C++ 使用API C CFile CStdioFile读写文件

// FileOperationDlg.cpp: 实现文件
//

#include "pch.h"
#include "framework.h"
#include "FileOperation.h"
#include "FileOperationDlg.h"
#include "afxdialogex.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#endif


// 用于应用程序“关于”菜单项的 CAboutDlg 对话框

class CAboutDlg : public CDialogEx
{
public:
	CAboutDlg();

// 对话框数据
#ifdef AFX_DESIGN_TIME
	enum { IDD = IDD_ABOUTBOX };
#endif

	protected:
	virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV 支持

// 实现
protected:
	DECLARE_MESSAGE_MAP()
};

CAboutDlg::CAboutDlg() : CDialogEx(IDD_ABOUTBOX)
{
}

void CAboutDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialogEx::DoDataExchange(pDX);
}

BEGIN_MESSAGE_MAP(CAboutDlg, CDialogEx)
END_MESSAGE_MAP()


// CFileOperationDlg 对话框



CFileOperationDlg::CFileOperationDlg(CWnd* pParent /*=nullptr*/)
	: CDialogEx(IDD_FILEOPERATION_DIALOG, pParent)
	, m_strTextData(_T(""))
{
	m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CFileOperationDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialogEx::DoDataExchange(pDX);
	DDX_Text(pDX, IDC_EDIT1, m_strTextData);
}

BEGIN_MESSAGE_MAP(CFileOperationDlg, CDialogEx)
	ON_WM_SYSCOMMAND()
	ON_WM_PAINT()
	ON_WM_QUERYDRAGICON()
	ON_BN_CLICKED(IDC_BTN_APIWRITE, &CFileOperationDlg::OnBnClickedBtnApiwrite)
	ON_BN_CLICKED(IDC_BTN_APIREAD, &CFileOperationDlg::OnBnClickedBtnApiread)
	ON_BN_CLICKED(IDC_BTN_CWRITE, &CFileOperationDlg::OnBnClickedBtnCwrite)
	ON_BN_CLICKED(IDC_BTN_CREAD, &CFileOperationDlg::OnBnClickedBtnCread)
	ON_BN_CLICKED(IDC_BTN_CFileWRITE, &CFileOperationDlg::OnBnClickedBtnCfilewrite)
	ON_BN_CLICKED(IDC_BTN_CFileREAD, &CFileOperationDlg::OnBnClickedBtnCfileread)
	ON_BN_CLICKED(IDC_BTN_CStdioFileWRITE, &CFileOperationDlg::OnBnClickedBtnCstdiofilewrite)
	ON_BN_CLICKED(IDC_BTN_CStdioFileREAD, &CFileOperationDlg::OnBnClickedBtnCstdiofileread)
END_MESSAGE_MAP()


// CFileOperationDlg 消息处理程序

BOOL CFileOperationDlg::OnInitDialog()
{
	CDialogEx::OnInitDialog();

	// 将“关于...”菜单项添加到系统菜单中。

	// IDM_ABOUTBOX 必须在系统命令范围内。
	ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX);
	ASSERT(IDM_ABOUTBOX < 0xF000);

	CMenu* pSysMenu = GetSystemMenu(FALSE);
	if (pSysMenu != nullptr)
	{
		BOOL bNameValid;
		CString strAboutMenu;
		bNameValid = strAboutMenu.LoadString(IDS_ABOUTBOX);
		ASSERT(bNameValid);
		if (!strAboutMenu.IsEmpty())
		{
			pSysMenu->AppendMenu(MF_SEPARATOR);
			pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);
		}
	}

	// 设置此对话框的图标。  当应用程序主窗口不是对话框时，框架将自动
	//  执行此操作
	SetIcon(m_hIcon, TRUE);			// 设置大图标
	SetIcon(m_hIcon, FALSE);		// 设置小图标

	// TODO: 在此添加额外的初始化代码

	return TRUE;  // 除非将焦点设置到控件，否则返回 TRUE
}

void CFileOperationDlg::OnSysCommand(UINT nID, LPARAM lParam)
{
	if ((nID & 0xFFF0) == IDM_ABOUTBOX)
	{
		CAboutDlg dlgAbout;
		dlgAbout.DoModal();
	}
	else
	{
		CDialogEx::OnSysCommand(nID, lParam);
	}
}

// 如果向对话框添加最小化按钮，则需要下面的代码
//  来绘制该图标。  对于使用文档/视图模型的 MFC 应用程序，
//  这将由框架自动完成。

void CFileOperationDlg::OnPaint()
{
	if (IsIconic())
	{
		CPaintDC dc(this); // 用于绘制的设备上下文

		SendMessage(WM_ICONERASEBKGND, reinterpret_cast<WPARAM>(dc.GetSafeHdc()), 0);

		// 使图标在工作区矩形中居中
		int cxIcon = GetSystemMetrics(SM_CXICON);
		int cyIcon = GetSystemMetrics(SM_CYICON);
		CRect rect;
		GetClientRect(&rect);
		int x = (rect.Width() - cxIcon + 1) / 2;
		int y = (rect.Height() - cyIcon + 1) / 2;

		// 绘制图标
		dc.DrawIcon(x, y, m_hIcon);
	}
	else
	{
		CDialogEx::OnPaint();
	}
}

//当用户拖动最小化窗口时系统调用此函数取得光标
//显示。
HCURSOR CFileOperationDlg::OnQueryDragIcon()
{
	return static_cast<HCURSOR>(m_hIcon);
}



void CFileOperationDlg::OnBnClickedBtnApiwrite()
{
	// TODO: 在此添加控件通知处理程序代码
	UpdateData(TRUE);
	HANDLE hFile = ::CreateFile("test.txt", GENERIC_WRITE | GENERIC_READ, 0, NULL, CREATE_ALWAYS,
		FILE_ATTRIBUTE_NORMAL, NULL);
	if (hFile==NULL || hFile==INVALID_HANDLE_VALUE)
	{
		MessageBox(_T("打开文件失败"));
		return;
	}

	DWORD dwBytesWritten = 0;
	BOOL bRet = ::WriteFile(hFile, m_strTextData, m_strTextData.GetLength(), &dwBytesWritten, NULL);
	if (bRet==false || dwBytesWritten!=m_strTextData.GetLength())
	{
		MessageBox(_T("向文件写入数据失败"));
		return;
	}
	if (hFile!=NULL)
	{
		CloseHandle(hFile);
		hFile = NULL;
	}
}


void CFileOperationDlg::OnBnClickedBtnApiread()
{
	// TODO: 在此添加控件通知处理程序代码
	HANDLE hFile = ::CreateFile(_T("test.txt"), GENERIC_WRITE | GENERIC_READ, 0, NULL, OPEN_ALWAYS,
		FILE_ATTRIBUTE_NORMAL, NULL);
	if (hFile == NULL || hFile == INVALID_HANDLE_VALUE)
	{
		MessageBox(_T("打开文件失败"));
		return;
	}

	DWORD dwBytesRead = 0;
	char szbuf[1000];
	BOOL bRet = ::ReadFile(hFile, szbuf,sizeof(szbuf), &dwBytesRead, NULL);
	if (bRet == false )
	{
		MessageBox(_T("读取数据失败"));
		return;
	}
	szbuf[dwBytesRead] = 0;
	MessageBox(szbuf);
	if (hFile != NULL)
	{
		CloseHandle(hFile);
		hFile = NULL;
	}
}


void CFileOperationDlg::OnBnClickedBtnCwrite()
{
	// TODO: 在此添加控件通知处理程序代码
	UpdateData(TRUE);
	FILE* fp = fopen("test.txt", "w+");
	if (fp==NULL)
	{
		MessageBox("打开文件失败");
		return;
	}
	fwrite(m_strTextData, m_strTextData.GetLength(), 1, fp);
	fclose(fp);
}


void CFileOperationDlg::OnBnClickedBtnCread()
{
	// TODO: 在此添加控件通知处理程序代码

	FILE* fp = fopen("test.txt", "r");
	if (fp == NULL)
	{
		MessageBox("打开文件失败");
		return;
	}
	char szbuf[1000];
	size_t nBytesRead = 0;
	nBytesRead = fread(szbuf, 1, sizeof(szbuf), fp);
	szbuf[nBytesRead] = 0;
	MessageBox(szbuf);
	fclose(fp);
}


void CFileOperationDlg::OnBnClickedBtnCfilewrite()
{
	// TODO: 在此添加控件通知处理程序代码
	UpdateData(true);
	CFile file("test.txt", CFile::modeCreate | CFile::modeReadWrite);
	file.Write(m_strTextData, m_strTextData.GetLength());
	file.Close();
}


void CFileOperationDlg::OnBnClickedBtnCfileread()
{
	// TODO: 在此添加控件通知处理程序代码
	CFile file("test.txt", CFile::modeRead);
	char szbuf[1000];
	UINT nBytesRead = 0;
	nBytesRead = file.Read(szbuf, sizeof(szbuf));
	szbuf[nBytesRead] = 0;
	MessageBox(szbuf);
	file.Close();
}


void CFileOperationDlg::OnBnClickedBtnCstdiofilewrite()
{
	// TODO: 在此添加控件通知处理程序代码
	UpdateData(true);
	CStdioFile file("test.txt", CFile::modeCreate | CFile::modeReadWrite);
	file.WriteString(m_strTextData);
	file.Close();
}


void CFileOperationDlg::OnBnClickedBtnCstdiofileread()
{
	// TODO: 在此添加控件通知处理程序代码
	CStdioFile file("test.txt", CFile::modeRead);
	CString strbuf;
	if (!file.ReadString(strbuf))
	{
		MessageBox("读取文件失败");
		return;
	}
	MessageBox(strbuf);
	file.Close();
}