sb_ctrl, SBM_SETSCROLLINFO, (WPARAM)&scinfo, TRUE); SendMessage (hwnd_sb_ctrl, MSG_SETFOCUS, 0, 0); /** tiny NOSHAFT VSCROLL */ hwnd_sb_ctrl = CreateWindowEx2 (CTRL_SCROLLBAR, "", WS_VISIBLE | SBS_VERT | SBS_NOSHAFT | SBS_LEFTALIGN , 0, ++_my_scroll_idc, 184, 50, 20, 34, hwnd, "tiny", 0, 0); SendMessage (hwnd_sb_ctrl, SBM_SETSCROLLINFO, (WPARAM)&scinfo, TRUE); SendMessage (hwnd_sb_ctrl, MSG_SETFOCUS, 0, 0); /** classic NOARROW VSCROLL */ hwnd_sb_ctrl = CreateWindowEx2 (CTRL_SCROLLBAR, "", WS_VISIBLE | SBS_VERT | SBS_NOARROW | SBS_LEFTALIGN , 0, ++_my_scroll_idc, 210, 50, 20, 150, hwnd, "classic", 0, 0); SendMessage (hwnd_sb_ctrl, SBM_SETSCROLLINFO, (WPARAM)&scinfo, TRUE); SendMessage (hwnd_sb_ctrl, MSG_SETFOCUS, 0, 0); /** flat NOARROW VSCROLL */ hwnd_sb_ctrl = CreateWindowEx2 (CTRL_SCROLLBAR, "", WS_VISIBLE | SBS_VERT | SBS_NOARROW | SBS_LEFTALIGN , 0, ++_my_scroll_idc, 232, 50, 20, 150, hwnd, "flat", 0, 0); SendMessage (hwnd_sb_ctrl, SBM_SETSCROLLINFO, (WPARAM)&scinfo, TRUE); SendMessage (hwnd_sb_ctrl, MSG_SETFOCUS, 0, 0); /** fashion NOARROW VSCROLL */ hwnd_sb_ctrl = CreateWindowEx2 (CTRL_SCROLLBAR, "", WS_VISIBLE | SBS_VERT | SBS_NOARROW | SBS_LEFTALIGN , 0, ++_my_scroll_idc, 254, 50, 20, 150, hwnd, "fashion", 0, 0); SendMessage (hwnd_sb_ctrl, SBM_SETSCROLLINFO, (WPARAM)&scinfo, TRUE); SendMessage (hwnd_sb_ctrl, MSG_SETFOCUS, 0, 0); /** tiny NOARROW VSCROLL */ hwnd_sb_ctrl = CreateWindowEx2 (CTRL_SCROLLBAR, "", WS_VISIBLE | SBS_VERT | SBS_NOARROW | SBS_LEFTALIGN , 0, ++_my_scroll_idc, 276, 50, 20, 150, hwnd, "tiny", 0, 0); SendMessage (hwnd_sb_ctrl, SBM_SETSCROLLINFO, (WPARAM)&scinfo, TRUE); SendMessage (hwnd_sb_ctrl, MSG_SETFOCUS, 0, 0); /** classic HSCROLL */ hwnd_sb_ctrl = CreateWindowEx2 (CTRL_SCROLLBAR, "", WS_VISIBLE | SBS_HORZ | SBS_TOPALIGN , 0, ++_my_scroll_idc, 20, 220, 150, 20, hwnd, "classic", 0, 0); SendMessage (hwnd_sb_ctrl, SBM_SETSCROLLINFO, (WPARAM)&scinfo, TRUE); SendMessage (hwnd_sb_ctrl, MSG_SETFOCUS, 0, 0); /** flat HSCROLL */ hwnd_sb_ctrl = CreateWindowEx2 (CTRL_SCROLLBAR, "", WS_VISIBLE | SBS_HORZ | SBS_TOPALIGN , 0, ++_my_scroll_idc, 20, 240, 150, 20, hwnd, "flat", 0, 0); SendMessage (hwnd_sb_ctrl, SBM_SETSCROLLINFO, (WPARAM)&scinfo, TRUE); SendMessage (hwnd_sb_ctrl, MSG_SETFOCUS, 0, 0); /** fashion HSCROLL */ hwnd_sb_ctrl = CreateWindowEx2 (CTRL_SCROLLBAR, "", WS_VISIBLE | SBS_HORZ | SBS_TOPALIGN , 0, ++_my_scroll_idc, 20, 260, 150, 20, hwnd, "fashion", 0, 0); SendMessage (hwnd_sb_ctrl, SBM_SETSCROLLINFO, (WPARAM)&scinfo, TRUE); SendMessage (hwnd_sb_ctrl, MSG_SETFOCUS, 0, 0); /** tiny HSCROLL */ hwnd_sb_ctrl = CreateWindowEx2 (CTRL_SCROLLBAR, "", WS_VISIBLE | SBS_HORZ | SBS_TOPALIGN , 0, ++_my_scroll_idc, 20, 280, 150, 20, hwnd, "tiny", 0, 0); SendMessage (hwnd_sb_ctrl, SBM_SETSCROLLINFO, (WPARAM)&scinfo, TRUE); SendMessage (hwnd_sb_ctrl, MSG_SETFOCUS, 0, 0); } break; case MSG_COMMAND: { int code = HIWORD(wParam); HWND scroll = (HWND)lParam; int pos = 0; switch (code) { case SB_LINELEFT: { pos = SendMessage (scroll, SBM_GETPOS, 0, 0); SendMessage (scroll, SBM_SETPOS, --pos, TRUE); } break; case SB_LINERIGHT: { pos = SendMessage (scroll, SBM_GETPOS, 0, 0); SendMessage (scroll, SBM_SETPOS, ++pos, TRUE); } break; case SB_PAGELEFT: { pos = SendMessage (scroll, SBM_GETPOS, 0, 0); pos -= SB_PAGE; SendMessage (scroll, SBM_SETPOS, pos, TRUE); } break; case SB_PAGERIGHT: { pos = SendMessage (scroll, SBM_GETPOS, 0, 0); pos += SB_PAGE; SendMessage (scroll, SBM_SETPOS, pos, TRUE); } break; case SB_LINEUP: { pos = SendMessage (scroll, SBM_GETPOS, 0, 0); SendMessage (scroll, SBM_SETPOS, --pos, TRUE); } break; case SB_LINEDOWN: { pos = SendMessage (scroll, SBM_GETPOS, 0, 0); SendMessage (scroll, SBM_SETPOS, ++pos, TRUE); } break; case SB_PAGEUP: { pos = SendMessage (scroll, SBM_GETPOS, 0, 0); pos -= SB_PAGE; SendMessage (scroll, SBM_SETPOS, pos, TRUE); } break; case SB_PAGEDOWN: { pos = SendMessage (scroll, SBM_GETPOS, 0, 0); pos += SB_PAGE; SendMessage (scroll, SBM_SETPOS, pos, TRUE); } break; case SB_THUMBPOSITION: { pos = SendMessage (scroll, SBM_GETPOS, 0, 0); } break; case SB_THUMBTRACK: { pos = SendMessage (scroll, SBM_GETPOS, 0, 0); } break; case SB_TOP: { pos = SB_MIN; } break; case SB_BOTTOM: { pos = SB_MAX; } break; default: break; } draw_shape (hwnd, pos); } break; case MSG_HSCROLL: { int pos = 0; switch (wParam) { case SB_LINELEFT: { pos = SendMessage (hwnd_sb_main, SBM_GETPOS, 0, 0); SendMessage (hwnd_sb_main, SBM_SETPOS, --pos, TRUE); } break; case SB_LINERIGHT: { pos = SendMessage (hwnd_sb_main, SBM_GETPOS, 0, 0); SendMessage (hwnd_sb_main, SBM_SETPOS, ++pos, TRUE); } break; case SB_PAGELEFT: { pos = SendMessage (hwnd_sb_main, SBM_GETPOS, 0, 0); pos -= SB_PAGE; SendMessage (hwnd_sb_main, SBM_SETPOS, pos, TRUE); } break; case SB_PAGERIGHT: { pos = SendMessage (hwnd_sb_main, SBM_GETPOS, 0, 0); pos += SB_PAGE; SendMessage (hwnd_sb_main, SBM_SETPOS, pos, TRUE); } break; case SB_THUMBPOSITION: { pos = (int)lParam; } break; case SB_THUMBTRACK: { pos = (int)lParam; } break; case SB_TOP: { pos = SB_MIN; } break; case SB_BOTTOM: { pos = SB_MAX; } break; default: break; } draw_shape (hwnd, pos); } break; case MSG_VSCROLL: { int pos = 0; switch (wParam) { case SB_LINEUP: { pos = SendMessage (hwnd_sb_main, SBM_GETPOS, 0, 0); SendMessage (hwnd_sb_main, SBM_SETPOS, --pos, TRUE); } break; case SB_LINEDOWN: { pos = SendMessage (hwnd_sb_main, SBM_GETPOS, 0, 0); SendMessage (hwnd_sb_main, SBM_SETPOS, ++pos, TRUE); } break; case SB_PAGEUP: { pos = SendMessage (hwnd_sb_main, SBM_GETPOS, 0, 0); pos -= SB_PAGE; SendMessage (hwnd_sb_main, SBM_SETPOS, pos, TRUE); } break; case SB_PAGEDOWN: { pos = SendMessage (hwnd_sb_main, SBM_GETPOS, 0, 0); pos += SB_PAGE; SendMessage (hwnd_sb_main, SBM_SETPOS, pos, TRUE); } break; case SB_THUMBPOSITION: { pos = (int)lParam; } break; case SB_THUMBTRACK: { pos = (int)lParam; } break; case SB_TOP: { pos = SB_MIN; } break; case SB_BOTTOM: { pos = SB_MAX; } break; default: break; } draw_shape (hwnd, pos); } break; case MSG_PAINT: { HDC hdc = BeginPaint(hwnd); /** separator */ MoveTo (hdc, SEP, 0); LineTo (hdc, SEP, g_rcScr.bottom); /** circle */ Circle (hdc, CC_CENTER_X, CC_CENTER_Y, _radius); /** top and bottom line of box */ MoveTo (hdc, SEP + 20, BOX_Y_MIN); LineTo (hdc, SEP + 20 + BOX_WIDTH + 40, BOX_Y_MIN); MoveTo (hdc, SEP + 20, BOX_Y_MAX); LineTo (hdc, SEP + 20 + BOX_WIDTH + 40, BOX_Y_MAX); /** box */ SetBrushColor (hdc, PIXEL_black); FillBox (hdc, SEP + 40, _box_pos_y, BOX_WIDTH, BOX_HEIGHT); EndPaint (hwnd, hdc); } break; case MSG_CLOSE: { DestroyMainWindow (hwnd); PostQuitMessage (hwnd); return 0; } } return DefaultMainWinProc(hwnd, message, wParam, lParam); } int MiniGUIMain (int argc, const char* argv[]) { MSG Msg; HWND hMainWnd; MAINWINCREATE CreateInfo; #ifdef _MGRM_PROCESSES JoinLayer(NAME_DEF_LAYER , "scrollbar" , 0 , 0); #endif CreateInfo.dwStyle = WS_VISIBLE | WS_BORDER | WS_CAPTION; CreateInfo.dwExStyle = WS_EX_NONE; CreateInfo.spCaption = SCB_ST_CAP; CreateInfo.hMenu = 0; CreateInfo.hCursor = GetSystemCursor(0); CreateInfo.hIcon = 0; CreateInfo.MainWindowProc = ScrollbarProc; CreateInfo.lx = 0; CreateInfo.ty = 0; CreateInfo.rx = g_rcScr.right; CreateInfo.by = g_rcScr.bottom; CreateInfo.iBkColor = COLOR_lightwhite; CreateInfo.dwAddData = 0; CreateInfo.hHosting = HWND_DESKTOP; hMainWnd = CreateMainWindowEx (&CreateInfo, "flat", 0, 0, 0); if (hMainWnd == HWND_INVALID) { return -1; } ShowWindow(hMainWnd, SW_SHOWNORMAL); while (GetMessage(&Msg, hMainWnd)) { TranslateMessage(&Msg); DispatchMessage(&Msg); } MainWindowThreadCleanup (hMainWnd); return 0; } #ifdef _MGRM_THREADS #include #endif ``` __图 1.3__ 滚动条控件 ![滚动条控件](figures/Part4Chapter21-1.3.png)