使用 XDocument 循环遍历节点的所有属性

Question

I have the following xml that stores table definations. How can I loop through each column of the passed tablename (only one occurrence of each table) and their attributes using XDocument (C# 3.5)

Ex: If user passes CurrencySummary, I want to read each column and all it's attributes like HeaderDescription, HeaderName etc.

<?xml version="1.0" encoding="utf-8" ?>
<TableDef>
  <CurrencySummary>
    <Column Name="Currency" HeaderDescription="Currency" HeaderName="Currency" ColumnType="TableColumnType.Text" IsHidden = "false" Position="0" Width="100" />
    <Column Name="ParamortizedValue" HeaderDescription="Par/amortized value" HeaderName="paramortizedvalue" ColumnType="TableColumnType.Number" IsHidden = "false" Position="1" Width="200" />
    <Column Name="PercentBondTotal" HeaderDescription="% of bond total" HeaderName="percentbondtotal" ColumnType="TableColumnType.Number" IsHidden = "false" Position="2" Width="150" />
  </CurrencySummary>
  <CallSchedule>
    <Column Name="Calldate" HeaderDescription="Call date" HeaderName="Calldate" ColumnType="TableColumnType.Text" IsHidden = "false" Position="0" Width="100" />
    <Column Name="Issue" HeaderDescription="Issue" HeaderName="Issue" ColumnType="TableColumnType.Text" IsHidden = "false" Position="1" Width="100" />
    <Column Name="ParamortizedValue" HeaderDescription="Par/amortized value" HeaderName="paramortizedvalue" ColumnType="TableColumnType.Number" IsHidden = "false" Position="2" Width="200" />
    <Column Name="PercentBondTotal" HeaderDescription="% of bond total" HeaderName="percentbondtotal" ColumnType="TableColumnType.Number" IsHidden = "false" Position="3" Width="150" />
  </CallSchedule>
</TableDef>

I am trying to achieve this by: (edited: as per Henk's suggestion)

var doc = XDocument.Load("TableDefinations.xml");
var cols = doc.Descendants("CurrencySummary").First();
foreach (var col in cols.Elements())
{
    foreach (XAttribute at in col.Attributes())
    {
        //do something with the at.Name and at.Value
    }
}

Is this is efficient way or if there is anything better than this?

Answer 1

It depends a little on how many <CurrencySummary> s there are and if their place matters.

var summ = doc.Descendants("CurrencySummary").First();

foreach (var col in summ.Elements())
   ...

Answer 2

OP not on.Net 4, so not using SelectMany , if Single() not.Net 4.0 substitute with First()

Looks like you there should be only one "CurrencySummary" so...

var doc = XDocument.Load("TableDefinations.xml");
foreach(XElement col in doc.Descendants("CurrencySummary").Single().Elements())
{
    foreach(XAttribute at in col.Attributes())
    {
        at...
    }
}

Will iterate through all the attributes of all the elements in the one and only CurrencySummary element, anywhere in the TableDefninations.xml.