为啥会一直刷新WM_PAINT函数？求解啊
本帖最后由 漠水 于 2015-1-9 09:22 编辑自制一个输出函数，调用后为啥会一直刷新#include<windows.h>
#include "strsafe.h"
LRESULT CALLBACK WndProc(HWND,UINT,WPARAM,LPARAM);
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow)
{
static TCHAR szAppName[] = TEXT("my windows");
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(""),szAppName,MB_OK);
return 0;
}
hwnd = CreateWindow(szAppName,
TEXT("这才是正文"),
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;
}
int print(HWND hwnd ,int ch,TCHAR cha[])
{
HDC hdc;
int x,y;
TCHAR szBuffer; //字符数组
size_t TT; //字符数组长度
TEXTMETRIC tm; // 字符的尺寸 TEXTMETRIC 结构记录当前设备环境中有关字体的各种信息
hdc = GetDC(hwnd);
GetTextMetrics(hdc,&tm);
x = tm.tmAveCharWidth; //字符的尺寸宽度
y = tm.tmHeight +tm.tmExternalLeading; //字符的尺寸高度+字符的尺寸上下间距
StringCchPrintf(szBuffer,128,cha); //
StringCchLength(szBuffer,128,&TT); //
TextOut(hdc,0,ch*y,szBuffer,TT);
ReleaseDC(hwnd,hdc); //
ch = ch + 1;
return ch;
}
LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
int ch = 0;
TCHAR szBuffer = TEXT("HELLO WORLD");
switch(message)
{
case WM_PAINT:
//s print(HWND hwnd ,s ch,TCHAR cha[])
ch = print(hwnd,ch,szBuffer);
ch = print(hwnd,ch,szBuffer);
return 0;
case WM_DESTROY:
PostQuitMessage(0);
return 0;
}
return DefWindowProc(hwnd,message,wParam,lParam);
}
http://baike.baidu.com/link?url=DMiXg_-CIhKpcW3y74wwJIqHtdSZ4t2-ZAud-7zxXdw0cXegeuV6ceBIolp5NwhyDZEAP5omCLuN4ZHPU4xieq 向往青莲 发表于 2015-1-8 10:48
http://baike.baidu.com/link?url=DMiXg_-CIhKpcW3y74wwJIqHtdSZ4t2-ZAud-7zxXdw0cXegeuV6ceBIolp5NwhyDZEA ...
原来是因为WM_PAINT函数必须以hdc = BeginPaint(hwnd,&ps);这语句作为开始
以EndPaint(hwnd,&ps);作为结束
不能用GetDC(hwnd)和Release(hwnd,hdc)作为开始和结束啊 我来看看{:1_1:} 围观学习 {:7_147:}
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