diff --git a/core/Common/Image.cpp b/core/Common/Image.cpp
index 9f8c3b56..b7f33899 100644
--- a/core/Common/Image.cpp
+++ b/core/Common/Image.cpp
@@ -41,7 +41,7 @@ void e2d::Image::loadFrom(const String & strFilePath)
 		return;
 	}
 
-	m_pBitmap = s_mBitmapsFromFile.at(strFilePath.hash());
+	m_pBitmap = s_mBitmapsFromFile.at(strFilePath.getHash());
 	m_fSourceClipX = m_fSourceClipY = 0;
 	m_fSourceClipWidth = m_pBitmap->GetSize().width;
 	m_fSourceClipHeight = m_pBitmap->GetSize().height;
@@ -132,7 +132,7 @@ e2d::Point e2d::Image::getClipPos() const
 
 bool e2d::Image::preload(const String & fileName)
 {
-	if (s_mBitmapsFromFile.find(fileName.hash()) != s_mBitmapsFromFile.end())
+	if (s_mBitmapsFromFile.find(fileName.getHash()) != s_mBitmapsFromFile.end())
 	{
 		return true;
 	}
@@ -192,7 +192,7 @@ bool e2d::Image::preload(const String & fileName)
 		// 保存图片指针和图片的 Hash 名
 		s_mBitmapsFromFile.insert(
 			std::map<size_t, ID2D1Bitmap*>::value_type(
-				fileName.hash(),
+				fileName.getHash(),
 				pBitmap)
 		);
 	}
diff --git a/core/Common/String.cpp b/core/Common/String.cpp
index c872ff83..50c1aef4 100644
--- a/core/Common/String.cpp
+++ b/core/Common/String.cpp
@@ -1,148 +1,60 @@
 #include "..\ecommon.h"
 #include <iomanip>
-using namespace e2d;
 
 
-String::String()
+e2d::String::String()
+	: m_str(L"")
 {
-	_size = 0;
-	_string = new wchar_t[1];
-	_string[0] = 0;
 }
 
-e2d::String::String(const wchar_t ch)
+e2d::String::String(const wchar_t *str)
+	: m_str(str)
 {
-	_size = 1;
-	_string = new wchar_t[2];
-	_string[0] = ch;
-	_string[1] = 0;
 }
 
-String::String(const wchar_t *str)
+e2d::String::String(e2d::String && str)
 {
-	if (str)
-	{
-		_size = static_cast<int>(wcslen(str));
-		_string = new wchar_t[_size + 1];
-		wcscpy_s(_string, _size + 1, str);
-	}
-	else
-	{
-		_size = 0;
-		_string = new wchar_t[1];
-		_string[0] = 0;
-	}
+	m_str = std::move(str.m_str);
 }
 
-String::String(String && str)
+e2d::String::String(const e2d::String &str)
+	: m_str(str.m_str)
 {
-	_size = str._size;
-	_string = str._string;
-	str._string = nullptr;
-}
-
-String::String(const String &str)
-{
-	if (str._size)
-	{
-		_size = str._size;
-		_string = new wchar_t[_size + 1];
-		wcscpy_s(_string, _size + 1, str._string);
-	}
-	else
-	{
-		_size = 0;
-		_string = new wchar_t[1];
-		_string[0] = 0;
-	}
 }
 
 e2d::String::String(const std::wstring &str)
+	: m_str(str)
 {
-	if (!str.empty())
-	{
-		_size = static_cast<int>(str.length());
-		_string = new wchar_t[_size + 1];
-		wcscpy_s(_string, _size + 1, str.c_str());
-	}
-	else
-	{
-		_size = 0;
-		_string = new wchar_t[1];
-		_string[0] = 0;
-	}
 }
 
-String::~String()
+e2d::String::~String()
 {
-	delete[] _string;
+	m_str.clear();
 }
 
-String &String::operator=(const wchar_t *str)
+e2d::String &e2d::String::operator=(const wchar_t *str)
 {
-	if (_string == str)
-		return *this;
-
-	if (str)
-	{
-		delete[] _string;
-		_size = static_cast<int>(wcslen(str));
-		_string = new wchar_t[_size + 1];
-		wcscpy_s(_string, _size + 1, str);
-	}
-	else
-	{
-		_size = 0;
-		_string = new wchar_t[1];
-		_string[0] = 0;
-	}
+	m_str = str;
 	return *this;
 }
 
-String &String::operator=(const String &str)
+e2d::String & e2d::String::operator=(const String &str)
 {
-	if (_string == str._string)
-		return *this;
-
-	if (str._size)
-	{
-		delete[] _string;
-		_size = str._size;
-		_string = new wchar_t[_size + 1];
-		wcscpy_s(_string, _size + 1, str._string);
-	}
-	else
-	{
-		_size = 0;
-		_string = new wchar_t[1];
-		_string[0] = 0;
-	}
+	m_str = str.m_str;
 	return *this;
 }
 
-String & e2d::String::operator=(const std::wstring &str)
+e2d::String & e2d::String::operator=(const std::wstring &str)
 {
-	if (!str.empty())
-	{
-		delete[] _string;
-		_size = static_cast<int>(str.length());
-		_string = new wchar_t[_size + 1];
-		wcscpy_s(_string, _size + 1, str.c_str());
-	}
-	else
-	{
-		_size = 0;
-		_string = new wchar_t[1];
-		_string[0] = 0;
-	}
+	m_str = str;
 	return *this;
 }
 
-bool String::operator==(const wchar_t *str)
+bool e2d::String::operator==(const wchar_t *str)
 {
 	if (str)
 	{
-		return (wcscmp(str, _string) == 0);
+		return (m_str.compare(str) == 0);
 	}
 	else
 	{
@@ -150,248 +62,227 @@ bool String::operator==(const wchar_t *str)
 	}
 }
 
-bool String::operator ==(const String &str)
+bool e2d::String::operator ==(const e2d::String &str)
 {
-	return (wcscmp(str._string, _string) == 0);
+	return m_str == str.m_str;
 }
 
 bool e2d::String::operator==(const std::wstring &str)
 {
-	return (str.compare(_string) == 0);
+	return m_str == str;
 }
 
 bool e2d::String::operator!=(const wchar_t *str)
 {
-	return (wcscmp(str, _string) != 0);
+	if (str)
+	{
+		return (m_str.compare(str) != 0);
+	}
+	else
+	{
+		return true;
+	}
 }
 
-bool e2d::String::operator!=(const String &str)
+bool e2d::String::operator!=(const e2d::String &str)
 {
-	return (wcscmp(str._string, _string) != 0);
+	return m_str != str.m_str;
 }
 
 bool e2d::String::operator!=(const std::wstring &str)
 {
-	return (str.compare(_string) != 0);
+	return m_str != str;
 }
 
-wchar_t &String::operator[](int index)
+wchar_t &e2d::String::operator[](int index)
 {
-	ASSERT(index >= 0 && index < _size, "String subscript out of range");
-	return _string[index];
+	return m_str[static_cast<size_t>(index)];
 }
 
-String String::operator+(const wchar_t *str)
+e2d::String e2d::String::operator+(const wchar_t *str)
 {
-	String str_temp(*this);
-
-	str_temp += str;
-	return std::move(str_temp);
+	String temp;
+	temp.m_str = m_str + str;
+	return std::move(temp);
 }
 
-String String::operator+(const wchar_t x)
+e2d::String e2d::String::operator+(const wchar_t x)
 {
-	String str_temp(*this);
-
-	str_temp += x;
-	return std::move(str_temp);
+	String temp;
+	temp.m_str = m_str + x;
+	return std::move(temp);
 }
 
-String String::operator+(const String &str)
+e2d::String e2d::String::operator+(const e2d::String &str)
 {
-	String str_temp(*this);
-
-	str_temp += str;
-	return std::move(str_temp);
+	String temp;
+	temp.m_str = m_str + str.m_str;
+	return std::move(temp);
 }
 
-String e2d::String::operator+(const std::wstring &str)
+e2d::String e2d::String::operator+(const std::wstring &str)
 {
-	String str_temp(*this);
-
-	str_temp += str;
-	return std::move(str_temp);
+	String temp;
+	temp.m_str = m_str + str;
+	return std::move(temp);
 }
 
-String &String::operator+=(const wchar_t x)
+e2d::String e2d::operator+(const wchar_t ch, const e2d::String &str)
 {
-	wchar_t *str_temp = new wchar_t[_size + 2];
-	if (_string) wcscpy_s(str_temp, _size + 2, _string);
-	str_temp[_size] = x;
-	str_temp[_size + 1] = 0;
+	String temp;
+	temp.m_str = ch + str.m_str;
+	return std::move(temp);
+}
 
-	delete[] _string;
-	_string = str_temp;
-	_size++;
+e2d::String e2d::operator+(const wchar_t *str1, const e2d::String &str2)
+{
+	String temp;
+	temp.m_str = str1 + str2.m_str;
+	return std::move(temp);
+}
+
+e2d::String e2d::operator+(const std::wstring &str1, const e2d::String &str2)
+{
+	String temp;
+	temp.m_str = str1 + str2.m_str;
+	return std::move(temp);
+}
+
+e2d::String &e2d::String::operator+=(const wchar_t x)
+{
+	m_str += x;
 	return *this;
 }
 
-String &String::operator+=(const wchar_t *str)
+e2d::String &e2d::String::operator+=(const wchar_t *str)
 {
-	if (!str) return *this;
-
-	int d_size = static_cast<int>(wcslen(str));
-	if (d_size == 0) return *this;
-
-	wchar_t *str_temp = new wchar_t[_size + d_size + 1];
-	if (_string) wcscpy_s(str_temp, _size + d_size + 1, _string);
-	wcscpy_s(str_temp + _size, d_size + 1, str);
-
-	delete[] _string;
-	_string = str_temp;
-	_size += d_size;
+	m_str += str;
 	return *this;
 }
 
-String &String::operator+=(const String &str)
+e2d::String &e2d::String::operator+=(const e2d::String &str)
 {
-	if (str._size == 0) return *this;
-
-	wchar_t *str_temp = new wchar_t[_size + str._size + 1];
-	if (_string) wcscpy_s(str_temp, _size + str._size + 1, _string);
-	wcscpy_s(str_temp + _size, str._size + 1, str._string);
-
-	delete[] _string;
-	_string = str_temp;
-	_size += str._size;
+	m_str += str.m_str;
 	return *this;
 }
 
-String & e2d::String::operator+=(const std::wstring &str)
+e2d::String & e2d::String::operator+=(const std::wstring &str)
 {
-	if (str.length() == 0) return *this;
-
-	wchar_t *str_temp = new wchar_t[_size + str.length() + 1];
-	if (_string) wcscpy_s(str_temp, _size + str.length() + 1, _string);
-	wcscpy_s(str_temp + _size, str.length() + 1, str.c_str());
-
-	delete[] _string;
-	_string = str_temp;
-	_size += static_cast<int>(str.length());
+	m_str += str;
 	return *this;
 }
 
-bool e2d::String::operator<(String const &str) const
+e2d::String::operator const wchar_t*() const
 {
-	for (int i = 0; i <= _size; i++)
-		if (_string[i] != str._string[i])
-			return _string[i] < str[i];
-	return false;
+	return m_str.c_str();
 }
 
-bool e2d::String::operator<=(String const &str) const
+e2d::String::operator bool() const
 {
-	for (int i = 0; i <= _size; i++)
-		if (_string[i] != str._string[i])
-			return _string[i] < str[i];
-	return true;
+	return getLength() != 0;
 }
 
-bool e2d::String::operator>(String const &str) const
+bool e2d::String::isEmpty() const
 {
-	for (int i = 0; i <= _size; i++)
-		if (_string[i] != str._string[i])
-			return _string[i] > str[i];
-	return false;
+	return m_str.empty();
 }
 
-bool e2d::String::operator>=(String const &str) const
+int e2d::String::getLength() const
 {
-	for (int i = 0; i <= _size; i++)
-		if (_string[i] != str._string[i])
-			return _string[i] > str[i];
-	return true;
+	return static_cast<int>(m_str.size());
 }
 
-unsigned int e2d::String::hash() const
+unsigned int e2d::String::getHash() const
 {
 	unsigned int hash = 0;
 
-	for (int i = 0; i < _size; i++)
+	for (int i = 0; i < getLength(); i++)
 	{
 		hash *= 16777619;
-		hash ^= (unsigned int)towupper(_string[i]);
+		hash ^= (unsigned int)towupper(m_str[i]);
 	}
-	return (hash);
+	return hash;
 }
 
-String e2d::operator+(const wchar_t ch, const String &str)
+std::wistream & e2d::operator>>(std::wistream &cin, e2d::String &str)
 {
-	return std::move((String(ch) + str));
-}
-
-String e2d::operator+(const wchar_t *str1, const String &str2)
-{
-	return std::move((String(str1) + str2));
-}
-
-String e2d::operator+(const String &str1, const String &str2)
-{
-	return std::move((String(str1) + str2));
-}
-
-String e2d::operator+(const std::wstring &str1, const String &str2)
-{
-	return std::move((String(str1) + str2));
-}
-
-std::wistream & e2d::operator>>(std::wistream &cin, String &str)
-{
-	const int limit_string_size = 4096;
-
-	str._string = new wchar_t[limit_string_size];
-
-	cin >> std::setw(limit_string_size) >> str._string;
-	str._size = static_cast<int>(wcslen(str._string));
+	cin >> str.m_str;
 	return cin;
 }
 
-
-String e2d::String::upper() const
+e2d::String e2d::String::toUpper() const
 {
 	String str(*this);
 
-	for (int i = 0; i < str._size; i++)
-		if (str._string[i] >= L'a' && str._string[i] <= L'z')
-			str._string[i] -= (L'a' - L'A');
+	for (int i = 0; i < getLength(); i++)
+		str[i] = towupper(str[i]);
 
 	return std::move(str);
 }
 
-String e2d::String::lower() const
+e2d::String e2d::String::toLower() const
 {
-	String str(*this);
+	e2d::String str(*this);
 
-	for (int i = 0; i < str._size; i++)
-		str._string[i] = towlower(str._string[i]);
+	for (int i = 0; i < getLength(); i++)
+		str[i] = towlower(str[i]);
 
 	return std::move(str);
 }
 
-String e2d::String::sub(int offset, int count) const
+int e2d::String::toInt() const
 {
-	if (_size == 0 || offset >= _size)
-		return std::move(String());
+	if (getLength() == 0)
+	{
+		return 0;
+	}
+	return _wtoi(m_str.c_str());
+}
+
+double e2d::String::toDouble() const
+{
+	if (getLength() == 0)
+	{
+		return 0.0;
+	}
+	return _wtof(m_str.c_str());
+}
+
+bool e2d::String::toBool() const
+{
+	if (getLength() == 0)
+	{
+		return false;
+	}
+
+	if (m_str.compare(L"0") == 0 || m_str.compare(L"false") == 0)
+	{
+		return false;
+	}
+	return true;
+}
+
+e2d::String e2d::String::subtract(int offset, int count) const
+{
+	String temp;
+	int length = getLength();
+
+	if (length == 0 || offset >= length)
+		return std::move(temp);
 
 	offset = offset >= 0 ? offset : 0;
 
-	if (count < 0 || (offset + count) > _size)
-		count = _size - offset;
+	if (count < 0 || (offset + count) > length)
+		count = length - offset;
 
-	String str_temp;
-	str_temp._string = new wchar_t[count + 1];
-
-	for (int i = 0; i < count; i++)
-		str_temp._string[i] = (_string + offset)[i];
-	str_temp._string[count] = 0;
-
-	return std::move(str_temp);
+	temp.m_str = m_str.substr(offset, count);
+	return std::move(temp);
 }
 
 int e2d::String::findFirstOf(const wchar_t ch) const
 {
-	for (int i = 0; i < _size; i++)
-		if (_string[i] == ch)
+	for (int i = 0; i < getLength(); i++)
+		if (m_str[i] == ch)
 			return i;
 
 	return -1;
@@ -401,24 +292,24 @@ int e2d::String::findLastOf(const wchar_t ch) const
 {
 	int index = -1;
 
-	for (int i = 0; i < _size; i++)
-		if (_string[i] == ch)
+	for (int i = 0; i < getLength(); i++)
+		if (m_str[i] == ch)
 			index = i;
 
 	return index;
 }
 
-String & e2d::String::append(const wchar_t ch)
+e2d::String & e2d::String::append(const wchar_t ch)
 {
 	return (*this) += ch;
 }
 
-String & e2d::String::append(const wchar_t * str)
+e2d::String & e2d::String::append(const wchar_t * str)
 {
 	return (*this) += str;
 }
 
-String & e2d::String::append(const String & str)
+e2d::String & e2d::String::append(const e2d::String & str)
 {
 	return (*this) += str;
 }
diff --git a/core/Manager/MusicManager.cpp b/core/Manager/MusicManager.cpp
index b9369dee..1758e993 100644
--- a/core/Manager/MusicManager.cpp
+++ b/core/Manager/MusicManager.cpp
@@ -24,7 +24,7 @@ bool e2d::MusicManager::add(const String & strFilePath)
 	}
 	else
 	{
-		UINT nRet = strFilePath.hash();
+		UINT nRet = strFilePath.getHash();
 		pPlayer = new Music();
 
 		if (pPlayer->_open(strFilePath))
@@ -45,7 +45,7 @@ e2d::Music * e2d::MusicManager::get(const String & strFilePath)
 	if (strFilePath.isEmpty())
 		return nullptr;
 
-	UINT nRet = strFilePath.hash();
+	UINT nRet = strFilePath.getHash();
 
 	if (getMusicList().end() != getMusicList().find(nRet))
 		return getMusicList()[nRet];
diff --git a/core/Node/Node.cpp b/core/Node/Node.cpp
index 99089c44..ab16c376 100644
--- a/core/Node/Node.cpp
+++ b/core/Node/Node.cpp
@@ -604,7 +604,7 @@ e2d::Node * e2d::Node::getChild(const String & name)
 {
 	WARN_IF(name.isEmpty(), "Invalid Node name.");
 
-	unsigned int hash = name.hash();
+	unsigned int hash = name.getHash();
 
 	for (auto child : m_vChildren)
 	{
@@ -621,7 +621,7 @@ std::vector<e2d::Node*> e2d::Node::getChildren(const String & name)
 
 	WARN_IF(name.isEmpty(), "Invalid Node name.");
 
-	unsigned int hash = name.hash();
+	unsigned int hash = name.getHash();
 
 	for (auto child : m_vChildren)
 		if (child->m_nHashName == hash && child->m_sName == name)
@@ -684,7 +684,7 @@ void e2d::Node::removeChildren(const String & childName)
 	}
 
 	// 计算名称 Hash 值
-	unsigned int hash = childName.hash();
+	unsigned int hash = childName.getHash();
 
 	size_t size = m_vChildren.size();
 	for (size_t i = 0; i < size; i++)
@@ -839,7 +839,7 @@ void e2d::Node::setName(const String & name)
 		// 保存节点名
 		m_sName = name;
 		// 保存节点 Hash 名
-		m_nHashName = name.hash();
+		m_nHashName = name.getHash();
 	}
 }
 
diff --git a/core/Node/Text.cpp b/core/Node/Text.cpp
index 7c7eea91..034ca3c6 100644
--- a/core/Node/Text.cpp
+++ b/core/Node/Text.cpp
@@ -103,7 +103,7 @@ void e2d::Text::onRender()
 	Renderer::getSolidColorBrush()->SetColor(D2D1::ColorF(m_pFont->m_Color, m_fDisplayOpacity));
 	Renderer::getRenderTarget()->DrawTextW(
 		m_sText,
-		UINT32(m_sText.length()),
+		static_cast<UINT32>(m_sText.getLength()),
 		m_pFont->_getTextFormat(),
 		D2D1::RectF(
 			0,
@@ -140,7 +140,7 @@ void e2d::Text::_initTextLayout()
 
 	HRESULT hr = Renderer::getIDWriteFactory()->CreateTextLayout(
 		m_sText,
-		UINT32(m_sText.length()),
+		static_cast<UINT32>(m_sText.getLength()),
 		m_pFont->_getTextFormat(),
 		m_bWordWrapping ? m_fWordWrappingWidth : 0,
 		0,
diff --git a/core/Tool/Data.cpp b/core/Tool/Data.cpp
index d095d184..679a8eef 100644
--- a/core/Tool/Data.cpp
+++ b/core/Tool/Data.cpp
@@ -3,12 +3,12 @@
 
 void e2d::Data::saveInt(const String & key, int value)
 {
-	::WritePrivateProfileString(L"Default", key, String::parse(value), File::getDefaultSavePath());
+	::WritePrivateProfileString(L"Default", key, String::toString(value), File::getDefaultSavePath());
 }
 
 void e2d::Data::saveFloat(const String & key, float value)
 {
-	::WritePrivateProfileString(L"Default", key, String::parse(value), File::getDefaultSavePath());
+	::WritePrivateProfileString(L"Default", key, String::toString(value), File::getDefaultSavePath());
 }
 
 void e2d::Data::saveString(const String & key, const String & value)
@@ -24,7 +24,7 @@ int e2d::Data::getInt(const String & key, int default)
 float e2d::Data::getFloat(const String & key, float default)
 {
 	wchar_t temp[32] = { 0 };
-	::GetPrivateProfileString(L"Default", key, String::parse(default), temp, 31, File::getDefaultSavePath());
+	::GetPrivateProfileString(L"Default", key, String::toString(default), temp, 31, File::getDefaultSavePath());
 	return std::stof(temp);
 }
 
diff --git a/core/Tool/File.cpp b/core/Tool/File.cpp
index c1efe892..d5d576b7 100644
--- a/core/Tool/File.cpp
+++ b/core/Tool/File.cpp
@@ -69,9 +69,9 @@ e2d::String e2d::File::getFileExtension(const String & filePath)
 	if (pos != -1)
 	{
 		// 截取扩展名
-		fileExtension = filePath.sub(pos, filePath.length());
+		fileExtension = filePath.subtract(pos);
 		// 转换为小写字母
-		fileExtension = fileExtension.lower();
+		fileExtension = fileExtension.toLower();
 	}
 
 	return fileExtension;
diff --git a/core/Tool/Music.cpp b/core/Tool/Music.cpp
index 995f3a5e..048a504b 100644
--- a/core/Tool/Music.cpp
+++ b/core/Tool/Music.cpp
@@ -40,7 +40,7 @@ Music::~Music()
 	_close();
 }
 
-bool Music::_open(LPWSTR strFileName)
+bool Music::_open(LPCWSTR strFileName)
 {
 	if (m_bOpened)
 	{
diff --git a/core/ecommon.h b/core/ecommon.h
index 1f796799..5252f74b 100644
--- a/core/ecommon.h
+++ b/core/ecommon.h
@@ -92,7 +92,6 @@ class String
 {
 public:
 	String();
-	String(const wchar_t);
 	String(const wchar_t *);
 	String(const String &);
 	String(const std::wstring &);
@@ -100,87 +99,55 @@ public:
 
 	~String();
 
-	String& operator=(const wchar_t *);
-	String& operator=(const String &);
-	String& operator=(const std::wstring &);
+	String& operator= (const wchar_t *);
+	String& operator= (const String &);
+	String& operator= (const std::wstring &);
 
-	bool operator==(const wchar_t *);
-	bool operator==(const String &);
-	bool operator==(const std::wstring &);
+	bool operator== (const wchar_t *);
+	bool operator== (const String &);
+	bool operator== (const std::wstring &);
 
-	bool operator!=(const wchar_t *);
-	bool operator!=(const String &);
-	bool operator!=(const std::wstring &);
+	bool operator!= (const wchar_t *);
+	bool operator!= (const String &);
+	bool operator!= (const std::wstring &);
 
-	wchar_t &operator[](int);
+	wchar_t &operator[] (int);
 
-	String operator+(const wchar_t);
-	String operator+(const wchar_t *);
-	String operator+(const String &);
-	String operator+(const std::wstring &);
+	String operator+ (const wchar_t);
+	String operator+ (const wchar_t *);
+	String operator+ (const String &);
+	String operator+ (const std::wstring &);
+
+	friend String operator+ (const wchar_t, const String &);
+	friend String operator+ (const wchar_t*, const String &);
+	friend String operator+ (const std::wstring &, const String &);
+
+	String& operator+= (const wchar_t);
+	String& operator+= (const wchar_t *);
+	String& operator+= (const String &);
+	String& operator+= (const std::wstring &);
 
 	template<typename T>
-	String operator+(const T value)
-	{
-		String str_temp(*this);
-
-		str_temp += value;
-		return std::move(str_temp);
-	}
-
-	String &operator +=(const wchar_t);
-	String &operator +=(const wchar_t *);
-	String &operator +=(const String &);
-	String &operator +=(const std::wstring &);
-
-	template<typename T>
-	String &operator +=(const T value)
+	String& operator<< (const T value)
 	{
 		std::wostringstream ss;
 		ss << value;
 		return (*this) += ss.str();
 	}
 
-	bool operator < (String const&) const;
-	bool operator <= (String const&) const;
-	bool operator > (String const&) const;
-	bool operator >= (String const&) const;
+	operator const wchar_t* () const;
+	operator bool () const;
 
-	operator wchar_t*() const { return _string; }
-	operator bool() const { return _size != 0; }
-
-	friend String operator+(const wchar_t, const String &);
-	friend String operator+(const wchar_t*, const String &);
-	friend String operator+(const String &, const String &);
-	friend String operator+(const std::wstring &, const String &);
-	template<typename T>
-	friend String operator+(const T &value, const String &str)
-	{
-		return std::move((String::parse(value) + str2));
-	}
-
-	friend std::wistream &operator>>(std::wistream &, String &);
+	friend std::wistream& operator>> (std::wistream &, String &);
 
 	// 判断字符串是否为空
-	bool isEmpty() const { return _size == 0; }
+	bool isEmpty() const;
 
 	// 获取字符串长度
-	int length() const { return _size; }
+	int getLength() const;
 
-	// 获取大写字符串
-	String upper() const;
-
-	// 获取小写字符串
-	String lower() const;
-
-	// 获取裁剪字符串
-	String sub(int offset, int count = -1) const;
-
-	// 获取字符串中第一个特定字符的下标
-	int findFirstOf(const wchar_t ch) const;
-
-	// 获取字符串中最后一个特定字符的下标
-	int findLastOf(const wchar_t ch) const;
+	// 获取该字符串的散列值
+	unsigned int getHash() const;
 
 	// 后接字符
 	String &append(const wchar_t ch);
@@ -198,25 +165,41 @@ public:
 		return (*this) += value;
 	}
 
-	// 获取该字符串的散列值
-	unsigned int hash() const;
+	// 获取裁剪字符串
+	String subtract(int offset, int count = -1) const;
 
-	// 将模板类型转化为字符串
+	// 获取字符串中第一个特定字符的下标
+	int findFirstOf(const wchar_t ch) const;
+
+	// 获取字符串中最后一个特定字符的下标
+	int findLastOf(const wchar_t ch) const;
+
+	// 获取大写字符串
+	String toUpper() const;
+
+	// 获取小写字符串
+	String toLower() const;
+
+	// 将字符串转化为 int 型
+	int toInt() const;
+
+	// 将字符串转化为 double 型
+	double toDouble() const;
+
+	// 将字符串转化为 bool 型
+	bool toBool() const;
+
+	// 将任意类型转化为字符串
 	template<typename T>
-	static String parse(const T value)
+	static String toString(const T value)
 	{
-		String str;
-
 		std::wostringstream ss;
 		ss << value;
-		str += ss.str();
-
-		return std::move(str);
+		return ss.str();
 	}
 
 private:
-	wchar_t *_string;
-	int _size;
+	std::wstring m_str;
 };
 
 
diff --git a/core/etools.h b/core/etools.h
index 94275294..4dd8f04a 100644
--- a/core/etools.h
+++ b/core/etools.h
@@ -252,7 +252,7 @@ protected:
 
 	virtual ~Music();
 
-	bool _open(LPWSTR strFileName);
+	bool _open(LPCWSTR strFileName);
 
 	void _close();