用Qt 怎么通过数组来画实时波形图

Posted 2023-03-09

参考技术A MoveTo,LineTo是画直线 Arc ArcTo是画弧线，你可以去查查函数用法，下面是画波形图的代码，有点复杂，看不太明白的话还是上网查MoveTo,LineTo的例子

#include <windows.h>

#include <math.h>

#define NUM 1000
#define TWOPI (2 * 3.14159)
LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;

int WINAPI WinMain ( HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR szCmdLine, int iCmdShow)

static TCHAR szAppName[] = TEXT ("SineWave") ;
HWND hwnd ;
MSG msg ;
WNDCLASS wndclass ;

wndclass.style = CS_HREDRAW | CS_VREDRAW ;
wndclass.lpfnWndProc= WndProc ;
wndclass.cbClsExtra = 0 ;
wndclass.cbWndExtra = 0 ;
wndclass.hInstance = hInstance ;
wndclass.hIcon = LoadIcon (NULL, IDI_APPLICATION) ;
wndclass.hCursor = LoadCursor (NULL, IDC_ARROW) ;
wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;
wndclass.lpszMenuName = NULL ;
wndclass.lpszClassName = szAppName ;

if (!RegisterClass (&wndclass))

MessageBox ( NULL, TEXT ("Program requires Windows NT!"),
szAppName, MB_ICONERROR) ;
return 0 ;


hwnd = CreateWindow ( szAppName, TEXT ("Sine Wave Using Polyline"),
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, CW_USEDEFAULT,
CW_USEDEFAULT, CW_USEDEFAULT,
NULL, NULL, hInstance, NULL) ;
ShowWindow (hwnd, iCmdShow) ;
UpdateWindow (hwnd) ;

while (GetMessage (&msg, NULL, 0, 0))

TranslateMessage (&msg) ;
DispatchMessage (&msg) ;

return msg.wParam ;


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

static int cxClient, cyClient ;
HDC hdc ;
int i ;
PAINTSTRUCT ps ;
POINT apt [NUM] ;

switch (message)

case WM_SIZE:
cxClient = LOWORD (lParam) ;
cyClient = HIWORD (lParam) ;
return 0 ;

case WM_PAINT:
hdc = BeginPaint (hwnd, &ps) ;

MoveToEx (hdc, 0, cyClient / 2, NULL) ;
LineTo (hdc, cxClient, cyClient / 2) ;

for (i = 0 ; i < NUM ; i++)

apt[i].x = i * cxClient / NUM ;
apt[i].y = (int) (cyClient / 2 * (1 - sin (TWOPI * i / NUM))) ;


Polyline (hdc, apt, NUM) ;
return 0 ;

case WM_DESTROY:
PostQuitMessage (0) ;
return 0 ;

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