SetBkMode与SetBkColor的区别(代码搞定一切！！)

#include<windows.h>

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

int WINAPI WinMain(HINSTANCE hInstance,

HINSTANCE hPrevInstance,

PSTR szCmdLine,

int iCmdShow){

static TCHAR szAppName[]= TEXT("MyPen");

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(GRAY_BRUSH);

wndclass.lpszMenuName =NULL;

wndclass.lpszClassName = szAppName;

if(!RegisterClass(&wndclass)){

MessageBox(NULL, TEXT("Register failure..."),

szAppName, MB_ICONERROR);

return 0;

}

hwnd = CreateWindow(szAppName,

szAppName,

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)){

DispatchMessage(&msg);

TranslateMessage(&msg);

}

return msg.wParam;

}

LRESULT CALLBACK WndProc(HWND hwnd,

UINT message,

WPARAM wParam,

LPARAM lParam){

static int cxClient, cyClient, i;

HDC hdc;

PAINTSTRUCT ps;

HPEN hPen;

LOGPEN logPen;

switch(message){

case WM_SIZE:

cxClient = LOWORD(lParam);

cyClient = HIWORD(lParam);

i = 0;

return 0;

case WM_PAINT:

hdc = BeginPaint(hwnd,&ps);

SetBkColor(hdc, RGB(0, 255, 255));

// 注释运行和不注释它运行

// SetBkMode(hdc, TRANSPARENT); //若为OPAQUE标志则与上面一样

switch(i){

case 0:

hPen = CreatePen(PS_SOLID, 2, RGB(10, 10, 10));

break;

case 1:

hPen = CreatePen(PS_DASH, 1, RGB(20, 20, 20));

break;

case 2:

hPen = CreatePen(PS_DOT, 1, RGB(255, 30, 30));

break;

case 3:

hPen = CreatePen(PS_DASHDOT, 1, RGB(40, 40, 40));

break;

case 4:

hPen = CreatePen(PS_DASHDOTDOT, 1, RGB(50, 50, 50));

break;

case 5:

logPen.lopnStyle = PS_SOLID;

logPen.lopnColor = RGB(0, 60, 60);

/*

* 此处是非常有意思的，下面有说明

*/

logPen.lopnWidth.x = 5;

hPen = CreatePenIndirect(&logPen);

break;

default:

hPen =(HPEN) GetStockObject(BLACK_PEN);

break;

}

SelectObject(hdc, hPen);

MoveToEx(hdc, 0,(i + 1)* cyClient / 10,NULL);

LineTo(hdc, cxClient,(i + 1)* cyClient / 10);

TextOut(hdc, i* cxClient / 7, 4 * cyClient / 5,"windows", lstrlen("windows"));

if(i++<= 5)

InvalidateRect(hwnd,NULL,FALSE);

EndPaint(hwnd, &ps);

// 删除GDI对象， 释放内存！！

DeleteObject(hPen);

return 0;

case WM_DESTROY:

PostQuitMessage(0);

return 0;

}

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

}