在现代软件开发中，XML作为一种数据交换格式被广泛应用。SequelMax.NET是一个高效的XML解析引擎，它基于C++的SequelMax库进行移植和修改。不同于传统的DOM解析方式，SequelMax.NET在解析XML时不会构建内部DOM树，而是在解析过程中调用注册的委托。此外，SequelMax.js版本也在开发计划中。
本文将通过一个示例来展示如何使用SequelMax.NET解析XML数据。示例中的XML数据如下：
<?xml version="1.0" encoding="UTF-8" ?>
<Employees>
<Employee EmployeeID="1286" SupervisorID="666">
<Name>Amanda Dion</Name>
<Salary>2200</Salary>
<Gender>Female</Gender>
</Employee>
<Employee EmployeeID="1287" SupervisorID="666">
<Name>John Smith</Name>
<Salary>3200</Salary>
<Gender>Male</Gender>
</Employee>
<Employee EmployeeID="1288" SupervisorID="666">
<Name>Sheldon Cohn</Name>
<Salary>5600</Salary>
<Gender>Male</Gender>
</Employee>
</Employees>
为了存储解析后的XML数据，定义了一个C#类Employee，如下所示：
class Employee
{
public int EmployeeID;
public int SupervisorID;
public string Name;
public string Gender;
public double Salary;
public string Comment;
}
接下来，将展示如何使用SequelMax.NET注册解析事件并读取XML数据。首先，需要注册一个开始元素的委托，用于创建新的Employee实例并初始化其属性：
static bool ReadDoc(string file, List<Employee> list)
{
SequelMaxNet.Document doc = new SequelMaxNet.Document();
doc.RegisterStartElementDelegate("Employees|Employee", (elem) =>
{
Employee emp = new Employee();
emp.EmployeeID = elem.Attr("EmployeeID").GetInt32(0);
emp.SupervisorID = elem.Attr("SupervisorID").GetInt32(0);
list.Add(emp);
});
doc.RegisterEndElementDelegate("Employees|Employee|Name", (text) =>
{
list[list.Count - 1].Name = text;
});
doc.RegisterEndElementDelegate("Employees|Employee|Gender", (text) =>
{
list[list.Count - 1].Gender = text;
});
doc.RegisterEndElementDelegate("Employees|Employee|Salary", (text) =>
{
Double.TryParse(text, out list[list.Count - 1].Salary);
});
doc.RegisterCommentDelegate("Employees|Employee", (text) =>
{
list[list.Count - 1].Comment = text;
});
return doc.Open(file);
}
解析完成后，可以使用以下代码将解析结果输出到控制台：
static void DisplayDoc(List<Employee> list)
{
for (int i = 0; i < list.Count; ++i)
{
Console.WriteLine("Name: " + list[i].Name);
Console.WriteLine("EmployeeID: " + list[i].EmployeeID);
Console.WriteLine("SupervisorID: " + list[i].SupervisorID);
Console.WriteLine("Gender: " + list[i].Gender);
Console.WriteLine("Salary: " + list[i].Salary);
if (!string.IsNullOrEmpty(list[i].Comment))
Console.WriteLine("Comment: " + list[i].Comment);
Console.WriteLine();
}
}
Name: Amanda Dion
EmployeeID: 1286
SupervisorID: 666
Gender: Female
Salary: 2200
Comment: Hardworking employee!
Name: John Smith
EmployeeID: 1287
SupervisorID: 666
Gender: Male
Salary: 3200
Comment: Hardly working employee!
Name: Sheldon Cohn
EmployeeID: 1288
SupervisorID: 666
Gender: Male
Salary: 5600