Win32滚动条无法使用。这是我在win32 CC++中的代码
#include <windows.h>
#include <stdio.h>
/* Declare Windows procedure */
LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM);
HWND text, text2, button, mm;
HMENU hmenu;
void AddMenus(HWND);
char textsave[20];
/* Make the class name into a global variable */
char szClassName[ ] ="CodeBlocksWindowsApp";
int WINAPI WinMain (HINSTANCE hThisInstance,
HINSTANCE hPrevInstance,
LPSTR lpszArgument,
int nCmdShow)
{
HWND hwnd; /* This is the handle for our window */
MSG messages; /* Here messages to the application are saved */
WNDCLASSEX wincl; /* Data structure for the windowclass */
/* The Window structure */
wincl.hInstance = hThisInstance;
wincl.lpszClassName = szClassName;
wincl.lpfnWndProc = WindowProcedure; /* This function is called by windows */
wincl.style = CS_DBLCLKS; /* Catch double-clicks */
wincl.cbSize = sizeof (WNDCLASSEX);
/* Use default icon and mouse-pointer */
wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION);
wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
wincl.hCursor = LoadCursor (NULL, IDC_ARROW);
wincl.lpszMenuName = NULL; /* No menu */
wincl.cbClsExtra = 0; /* No extra bytes after the window class */
wincl.cbWndExtra = 0; /* structure or the window instance */
/* Use Windows's default colour as the background of the window */
wincl.hbrBackground = (HBRUSH) COLOR_BACKGROUND;
/* Register the window class, and if it fails quit the program */
if (!RegisterClassEx (&wincl))
return 0;
/* The class is registered, let's create the program*/
hwnd = CreateWindowEx (
0, /* Extended possibilites for variation */
szClassName, /* Classname */
"", /* Title Text */
WS_OVERLAPPEDWINDOW | WS_VSCROLL, /* default window */
CW_USEDEFAULT, /* Windows decides the position */
CW_USEDEFAULT, /* where the window ends up on the screen */
544, /* The programs width */
375, /* and height in pixels */
HWND_DESKTOP, /* The window is a child-window to desktop */
NULL, /* No menu */
hThisInstance, /* Program Instance handler */
NULL /* No Window Creation data */
);
/* Make the window visible on the screen */
ShowWindow (hwnd, nCmdShow);
/* Run the message loop. It will run until GetMessage() returns 0 */
while (GetMessage (&messages, NULL, 0, 0))
{
/* Translate virtual-key messages into character messages */
TranslateMessage(&messages);
/* Send message to WindowProcedure */
DispatchMessage(&messages);
}
/* The program return-value is 0 - The value that PostQuitMessage() gave */
return messages.wParam;
}
/* This function is called by the Windows function DispatchMessage() */
LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
switch (message) /* handle the messages */
{
case WM_CREATE:
CreateWindow("EDIT", "jdslfkjssf\r\n\r\n\r\nflkjsdf\r\nflskdjfkl",
WS_VISIBLE | WS_CHILD | WS_BORDER | ES_MULTILINE | ES_AUTOVSCROLL,
20, 70, 490, 130, hwnd, NULL, NULL, NULL);
CreateWindow("EDIT", "jdslfkjssf\r\n\r\n\r\nflkjsdf\r\nflskdjfkl",
WS_VISIBLE | WS_CHILD | WS_BORDER | ES_MULTILINE | ES_AUTOVSCROLL,
20, 270, 490, 230, hwnd, NULL, NULL, NULL);
break;
case WM_COMMAND:
break;
case WM_DESTROY:
PostQuitMessage (0); /* send a WM_QUIT to the message queue */
break;
default: /* for messages that we don't deal with */
return DefWindowProc (hwnd, message, wParam, lParam);
}
return 0;
}
这里的滚动条不起作用。我想把滚动条往下拉，这样就可以看到底部的其他部分。这个代码怎么写，滚动条能用吗？
如何垂直滚动
1. 获取滚动单位。
滚动单位一般是在处理的时候设置的。WM_CREATE 消息。例如，在你的例子中，你在编辑控件中显示文本，所以这里我们可以把一个字符单元的高度，加上外部前导作为一个垂直滚动单位。要检索一个特定DC的字体尺寸，使用 GetTextMetrics 功能。
2. 处理 WM_SIZE 留言内容
处理时 WM_SIZE 消息，方便调整滚动范围和滚动位置，以反映客户端区域的尺寸。
在 SetScrollInfo 函数设置滚动条的最小和最大位置值、页面大小和滚动位置。
3. 处理 WM_VSCROLL 消息。
当用户点击上方箭头、下方箭头、滚动条轴上方的滚动框、滚动条轴下方的滚动框并拖动滚动框时，滚动条发送 WM_VSCROLL 消息到窗口程序。
当 WM_VSCROLL 消息处理后，检查滚动条请求代码并计算滚动增量。在将增量应用于当前滚动位置后，通过使用该函数将窗口滚动到新的位置。ScrollWindowEx 功能，滚动框的位置可以通过使用 SetScrollInfo 功能。
窗口滚动后，其客户端的部分区域会变成无效区域。为了确保无效区域得到更新，可以使用 UpdateWindow 函数用于生成一个 WM_PAINT 消息。
以下是一个滚动主窗口整个客户端区域的例子，你可以参考。
LRESULT CALLBACK WindowProcedure(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
HDC hdc;
TEXTMETRIC tm;
SCROLLINFO si;
// These variables are required to display text.
static int xClient; // width of client area
static int yClient; // height of client area
static int yChar; // vertical scrolling unit
static int yPos; // current vertical scrolling position
switch (message) /* handle the messages */
{
case WM_CREATE:
{
editCtl1 = CreateWindow("EDIT", "jdslfkjssf\r\n\r\n\r\nflkjsdf\r\nflskdjfkl",
WS_VISIBLE | WS_CHILD | WS_BORDER | ES_MULTILINE | ES_AUTOVSCROLL,
20, 70, 490, 130, hwnd, NULL, NULL, NULL);
editCtl2 = CreateWindow("EDIT", "jdslfkjssf\r\n\r\n\r\nflkjsdf\r\nflskdjfkl",
WS_VISIBLE | WS_CHILD | WS_BORDER | ES_MULTILINE | ES_AUTOVSCROLL,
20, 270, 490, 230, hwnd, NULL, NULL, NULL);
// Get the handle to the client area's device context.
hdc = GetDC(hwnd);
// Extract font dimensions from the text metrics.
GetTextMetrics(hdc, &tm);
yChar = tm.tmHeight + tm.tmExternalLeading;
// Free the device context.
ReleaseDC(hwnd, hdc);
break;
}
case WM_SIZE:
{
// Retrieve the dimensions of the client area.
yClient = HIWORD(lParam);
xClient = LOWORD(lParam);
// Get y-coordinate (bottom) of the second edit control
RECT editCtl2Rect = { 0 };
GetWindowRect(editCtl2, &editCtl2Rect);
POINT point = { 0 };
point.x = editCtl2Rect.right;
point.y = editCtl2Rect.bottom;
// Convert screen coordinate to parent client-area coordinates
ScreenToClient(hwnd, &point);
// Set the vertical scrolling range and page size
si.cbSize = sizeof(si);
si.fMask = SIF_RANGE | SIF_PAGE;
si.nMin = 0;
si.nMax = point.y / yChar;
si.nPage = yClient / yChar;
SetScrollInfo(hwnd, SB_VERT, &si, TRUE);
break;
}
case WM_VSCROLL:
{
// Get all the vertial scroll bar information.
si.cbSize = sizeof(si);
si.fMask = SIF_ALL;
GetScrollInfo(hwnd, SB_VERT, &si);
// Save the position for comparison later on.
yPos = si.nPos;
switch (LOWORD(wParam))
{
// User clicked the top arrow.
case SB_LINEUP:
si.nPos -= 1;
break;
// User clicked the bottom arrow.
case SB_LINEDOWN:
si.nPos += 1;
break;
// User clicked the scroll bar shaft above the scroll box.
case SB_PAGEUP:
si.nPos -= si.nPage;
break;
// User clicked the scroll bar shaft below the scroll box.
case SB_PAGEDOWN:
si.nPos += si.nPage;
break;
// User dragged the scroll box.
case SB_THUMBTRACK:
si.nPos = si.nTrackPos;
break;
default:
break;
}
// Set the position and then retrieve it. Due to adjustments
// by Windows it may not be the same as the value set.
si.fMask = SIF_POS;
SetScrollInfo(hwnd, SB_VERT, &si, TRUE);
GetScrollInfo(hwnd, SB_VERT, &si);
// If the position has changed, scroll window and update it.
if (si.nPos != yPos)
{
ScrollWindow(hwnd, 0, yChar * (yPos - si.nPos), NULL, NULL);
UpdateWindow(hwnd);
}
return 0;
}
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProc(hwnd, message, wParam, lParam);
}
return 0;
}
参考"使用滚动条"了解更多详细信息。