（1）、UTF16LE
把CString中的内容写到UTF16LE中去，可以使用WriteString或者Write。
WriteString函数会把UNICODE字符串以UTF16LE编码格式写入，遇到空字符会提前结束
Write函数则不受空字符的影响，不会提前结束。
使用WriteString向UTF16LE中写入CString类型的文本。
cpp
CStdioFileCodePage file1;
if (!file1.OpenWithoutType(CppFile, CFile::modeRead))
{
file1.Close();
return false;
}
CStdioFile tempFile;
CString tempFileName = CppFile + L".tmp";
if (!tempFile.Open(tempFileName, CFile::modeCreate | CFile::modeWrite | CFile::typeUnicode))
{
tempFile.Close();
return false;
}
CString line;
while (file1.ReadStringWithOutType(line))
{
if (line.Compare(msg3) != 0)
{
tempFile.WriteString(line + L"\n");
}
else
{
break;
}
}
tempFile.Close();
file1.Close();
CFile::Remove(CppFile);
CFile::Rename(tempFileName, CppFile);
CStdioFile file;
if (!file.Open(CppFile, CFile::modeWrite | CFile::typeUnicode))
{
file.Close();
return false;
}
file.SeekToEnd();
file.WriteString(finamsg);
file.Close();
return true;WriteString在写入文本内容后可以指针定位在文件末尾追加
Write再写入后如果没有包含CFile::modeNoTruncate模式则会选择覆盖原本内容
使用Write函数向UTF16LE中写入CString内容。
cpp
file.Write(finamsg, finamsg.GetLength() * sizeof(wchar_t));内容如果写的不完全注意：UTF16是一个字符由俩个字节表示，所以在第二个参数*2.
（2）、UTF16BE
UTF16BE和UTF16LE的区别
1）、UTF16BE是大端序存储，也就是开头有大端BOM，UTF16LE是小端序存储，也就是开头有小端BOM。
2）、由于MFC中默认不支持自动添加大端序BOM所以在创建UTF16BE的时候要使用CFile::typeBinary模式来手动处理字节顺序，确保文件以大端字节顺序存储Unicode字符.而创建小端序可以直接使用UNICODE默认的方式创建。
把CString中的文本写入到UTF16BE中
cpp
CStdioFileCodePage file1;
if (!file1.OpenWithoutType(CppFile, CFile::modeRead))
{
file1.Close();
return false;
}
CStdioFile tempFile;
CString tempFileName = CppFile + L".tmp";
if (!tempFile.Open(tempFileName, CFile::modeCreate | CFile::modeWrite | CFile::typeBinary))
{
tempFile.Close();
return false;
}
CString line;
//写入UTF - 16BE的BOM
unsigned char bom[2] = { 0xFE, 0xFF };
tempFile.Write(bom, 2);
while (file1.ReadStringWithOutType(line))
{
if (line.Compare(msg3) != 0)
{
/* tempFile.WriteString(line + L"\n");*/
// 将CString对象转换为宽字符格式，并按照大端序写入文件
CStringW wideStr = CStringW(line + L"\n"); // 将CString换为宽字符格式
int len = wideStr.GetLength();
for (int i = 0; i < len; i++)
{
unsigned short ch = _byteswap_ushort(wideStr[i]); // 将字节序颠倒
tempFile.Write(&ch, sizeof(unsigned short)); // 按照大端序写入文件
}
}
else
{
break;
}
}
tempFile.Close();
file1.Close();
CFile::Remove(CppFile);
CFile::Rename(tempFileName, CppFile);
CStdioFile file;
if (!file.Open(CppFile, CFile::modeWrite | CFile::typeBinary))
{
file.Close();
return false;
}
file.SeekToEnd();
CStringW wideStr = CStringW(msg); // 将CString换为宽字符格式
int len = wideStr.GetLength();
for (int i = 0; i < len; i++)
{
unsigned short ch = _byteswap_ushort(wideStr[i]); // 将字节序颠倒
file.Write(&ch, sizeof(unsigned short)); // 按照大端序写入文件
}
file.Close();
return true;注意：写入大端序中的字符顺序需要颠倒
（3）、ANSI
ANSI本地默认编码格式，创建的时候使用CFile::typeText默认选择ANSI编码格式
写入ANSI中需要写入CStringA类型（char *msg也可以）
cpp
CStdioFileCodePage file1;
if (!file1.OpenWithoutType(CppFile, CFile::modeRead))
{
file1.Close();
return false;
}
CStdioFile tempFile;
CString tempFileName = CppFile + L".tmp";
if (!tempFile.Open(tempFileName, CFile::modeCreate | CFile::modeWrite | CFile::typeText))
{
tempFile.Close();
return false;
}
CString line;
while (file1.ReadStringWithOutType(line))
{
if (line.Compare(msg3) != 0)
{
tempFile.WriteString(line + L"\n");
}
else
{
break;
}
}
tempFile.Close();
file1.Close();
CFile::Remove(CppFile);
CFile::Rename(tempFileName, CppFile);
CStdioFile file;
if (!file.Open(CppFile, CFile::modeWrite | CFile::typeText| CFile::modeNoTruncate))
{
file.Close();
return false;
}
file.SeekToEnd();
file.Write(msg, strlen(msg));
file.Close();
return true;注意：写入如果发现原先的内容被覆盖说明打开的方式不正确 CFile::modeNoTruncate
（4）、UTF8
与ANSI创建打开文件方法相同，但是区别在于系统默认当前是ANSI，我们需要把CString变量转换成UTF8类型的CStringA变量再写入
cpp
CStdioFileCodePage file1;
if (!file1.OpenWithoutType(CppFile, CFile::modeRead | CFile::typeText))
{
file1.Close();
return false;
}
file1.JumpBOM();
CStdioFile tempFile;
CString tempFileName = CppFile + L".tmp";
if (!tempFile.Open(tempFileName, CFile::modeCreate | CFile::modeWrite | CFile::typeText))
{
tempFile.Close();
return false;
}
// 设置文件流的locale为UTF-8编码
//tempFile.WriteString(L"\xEF\xBB\xBF"); // 写入UTF-8的BOM
CString line;
while (file1.ReadStringWithOutType(line))
{
if (line.Compare(msg3) != 0)
{
CStringA lineUTF8 = CW2A(line, CP_UTF8);
lineUTF8 += L"\n";
tempFile.Write(lineUTF8,strlen(lineUTF8));
}
else
{
break;
}
}
// 刷新文件流
tempFile.Flush();
tempFile.Close();
file1.Close();
CFile::Remove(CppFile);
CFile::Rename(tempFileName, CppFile);
// 打开文件以UTF-8编码形式写入文本数据
CStdioFile file;
if (!file.Open(CppFile, CFile::modeWrite | CFile::modeNoTruncate | CFile::typeText))
{
file.Close();
return false;
}
file.SeekToEnd();
// 将msg转换为UTF-8编码的CStringA
CStringA msgUTF8 = CW2A(msg, CP_UTF8);
// 使用CStringA来写入UTF-8编码的内容
file.Write(msgUTF8,strlen(msgUTF8));
file.Close();
return true;（5）、UTF8BOM
相对于UTF8前面有BOM。
cpp
CStdioFileCodePage file1;
if (!file1.OpenWithoutType(CppFile, CFile::modeRead | CFile::typeText))
{
file1.Close();
return false;
}
file1.JumpBOM();
CStdioFile tempFile;
CString tempFileName = CppFile + L".tmp";
if (!tempFile.Open(tempFileName, CFile::modeCreate | CFile::modeWrite | CFile::typeText))
{
tempFile.Close();
return false;
}
tempFile.WriteString(L"\xEF\xBB\xBF"); // 写入UTF-8的BOM
CString line;
while (file1.ReadStringWithOutType(line))
{
if (line.Compare(msg3) != 0)
{
CStringA lineUTF8 = CW2A(line, CP_UTF8);
lineUTF8 += L"\n";
tempFile.Write(lineUTF8, strlen(lineUTF8));
}
else
{
break;
}
}
// 刷新文件流
tempFile.Flush();
tempFile.Close();
file1.Close();
CFile::Remove(CppFile);
CFile::Rename(tempFileName, CppFile);
// 打开文件以UTF-8编码形式写入文本数据
CStdioFile file;
if (!file.Open(CppFile, CFile::modeWrite | CFile::modeNoTruncate | CFile::typeText))
{
file.Close();
return false;
}
file.SeekToEnd();
// 将msg转换为UTF-8编码的CStringA
CStringA msgUTF8 = CW2A(msg, CP_UTF8);
// 使用CStringA来写入UTF-8编码的内容
file.Write(msgUTF8, strlen(msgUTF8));
file.Close();
return true;