标签：style blog io ar color os 使用 sp for
为了提高duilib创建布局控件的效率，在LuaDui项目中使用rapidxml解析器替换了duilib库自带的xml解析器。
duilib使用unicode编译，所以rapidxml需要解析unicode xml字符串。
使用rapidxml解析unicode字符串很简单，只需在rapidxml的模板参数中设置为TCHAR即可，所以定义以下类型方便使用。
#include <rapidxml/rapidxml.hpp> typedef rapidxml::xml_document<TCHAR> XmlDoc; typedef rapidxml::xml_node<TCHAR> XmlNode; typedef rapidxml::xml_attribute<TCHAR> XmlAttr;
在使用过程中发现了解析xml中的中文字符出现bug，解析如下xml会出现问题抛出异常。
<?xml version="1.0" encoding="UTF-8"?>
<Window caption="0,0,0,30" sizebox="5,5,5,5" mininfo="480,360" defaultfontcolor="#ff010000" width="600" height="480">
<Font name="微软雅黑" size="12" bold="false"/>
<VerticalLayout bkcolor="#ff019bd0" inset="1,1,1,1" bordersize="1" bordercolor="#FF010000">
<HorizontalLayout height="30" inset="5,0,0,0">
<Label name="标题" text="调试窗口" textcolor="#FFFFFFFF"></Label>
<Control />
<Button name="minbtn" width="40" height="22" text="最小化" bkcolor="#ff3fd536">
<Event click="DebugUIEvent.minBtnClick" />
</Button>
<Button name="closebtn" width="47" height="22" text="关闭" bkcolor="#ffef2f4d">
<Event click="DebugUIEvent.closeBtnClick" />
</Button>
</HorizontalLayout>
<VerticalLayout bkcolor="#66ffffff">
</VerticalLayout>
</VerticalLayout>
</Window>
断点时发现在解析 text="最小化" 属性时出现问题，解析text值的时候把后面的内容全部当做text的属性值，无法再往下解析了。
最后终于找到了问题所在，rapidxml为提高解析效率，定义了如下的表：
template<int Dummy>
struct lookup_tables
{
static const unsigned char lookup_whitespace[256]; // Whitespace table
static const unsigned char lookup_node_name[256]; // Node name table
static const unsigned char lookup_text[256]; // Text table
static const unsigned char lookup_text_pure_no_ws[256]; // Text table
static const unsigned char lookup_text_pure_with_ws[256]; // Text table
static const unsigned char lookup_attribute_name[256]; // Attribute name table
static const unsigned char lookup_attribute_data_1[256]; // Attribute data table with single quote
static const unsigned char lookup_attribute_data_1_pure[256]; // Attribute data table with single quote
static const unsigned char lookup_attribute_data_2[256]; // Attribute data table with double quotes
static const unsigned char lookup_attribute_data_2_pure[256]; // Attribute data table with double quotes
static const unsigned char lookup_digits[256]; // Digits
static const unsigned char lookup_upcase[256]; // To uppercase conversion table for ASCII characters
};
来识别xml中的标志符，在进行查找的时候直接通过数组直接找到使用了
如下操作：
internal::lookup_tables<0>::lookup_text_pure_no_ws[static_cast<unsigned char>(ch)];
但在unicode下static_cast<unsigned char>(ch)的ch是wchar占两个字节直接转换为unsigned char会出现判断出错问题。所以要在rapidxml中解析unicode需要修改rapidxml代码：
// Detect whitespace character
struct whitespace_pred
{
static unsigned char test(Ch ch)
{
if(ch<=255)
return internal::lookup_tables<0>::lookup_whitespace[static_cast<unsigned char>(ch)];
else
return 0;
}
};
// Detect node name character
struct node_name_pred
{
static unsigned char test(Ch ch)
{
if(ch<=255)
return internal::lookup_tables<0>::lookup_node_name[static_cast<unsigned char>(ch)];
else
return 1;
}
};
// Detect attribute name character
struct attribute_name_pred
{
static unsigned char test(Ch ch)
{
if(ch<=255)
return internal::lookup_tables<0>::lookup_attribute_name[static_cast<unsigned char>(ch)];
else
return 1;
}
};
// Detect text character (PCDATA)
struct text_pred
{
static unsigned char test(Ch ch)
{
if(ch<=255)
return internal::lookup_tables<0>::lookup_text[static_cast<unsigned char>(ch)];
else
return 1;
}
};
// Detect text character (PCDATA) that does not require processing
struct text_pure_no_ws_pred
{
static unsigned char test(Ch ch)
{
if(ch<=255)
return internal::lookup_tables<0>::lookup_text_pure_no_ws[static_cast<unsigned char>(ch)];
else
return 1;
}
};
// Detect text character (PCDATA) that does not require processing
struct text_pure_with_ws_pred
{
static unsigned char test(Ch ch)
{
if(ch<=255)
return internal::lookup_tables<0>::lookup_text_pure_with_ws[static_cast<unsigned char>(ch)];
else
return 1;
}
};
// Detect attribute value character
template<Ch Quote>
struct attribute_value_pred
{
static unsigned char test(Ch ch)
{
if (Quote == Ch(‘\‘‘))
if(ch<=255)
return internal::lookup_tables<0>::lookup_attribute_data_1[static_cast<unsigned char>(ch)];
else
return 1;
if (Quote == Ch(‘\"‘))
if(ch<=255)
return internal::lookup_tables<0>::lookup_attribute_data_2[static_cast<unsigned char>(ch)];
else
return 1;
return 0; // Should never be executed, to avoid warnings on Comeau
}
};
// Detect attribute value character
template<Ch Quote>
struct attribute_value_pure_pred
{
static unsigned char test(Ch ch)
{
if (Quote == Ch(‘\‘‘))
if(ch<=255)
return internal::lookup_tables<0>::lookup_attribute_data_1_pure[static_cast<unsigned char>(ch)];
else
return 1;
if (Quote == Ch(‘\"‘))
if(ch<=255)
return internal::lookup_tables<0>::lookup_attribute_data_2_pure[static_cast<unsigned char>(ch)];
else
return 1;
return 0; // Should never be executed, to avoid warnings on Comeau
}
};
标签：style blog io ar color os 使用 sp for
原文地址：http://www.cnblogs.com/zentel/p/4162602.html
