学习windows编程 day2 之滚动条使用

相关函数：

setscrollrange,setscrollpos,getscrollrange,getscrollpos

使用滚动条时我们需要进行的操作：

1.初始化滚动条范围和位置

在窗口创建时WM_CREATE响应时可以完成

SetScrollRange(hwnd, SB_VERT, , NUMLINES,FALSE);

SetScrollPos(hwnd, SB_VERT, , TRUE);

2.处理窗口过程的滚动条消息

在响应WM_VSCROLL时处理

switch(LOWORD(wParam))

{

   case SB_LINEUP:

         ....

         break;

   case SB_LINEDOWN:

         ....

         break;

   case SB_PAGEUP:

         ....

         break;

   case SB_PAGEDOWN:

         ....

         break;

   case SB_THUMBTRACK:

         ....

         break;

   case SB_THUMBPOSITION:

         ....

         break;

}

注意在wParam参数中的低十六位中可以获取鼠标在滚动条上的动作使用LOWORD(wParam)

当滚动条动作为SB_THUMBPOSITION或SB_THUMBTRACK时，可以在wParam参数中的高十六位中获取位置HIWORD(wParam)

3.更新滑块位置

SetScrollPos(hwnd, SB_VERT, XXX, TRUE);

4.根据滚动条变化更新客户端内容

可以在处理滚动条消息是设置全局参数，在WM_PAINT响应时做出响应更新

为了及时更新客户端内容

可以使用

InvalidateRect(hwnd, NULL, TRUE);

向消息队列中发送消息WM_PAINT，此消息会放在消息队列后面，知道其他消息处理完毕才会响应

或者使用

UpdateWindow(hwnd);

非队列化消息，跳过消息循环机制直接处理更新窗口

全部代码：

#include <windows.h>

#include <strsafe.h>

#include "SysMet.h"

LRESULT CALLBACK WndProc(HWND hwnd, UINT message,WPARAM wParam,LPARAM lParam);

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int iShowCmd)

{

    static TCHAR szClassName[] = TEXT("MyWindow5");

    MSG msg;

    HWND hwnd;

    WNDCLASS wndclass;

    wndclass.cbClsExtra=;

    wndclass.cbWndExtra=;

    wndclass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);

    wndclass.hCursor = LoadCursor(NULL, IDI_APPLICATION);

    wndclass.hIcon = LoadIcon(NULL, IDC_ARROW);

    wndclass.hInstance = hInstance;

    wndclass.lpfnWndProc = WndProc;

    wndclass.lpszClassName = szClassName;

    wndclass.lpszMenuName = NULL;

    wndclass.style = CS_HREDRAW;

    if (!RegisterClass(&wndclass))

    {

        MessageBox(NULL, TEXT("this program must run in win nt!"), TEXT("ERROR"), MB_OK);

        return ;

    }

    hwnd = CreateWindow(szClassName,

        TEXT("MyWindowProgram"),

        WS_OVERLAPPEDWINDOW | WS_VSCROLL | WS_HSCROLL,

        CW_USEDEFAULT,

        CW_USEDEFAULT,

        CW_USEDEFAULT,

        CW_USEDEFAULT,

        NULL,

        NULL,

        hInstance,

        NULL

        );

    ShowWindow(hwnd,iShowCmd);

    UpdateWindow(hwnd);

    while (GetMessage(&msg,NULL,,))

    {

        TranslateMessage(&msg);

        DispatchMessage(&msg);

    }

    return msg.wParam;

}

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)

{

    HDC hdc;

    PAINTSTRUCT ps;

    RECT rect;

    TCHAR szBuffer[];

    TEXTMETRIC tm;

    static int cxChar, cyChar, cxCaps,iVscrollPos;//大写占1.5倍

    size_t st;

    int y;

    static int cxClient, cyClient;

    switch (message)

    {

    case WM_CREATE:

        iVscrollPos = ;

        SetScrollRange(hwnd, SB_VERT, , NUMLINES,FALSE);//后面代表是否现在重画窗口

        SetScrollPos(hwnd, SB_VERT, , TRUE);

        hdc = GetDC(hwnd);

        GetTextMetrics(hdc, &tm);

        cxChar = tm.tmAveCharWidth;

        cyChar = tm.tmExternalLeading + tm.tmHeight;

        cxCaps = (tm.tmPitchAndFamily &  ?  : )*cxChar / ;

        ReleaseDC(hwnd,hdc);

        break;

    case WM_SIZE:

        cxClient = LOWORD(lParam);

        cyClient = HIWORD(lParam);

    case WM_PAINT:

        hdc = BeginPaint(hwnd, &ps);

        for (int i = ; i < NUMLINES;i++)

        {

            y = cyChar*(i - iVscrollPos);

            //获取的大量数据

            StringCchLength(sysmetrics[i].szLabel, , &st);

            TextOut(hdc, , y, sysmetrics[i].szLabel, st);

            StringCchLength(sysmetrics[i].szDesc, , &st);

            TextOut(hdc,  * cxCaps, y, sysmetrics[i].szDesc, st);

            SetTextAlign(hdc,TA_RIGHT|TA_TOP);

            StringCchPrintf(szBuffer, , L"%d    %d  %5d", i + ,iVscrollPos, GetSystemMetrics(sysmetrics[i].iIndex));

            StringCchLength(szBuffer, , &st);

            TextOut(hdc,  * cxCaps +  * cxChar, y, szBuffer, st);

            SetTextAlign(hdc, TA_LEFT|TA_TOP);

        }

        //获取屏幕分辨率

//         cxClient=GetSystemMetrics(SM_CXSCREEN);    //水平

//         cyClient=GetSystemMetrics(SM_CYSCREEN);    //垂直

//         StringCchPrintf(szBuffer, 100, L"screen : %d * %d px", cxClient, cyClient);

//         //在屏幕中心写字

//         GetClientRect(hwnd, &rect);

//         DrawText(hdc, szBuffer, -1, &rect, DT_CENTER | DT_SINGLELINE | DT_VCENTER);

        EndPaint(hwnd, &ps);

        break;

    case WM_VSCROLL:

        hdc = GetDC(hwnd);

        GetClientRect(hwnd, &rect);

        if (LOWORD(wParam) == SB_LINEUP)

        {

            iVscrollPos -= ;

        }

        else if (LOWORD(wParam) == SB_LINEDOWN)

        {

            iVscrollPos += ;

        }

        else if (LOWORD(wParam) == SB_PAGEUP)

        {

            iVscrollPos -= cyClient / cyChar;

        }

        else if (LOWORD(wParam) == SB_PAGEDOWN)

        {

            iVscrollPos += cyClient / cyChar;

        }

        else if (LOWORD(wParam) == SB_THUMBTRACK)

        {

            DrawText(hdc, L"Slider.....", -, &rect, DT_RIGHT | DT_VCENTER);

        }

        else if (LOWORD(wParam) == SB_THUMBPOSITION)

        {

            iVscrollPos = HIWORD(wParam);

        }

        ReleaseDC(hwnd, hdc);

        iVscrollPos = max(, min(iVscrollPos, NUMLINES));

        if (iVscrollPos != GetScrollPos(hwnd, SB_VERT))

         {

            InvalidateRect(hwnd, NULL, TRUE);

            SetScrollPos(hwnd, SB_VERT, iVscrollPos, TRUE);

        }

        break;

    case WM_DESTROY:

        PostQuitMessage();

        break;

    case WM_QUIT:

        break;

    default:

        return DefWindowProc(hwnd, message, wParam, lParam);

    }

    return ;

}

巴特西

学习windows编程 day2 之滚动条使用

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