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我正在尝试使用 Linq to Xml 过滤 xmldata，问题是我无法使用 XElement.Elements(Xname) 方法获取元素，但是在使用 XElement.Desendents(Xname) 方法时它工作正常但显示所有元素我不想要。我想要它应该显示所有元素和属性，其元素和属性名称在两个文本框中传递。

XML:

<?xml version="1.0" ?> 
<Summary AvailableRules="71000" SelectedRules="445" OmittedRules="6887">
  <BBCE AvailableRules="69" SelectedRules="4" OmittedRules="65">
    <SelectedRules>
      <Rule RuleID="jc_0201" Priority="Strongly Recommended" /> 
      <Rule RuleID="jc_0211" Priority="Strongly Recommended" /> 
      <Rule RuleID="jc_0221" Priority="Strongly Recommended" /> 
      <Rule RuleID="jc_0231" Priority="Strongly Recommended" /> 
    </SelectedRules>
    <OmittedRules>
      <Rule RuleID="ar_0001" Priority="Mandatory" /> 
      <Rule RuleID="ar_0002" Priority="Mandatory" /> 
      <Rule RuleID="db_0143_a" Priority="Strongly Recommended" /> 
      <Rule RuleID="db_0143_b" Priority="Strongly Recommended" /> 
      <Rule RuleID="jc_0311" Priority="Mandatory" /> 
      <Rule RuleID="jc_0321" Priority="Mandatory" /> 
      <Rule RuleID="jc_0331" Priority="Mandatory" /> 
      <Rule RuleID="jc_0341" Priority="Mandatory" /> 
      <Rule RuleID="jc_0011" Priority="Strongly Recommended" /> 
      <Rule RuleID="jc_0021" Priority="Strongly Recommended" /> 
      <Rule RuleID="na_0004_a" Priority="Recommended" /> 
      <Rule RuleID="na_0004_b" Priority="Recommended" /> 
      <Rule RuleID="db_0043" Priority="Strongly Recommended" /> 
      <Rule RuleID="db_0042" Priority="Strongly Recommended" /> 
      <Rule RuleID="na_0005" Priority="Strongly Recommended" /> 
      <Rule RuleID="jc_0081" Priority="Recommended" /> 
      <Rule RuleID="jm_0002" Priority="Mandatory" /> 
      <Rule RuleID="db_0142" Priority="Strongly Recommended" /> 
      <Rule RuleID="jc_0061" Priority="Recommended" /> 
      <Rule RuleID="db_0146" Priority="Strongly Recommended" /> 
      <Rule RuleID="db_0140" Priority="Recommended" /> 
      <Rule RuleID="jm_0013" Priority="Strongly Recommended" /> 
      <Rule RuleID="db_0032" Priority="Strongly Recommended" /> 
      <Rule RuleID="db_0141" Priority="Strongly Recommended" /> 
      <Rule RuleID="jc_0171" Priority="Strongly Recommended" /> 
      <Rule RuleID="jm_0010" Priority="Strongly Recommended" /> 
      <Rule RuleID="jc_0281" Priority="Strongly Recommended" /> 
      <Rule RuleID="na_0008" Priority="Recommended" /> 
      <Rule RuleID="na_0009" Priority="Strongly Recommended" /> 
    </OmittedRules>
  </BBCE>
</Summary>

C#代码：

var button = sender as Button;
var parent = button.Parent as FrameworkElement;

//(Textbox to take element`s name)
var textBox = parent.FindName("textbox1") as TextBox;

var textbl = parent.FindName("abc") as TextBlock;
var com = parent.FindName("cbox1") as ComboBox;

//(Textbox to take ATTRIBUTE`s name)  
var textBox1 = parent.FindName("textbox2") as TextBox;

XElement ele = XElement.Load(txtFileName.Text);

//working with Xelement.desendents it works fine
var fil = from item in ele.Elements(textbl.Text)
          select item.Element(textBox.Text).Attribute(textBox1.Text);

foreach (var f in fil)
{
    Label lb = new Label();
    lb.Content = f;
    canvas1.Children.Add(lb);
}

我观察到的是，仅使用 BBCE 元素时它可以正常工作，但是在添加带有属性（元素方法）的摘要元素时将无法正常工作。

我错过了什么吗？

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1 回答 1

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Elements(name)方法返回节点的子元素。Descendants(name)方法返回节点的后代元素。那是预期的行为。

So, when you are calling ele.Elements(textbl.Text) then search will occur only between direct children of ele elements. When you are loading file via XElement ele = XElement.Load, then ele element will be root element of xml. I.e. <Summary> element in your case. It has single child <BBCE>. That's why you can find only <BBCE> when you are using Elements() method to search.

Descendants() method in your case will search for any element in document, except <Summary> node itself.

于 2013-02-22T06:35:06.507 回答