LINQ读取复杂的XML

Question

LINQ to read XML

Below is my *.xml file having two sections:

---

<sections>
    <section guid="112ff6b8-2609-4d19-b774-33ab951ee66a" last_change="1970-01-01T00:00:00.000" action="added"
             name="Concrete sections, Rectangle, 150x300" type="custom" fd-mat="3" fd_name_code="Concrete sections"
             fd_name_type="Rectangle" fd_name_size="150x300">
        <region_group>
            <region>
                <contour>
                    <edge type="line">
                        <point x="-0.075" y="-0.15" z="0"></point>
                        <point x="0.075" y="-0.15" z="0"></point>
                        <normal x="0" y="1" z="0"></normal>
                    </edge>
                    <edge type="line">
                        <point x="0.075" y="-0.15" z="0"></point>
                        <point x="0.075" y="0.15" z="0"></point>
                        <normal x="-1" y="0" z="0"></normal>
                    </edge>
                    <edge type="line">
                        <point x="0.075" y="0.15" z="0"></point>
                        <point x="-0.075" y="0.15" z="0"></point>
                        <normal x="0" y="-1" z="0"></normal>
                    </edge>
                    <edge type="line">
                        <point x="-0.075" y="0.15" z="0"></point>
                        <point x="-0.075" y="-0.15" z="0"></point>
                        <normal x="1" y="0" z="0"></normal>
                    </edge>
                </contour>
            </region>
        </region_group>
        <end></end>
    </section>
    <section guid="98948ace-afb2-400d-9d96-752f5fce40c4" last_change="1970-01-01T00:00:00.000" action="added"
             name="Concrete sections, Rectangle, 300x600" type="custom" fd-mat="3" fd_name_code="Concrete sections"
             fd_name_type="Rectangle" fd_name_size="300x600">
        <region_group>
            <region>
                <contour>
                    <edge type="line">
                        <point x="-0.15" y="-0.3" z="0"></point>
                        <point x="0.15" y="-0.3" z="0"></point>
                        <normal x="0" y="1" z="0"></normal>
                    </edge>
                    <edge type="line">
                        <point x="0.15" y="-0.3" z="0"></point>
                        <point x="0.15" y="0.3" z="0"></point>
                        <normal x="-1" y="0" z="0"></normal>
                    </edge>
                    <edge type="line">
                        <point x="0.15" y="0.3" z="0"></point>
                        <point x="-0.15" y="0.3" z="0"></point>
                        <normal x="0" y="-1" z="0"></normal>
                    </edge>
                    <edge type="line">
                        <point x="-0.15" y="0.3" z="0"></point>
                        <point x="-0.15" y="-0.3" z="0"></point>
                        <normal x="1" y="0" z="0"></normal>
                    </edge>
                </contour>
            </region>
        </region_group>
        <end></end>
    </section>

As the results I wish to select (guid, fd_name_size) from the above two sections, as shown below

112ff6b8-2609-4d19-b774-33ab951ee66a, 150x300

98948ace-afb2-400d-9d96-752f5fce40c4, 300x600

---

Here is my C# code

        string a1 = "will be guid"; string a2 = "will be fd_name_size"; // to test

        var secBC = from lv1 in xDoc.Descendants("section")
                    select new
                    {
                        Header = lv1.Attribute("guid").Value
                       // How to select "fd_name_size" ????
                    };

        foreach (var lv1 in secBC)
        {
            a1 = lv1.Header;
        }

I get only the 'guid' (as a1) but do not know how also to select 'fd_name_size'. Please help :o)

---

Answer 1

lv1.Attribute("fd_name_size").Value

这应该够了吧。

Answer 2

You can do similarly you did it for "guid".

var secBC = from lv1 in xdoc.Descendants("section")
                    select new
                    {
                        Header = lv1.Attribute("guid").Value,
                        NameSize= lv1.Attribute("fd_name_size").Value                            
                    };

        foreach (var lv1 in secBC)
        {
             a1 = lv1.Header;
             a2 = lv1.NameSize;
        }

Answer 3

Thank you very much :o) The next block of *.xml data “complex_section” include also “section 'guid'”, but not 'fd_name_size', therefore NullReferenceException occurred. The *.xml above is just a part of a long *.xml file. The C #codes below give me the correct values. I love LinQ to XML. Thanks :o)

        List<string> guID = new List<string>();
        List<string> name = new List<string>();
        var secBC = from lv1 in xDoc.Descendants("section")
                    .Where(lv1 => (string)lv1.Attribute("fd_name_size") != null)
                    select new
                    {
                        Header = lv1.Attribute("guid").Value,
                        NameSize = lv1.Attribute("fd_name_size").Value  
                    };

        foreach (var lv1 in secBC)
        {
            guID.Add(lv1.Header);   // [0] 112ff6b8-2609-4d19-b774-33ab951ee66a, OK 
                                    // [1] 98948ace-afb2-400d-9d96-752f5fce40c4, OK

            name.Add(lv1.NameSize); // [0] 150x300, OK 
                                    // [1] 300x600, OK
        }