几个常见Win32 API函数

1.获取客户区矩形区域

RECT cliRect;
GetClientRect(hWnd, &cliRect);

2.获取窗口上下文句柄

HDC hdc = GetDC(hWnd);
//....
ReleaseDC(hWnd, hdc);

3.LPWSTR   与 char * 互转

int32_t WToChar(LPWSTR szWstr, char szCstr[], const int32_t chrLen)
{
    int iLength = WideCharToMultiByte(CP_ACP, , szWstr, -, NULL, , NULL, NULL);
    return WideCharToMultiByte(CP_ACP, , szWstr, -, szCstr, iLength, NULL, NULL);
}

int32_t CharToW(const char* szCstr, WCHAR szWstr[], const int32_t wstrLen)
{
    int iLength = MultiByteToWideChar(CP_ACP, MB_PRECOMPOSED, szCstr, -, NULL, );
    return MultiByteToWideChar(CP_ACP, MB_PRECOMPOSED, szCstr, -, szWstr, iLength);
}

4.获取带颜色的画刷

COLORREF colorObs = 0x9D9D9D;
HBRUSH hbObs = CreateSolidBrush(colorObs);

//....

DeleteObject(hbObs);

5.绘制矩形

Rectangle(hdc ,left,top,right,bottom);

6.填充矩形

FillRect(hdc, &rect, hbObs);

7.刷新整个窗口

InvalidateRect(hWnd, NULL, TRUE);

8.设置窗口标题

SetWindowText(hWnd, szText);

9.打开文件对话框

bool OpenFileDialog(HWND hWnd, char szFileName[MAX_PATH])
{
    WCHAR szFile[MAX_PATH] = {  };
    OPENFILENAME ofn = { OPENFILENAME_SIZE_VERSION_400 };
    ofn.hwndOwner = hWnd;
    // 过滤器,以\0相隔: 显示名称\0过滤器\0显示名称\0过滤器\0\0
    ofn.lpstrFilter = TEXT("txt(*.txt)\0*.txt\0All Files(*.*)\0*.*\0\0");
    ofn.lpstrFile = szFile;
    ofn.nMaxFile = sizeof(szFile);
    ofn.lpstrTitle = TEXT("选择文件");
    ofn.Flags = OFN_EXPLORER | OFN_FILEMUSTEXIST | OFN_PATHMUSTEXIST;
    TCHAR szCurDir[MAX_PATH];
    GetCurrentDirectory(sizeof(szCurDir), szCurDir);
    ofn.lpstrInitialDir = szCurDir;//设置对话框显示的初始目录
    BOOL bOk = GetOpenFileName(&ofn);
    if (!bOk)
    {
        return false;
    }
    //MessageBox(NULL, ofn.lpstrFile, TEXT("Tips_Yes"), MB_OK);
    memset(szFileName, , sizeof(szFileName));
    WToChar(ofn.lpstrFile, szFileName, sizeof(szFileName));
    return true;
}

10.保存文件对话框

bool SaveFileDialog(HWND hWnd, char szFileName[MAX_PATH])
{
    WCHAR szFile[MAX_PATH] = {  };
    OPENFILENAME ofn = { OPENFILENAME_SIZE_VERSION_400 };
    ofn.hwndOwner = hWnd;
    // 过滤器,以\0相隔: 显示名称\0过滤器\0显示名称\0过滤器\0\0
    ofn.lpstrFilter = TEXT("txt(*.txt)\0*.txt\0All Files(*.*)\0*.*\0\0");
    ofn.lpstrFile = szFile;
    ofn.nMaxFile = sizeof(szFile);
    ofn.lpstrTitle = TEXT("选择文件");
    ofn.Flags = OFN_OVERWRITEPROMPT;        // 覆盖提示
    TCHAR szCurDir[MAX_PATH];
    GetCurrentDirectory(sizeof(szCurDir), szCurDir);
    ofn.lpstrInitialDir = szCurDir;//设置对话框显示的初始目录
    BOOL bOk = GetSaveFileName(&ofn);
    if (!bOk)
    {
        return false;
    }
    //MessageBox(NULL, ofn.lpstrFile, TEXT("Tips_Yes"), MB_OK);
    memset(szFileName, , sizeof(szFileName));
    WToChar(ofn.lpstrFile, szFileName, sizeof(szFileName));
    return true;
}

11.获取或设置控件文字

GetDlgItemText(hDlg, IDC_EDIT_ROW, szTRow, );
SetDlgItemText(hDlg, IDC_EDIT_COL, szTCol);

12.获取光标位置

POINT pt;
GetCursorPos(&pt);

13.屏幕坐标与窗口坐标之间的转化

ScreenToClient(hWnd, &pt);
ClientToScreen(hWnd, &pt);

14.设置窗口位置和大小

SetWindowPos(hWnd, NULL, nX, nY, nWidth, nHeight, false);

15. 打开右键菜单

void UIManager::OnContextMenu(const HWND &hWnd, const RECT &cliRect, const POINT &clickPt)
{
    POINT tmpt = clickPt;
    ScreenToClient(hWnd, &tmpt);
    if (PtInRect(&cliRect, tmpt) == FALSE){ return; }
    HMENU hroot = LoadMenu((HINSTANCE)GetWindowLongPtr(hWnd, GWLP_HINSTANCE), MAKEINTRESOURCE(IDR_CONTEXT));
    if (!hroot){ return; }
    HMENU hpop = GetSubMenu(hroot, 0);
    if (!hpop){ return; }
    ClientToScreen(hWnd, &tmpt);
    //显示快捷菜单
    TrackPopupMenu(hpop,
        TPM_LEFTALIGN | TPM_TOPALIGN | TPM_RIGHTBUTTON,
        tmpt.x,
        tmpt.y,
        ,
        hWnd,
        NULL);
    // 用完后要销毁菜单资源
    DestroyMenu(hroot);
}