Question

我的XML文件就像..

<?xml version="1.0" encoding="utf-8" ?> 
<Controls>
      <Control ToValidate="0" ControlID="cmbTrialType" ControlType="FormControl"   EngineValueID="" Enabled="0" Visible="1" Single="1" Input="1" Value="Superiority" ListInitValues="Superiority" FormulaEntered="" Caption="" IsValid="1" DecimalPlaces="" /> 
      <Control ToValidate="1" ControlID="cmbTrialType" ControlType="FormControl" EngineValueID="" Enabled="1" Visible="0" Single="1" Input="1" Value="Superiority" ListInitValues="Superiority" FormulaEntered="" Caption="" IsValid="1" DecimalPlaces="" /> 
</Controls>

我需要读取此xml并执行以下操作

如果validate属性为prsent，请检查其值，即0或1并执行某些操作
如果验证属性不是prsent，则执行任何操作，即不检查其值。

我尝试编写以下功能，但其性能成本更高。

public void LoadXML(String xmlFileName)
        {
            Stopwatch sw = new Stopwatch();
            sw.Start(); 
            string refernceFileName = xmlFileName;
            XmlTextReader textReader = new XmlTextReader(refernceFileName);
            //int count = 0;
            // Read until end of file
            while (textReader.Read())
            {
                XmlNodeType nType = textReader.NodeType;

                // if node type is an element
                if (nType == XmlNodeType.Element)
                {
                    if (textReader.Name.Equals("Control"))
                    {
                        if (textReader.AttributeCount >= 1)
                        {
                               String val = string.Empty;
                               val = textReader.GetAttribute("Visible");

                               if (!(val == null || val.Equals(string.Empty)))
                               {
                                   int choice = Int32.Parse(val);
                                   switch (choice)
                                   {
                                       case 0: Console.WriteLine("Visible");
                                           break;
                                       case 1: Console.WriteLine("Not Visible");
                                           break;
                                   }
                               }
                        }
                    }
                }
            }
            sw.Stop();
            Console.WriteLine("Elapsed={0}", sw.Elapsed);
            //Console.WriteLine(count);
        }

Answer 1

见：

var xml = XElement.Load(@"path\to\your\xml\file");

var elements = xml.Elements("Control").Where(e => e.Attribute("ToValidate") != null);

foreach(var element in elements)
{
    var validateAttribute = element.Attribute("ToValidate").Value;
    if (validateAttribute == "0")
    {
        // something if invalid
    }
    else 
    {
        // something if valid
    }
}

如果您的目的只是处理仅存在ToValidate="1"或ToValidate="0"的元素。您可以考虑使用它：

var elements = xml.Elements("Control").Where(e => e.Attribute("ToValidate") != null && 
                                                  e.Attribute("ToValidate").Value == "1");

Answer 2

1.执行检查操作

创建控件但不验证它不检查其值

希望你通过课程

Answer 3

试试这个：

var elements = xml.Elements("Control").Where(
    e => e.Attribute("ToValidate") != null 
    && e.Attribute("ToValidate").Value == "1"
);

最大限度地降低读取XML的性能成本

3 个答案: