Windows API 中的自定义控件
在这里,我们将演示如何创建自己的自定义控件。 Windows API 具有各种预先构建的控件的集合。 必须手动创建更多特定的控件。 我们使用 GDI 创建自定义控件。
刻录控件
可以在各种媒体刻录应用中找到此控件,例如 Nero 刻录 ROM。
#include <windows.h>
#include <commctrl.h>
#include <wchar.h>
LRESULT CALLBACK PanelProc(HWND, UINT, WPARAM, LPARAM);
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
HINSTANCE g_hinst;
LRESULT g_pos = 150;
int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
PWSTR lpCmdLine, int nCmdShow)
{
HWND hwnd;
MSG msg;
WNDCLASSW wc = {0};
wc.lpszClassName = L"Application";
wc.hInstance = hInstance;
wc.hbrBackground = GetSysColorBrush(COLOR_3DFACE);
wc.lpfnWndProc = WndProc;
wc.hCursor = LoadCursor(0, IDC_ARROW);
g_hinst = hInstance;
RegisterClassW(&wc);
hwnd = CreateWindowW(wc.lpszClassName, L"Burning control",
WS_OVERLAPPEDWINDOW | WS_VISIBLE | WS_CLIPCHILDREN,
100, 100, 400, 250, 0, 0, hInstance, 0);
while( GetMessage(&msg, NULL, 0, 0)) {
DispatchMessage(&msg);
}
return (int) msg.wParam;
}
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg,
WPARAM wParam, LPARAM lParam)
{
static HWND hwndTrack, hwndBurn;
WNDCLASSW rwc = {0};
INITCOMMONCONTROLSEX InitCtrlEx;
InitCtrlEx.dwSize = sizeof(INITCOMMONCONTROLSEX);
InitCtrlEx.dwICC = ICC_BAR_CLASSES;
InitCommonControlsEx(&InitCtrlEx);
switch(msg)
{
case WM_CREATE:
rwc.lpszClassName = L"BurningControl";
rwc.hbrBackground = GetSysColorBrush(COLOR_BTNFACE);
rwc.style = CS_HREDRAW;
rwc.lpfnWndProc = PanelProc;
rwc.hCursor = LoadCursor(0, IDC_ARROW);
RegisterClassW(&rwc);
hwndBurn = CreateWindowExW(WS_EX_STATICEDGE , L"BurningControl", NULL,
WS_CHILD | WS_VISIBLE, 0, 330, 490, 30, hwnd, (HMENU)1, NULL, NULL);
hwndTrack = CreateWindowExW(0, TRACKBAR_CLASSW, NULL,
WS_CHILD | WS_VISIBLE | TBS_FIXEDLENGTH | TBS_NOTICKS,
40, 25, 150, 25, hwnd, (HMENU) 2, g_hinst, NULL);
SendMessage(hwndTrack, TBM_SETRANGE, TRUE, MAKELONG(0, 750));
SendMessage(hwndTrack, TBM_SETPAGESIZE, 0, 20);
SendMessage(hwndTrack, TBM_SETTICFREQ, 20, 0);
SendMessage(hwndTrack, TBM_SETPOS, TRUE, 150);
break;
case WM_SIZE:
SetWindowPos(hwndBurn, NULL, 0, HIWORD(lParam)-30,
LOWORD(lParam), 30, SWP_NOZORDER);
break;
case WM_HSCROLL:
g_pos = SendMessage(hwndTrack, TBM_GETPOS, 0, 0);
InvalidateRect(hwndBurn, NULL, TRUE);
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
}
return DefWindowProcW(hwnd, msg, wParam, lParam);
}
LRESULT CALLBACK PanelProc(HWND hwnd, UINT msg,
WPARAM wParam, LPARAM lParam)
{
HBRUSH hBrushYellow, hBrushRed, holdBrush;
HPEN hPen, holdPen;
HFONT hFont, holdFont;
PAINTSTRUCT ps;
RECT rect, rect2;
wchar_t *cap[] = { L"75", L"150", L"225", L"300", L"375", L"450",
L"525", L"600", L"675"};
HDC hdc;
int till;
int step, full;
int i;
switch(msg)
{
case WM_PAINT:
hdc = BeginPaint(hwnd, &ps);
GetClientRect(hwnd, &rect);
till = (rect.right / 750.0) * g_pos;
step = rect.right / 10.0;
full = (rect.right / 750.0) * 700;
hBrushYellow = CreateSolidBrush(RGB(255, 255, 184));
hBrushRed = CreateSolidBrush(RGB(255, 110, 110));
hPen = CreatePen(PS_NULL, 1, RGB(0, 0, 0));
holdPen = SelectObject(hdc, hPen);
hFont = CreateFontW(13, 0, 0, 0, FW_MEDIUM, 0, 0, 0, 0,
0, 0, 0, 0, L"Tahoma");
holdFont = SelectObject(hdc, hFont);
if(till > full) {
SelectObject(hdc, hBrushYellow);
Rectangle(hdc, 0, 0, full, 30);
holdBrush = SelectObject(hdc, hBrushRed);
Rectangle(hdc, full, 0, till, 30);
} else {
holdBrush = SelectObject(hdc, hBrushYellow);
Rectangle(hdc, 0, 0, till, 30);
}
SelectObject(hdc, holdPen);
for ( i = 1; i < 10; i++) {
MoveToEx(hdc, i*step, 0, NULL);
LineTo(hdc, i*step, 7);
rect2.bottom = 28;
rect2.top = 8;
rect2.left = i*step-10;
rect2.right = i*step+10;
SetBkMode(hdc, TRANSPARENT) ;
DrawTextW(hdc, cap[i-1], wcslen(cap[i-1]), &rect2, DT_CENTER);
}
SelectObject(hdc, holdBrush);
DeleteObject(hBrushYellow);
DeleteObject(hBrushRed);
DeleteObject(hPen);
SelectObject(hdc, holdFont);
DeleteObject(hFont);
EndPaint(hwnd, &ps);
break;
}
return DefWindowProcW(hwnd, msg, wParam, lParam);
}
在我们的示例中,我们显示一个轨迹栏控件和我们的自定义刻录控件。 跟踪栏控件用于控制刻录控件的状态。
刻录控件是一个简单的窗口。 它放置在父窗口的底部。 它在WM_PAINT
消息期间被完全绘制。 使用 GDI 函数调用绘制线条,文本和背景。
图:刻录控件
在 Windows API 教程的这一部分中,我们创建了刻录自定义控件。