更新时间:2016-02-16 16:02:55浏览次数:1+次
我们首先来看看我们要实现的效果,如下图所示:
typedef struct tagDRAWITEMSTRUCT {
UINT CtlType; //控件类型
UINT CtlID; //控件ID
UINT itemID; //列表框的项的索引值或者组合框
UINT itemAction;//绘制动作标志
UINT itemState; //项的状态
HWND hwndItem; //控件的句柄
HDC hDC; //控件传递过来绘图的DC句柄
RECT rcItem; //控件的矩形大小
ULONG_PTR itemData; //菜单相关,这里不讨论
} DRAWITEMSTRUCT;
从DRAWITEMSTRUCT结构体的声明中我们可以看到我们需要的参数都在结构体里了。在WM_DRAWITEM消息的WPARAM参数中,携带了控件的ID,和结构体里的控件ID是一样的。LPARAM参数中携带了指向DRAWITEMSTRUCT结构体变量的地址。UINT iCtlID = wParam;//如果此消息是菜单发送的,此值就是0,否则就是发送此消息的控件ID
LPDRAWITEMSTRUCT lpDrawItemStruct = (LPDRAWITEMSTRUCT)lParam;
HDC hdc = lpDrawItemStruct->hDC;
提取了这些参数,我们后面写代码就方便了。我们这里就单独对按钮控件进行重绘,所以可以不用判断控件的类型。不过我们还是要用到控件的ID来判断一下。如果不是我们指定的ID的控件发过来的自绘消息,我们不予处理。#include "windows.h"
#include <tchar.h>
TCHAR tip[]=_T("C++技术网http://www.cjjjs.com");
LRESULT CALLBACK WinProc(HWND hwnd,UINT message,WPARAM wParam,LPARAM lParam)
{
switch (message)
{
case WM_CREATE:
{
CreateWindow(_T("button"),_T("C++技术网\r\nhttp://www.cjjjs.com"),WS_CHILD|WS_VISIBLE|BS_OWNERDRAW,0,0,130,50,hwnd,(HMENU)1,(HINSTANCE)GetWindowLong(hwnd,GWL_HINSTANCE),0);
return 0;
}
case WM_DRAWITEM:
{
UINT iCtlID = wParam;//如果此消息是菜单发送的,此值就是0,否则就是发送此消息的控件ID
LPDRAWITEMSTRUCT lpDrawItemStruct = (LPDRAWITEMSTRUCT)lParam;
HDC hdc = lpDrawItemStruct->hDC;
if (iCtlID==1)
{
SetBkMode(hdc,TRANSPARENT);//设置文字背景模式为透明的
if (lpDrawItemStruct->itemState&ODS_SELECTED)//检测按钮是否是被单击按下时要求的重绘
{
//单击按钮时
FrameRect(hdc,&lpDrawItemStruct->rcItem,(HBRUSH)GetStockObject(WHITE_BRUSH));
FillRect(hdc,&lpDrawItemStruct->rcItem,(HBRUSH)GetStockObject(DKGRAY_BRUSH));
SetTextColor(hdc,RGB(255,255,0));
}
else
{
FrameRect(hdc,&lpDrawItemStruct->rcItem,(HBRUSH)GetStockObject(LTGRAY_BRUSH));
FillRect(hdc,&lpDrawItemStruct->rcItem,(HBRUSH)GetStockObject(LTGRAY_BRUSH));
SetTextColor(hdc,RGB(0,0,0));
}
DrawText(hdc,tip,-1,&lpDrawItemStruct->rcItem,DT_WORDBREAK|DT_CENTER|DT_VCENTER);
SetBkMode(hdc,OPAQUE);//恢复文字背景模式
SetTextColor(hdc,RGB(0,0,0));//恢复文字颜色
}
}
return FALSE;
case WM_DESTROY:
PostQuitMessage(0);
return 0;
default:
break;//跳出到默认处理
}
return DefWindowProc(hwnd, message, wParam, lParam);
}
int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrev,LPSTR lpCmd,int iShow)
{
TCHAR ClassName[] = _T("MyClass");
TCHAR title1[] = _T("C++技术网http://www.cjjjs.com");
WNDCLASS wndClass;
wndClass.cbClsExtra=0;
wndClass.cbWndExtra=0;
wndClass.hbrBackground= (HBRUSH)GetStockObject(WHITE_BRUSH);
wndClass.hCursor=LoadCursor(NULL,IDC_ARROW);
wndClass.hIcon=LoadIcon(NULL,IDI_APPLICATION);
wndClass.hInstance = hInstance;
wndClass.lpfnWndProc = WinProc;
wndClass.lpszClassName = ClassName;
wndClass.lpszMenuName=NULL;
wndClass.style=CS_HREDRAW|CS_VREDRAW|CS_DBLCLKS;
if(!RegisterClass(&wndClass))return 0;
HWND hwnd = CreateWindow(ClassName,title1,WS_OVERLAPPEDWINDOW,10,100,600,400,NULL,NULL,hInstance,NULL);
ShowWindow(hwnd,SW_SHOWNORMAL);
MSG msg;
while (GetMessage(&msg,NULL,0,0))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return msg.wParam;
}
相关资讯