C# Filter XML for Attribute Name

Question

this is my xml file

<SW.Blocks.CompileUnit ID="3" CompositionName="CompileUnits">
<AttributeList>
    <NetworkSource>
        <FlgNet xmlns="http://www.siemens.com/automation/Openness/SW/NetworkSource/FlgNet/v2">
            <Parts>
                <Access Scope="GlobalVariable" UId="21">
                    <Symbol>
                        <Component Name="PlantConfigData" />
                        <Component Name="C001" />
                        <Component Name="command" />
                        <Component Name="conveyorGUID" />
                    </Symbol>
                </Access>
                <Access Scope="GlobalVariable" UId="22">
                    <Symbol>
                        <Component Name="PlantConfigData" />
                        <Component Name="C001" />
                    </Symbol>
                </Access>
                <Call UId="23">
                    <CallInfo Name="Conveyor Type C" BlockType="FB">
                        <Instance Scope="GlobalVariable" UId="24">
                            <Component Name="Conveyor Type C_DB" />
                        </Instance>
                        <Parameter Name="GUID" Section="Input" Type="String" />
                        <Parameter Name="Auto_Hand" Section="Input" Type="Bool" />
                        <Parameter Name="Notaus" Section="Input" Type="Bool" />
                        <Parameter Name="Input" Section="Input" Type="typeConveyorDrive" />
                        <Parameter Name="out1" Section="Output" Type="Bool" />
                    </CallInfo>
                </Call>
            </Parts>
            <Wires>
                <Wire UId="29">
                    <OpenCon UId="25" />
                    <NameCon UId="23" Name="en" />
                </Wire>
                <Wire UId="30">
                    <IdentCon UId="21" />
                    <NameCon UId="23" Name="GUID" />
                </Wire>
                <Wire UId="31">
                    <OpenCon UId="26" />
                    <NameCon UId="23" Name="Auto_Hand" />
                </Wire>
                <Wire UId="32">
                    <OpenCon UId="27" />
                    <NameCon UId="23" Name="Notaus" />
                </Wire>
                <Wire UId="33">
                    <IdentCon UId="22" />
                    <NameCon UId="23" Name="Input" />
                </Wire>
                <Wire UId="34">
                    <NameCon UId="23" Name="out1" />
                    <OpenCon UId="28" />
                </Wire>
            </Wires>
        </FlgNet>
    </NetworkSource>
    <ProgrammingLanguage>FBD</ProgrammingLanguage>
</AttributeList>
<ObjectList>
    <MultilingualText ID="4" CompositionName="Comment">
        <ObjectList>
            <MultilingualTextItem ID="5" CompositionName="Items">
                <AttributeList>
                    <Culture>de-DE</Culture>
                    <Text>Bausteinaufruf C001 GUID?</Text>
                </AttributeList>
            </MultilingualTextItem>
        </ObjectList>
    </MultilingualText>
    <MultilingualText ID="6" CompositionName="Title">
        <ObjectList>
            <MultilingualTextItem ID="7" CompositionName="Items">
                <AttributeList>
                    <Culture>de-DE</Culture>
                    <Text>C001</Text>
                </AttributeList>
            </MultilingualTextItem>
        </ObjectList>
    </MultilingualText>
</ObjectList>
</SW.Blocks.CompileUnit>

I want to filter all XElements with LINQ, which have the attribute name "ID" (called XName?!). I don't care about the value. I need to write my own values (like 1....10, for the next call 11...20) in all ID elements, because they have to be unique.

So there is my main xml, I will call the xml above, change values, and copy it in my main xml. Depends on my device count.

I saw a lot of examples for filtering after value, but not for the attribute name.

My code until know:

var id =
                from el in root.Descendants(nse_type + "SW.Blocks.CompileUnit")
                where // I need to filter?
                select el;

Maybe a better way is get all XElements with LINQ and filter in foreach() to change values with attribute name "ID"?

I'm a beginner, maybe its not that complicated. Thank you very much!

Answer 1

Well, if you want to get all elements that have ID attribute, you can do the following:

var elements= from el in root.Descendants()
              where el.Attribute("ID") != null //This will check if the attribute exist or not              
              select el;

Now you can iterate over the result to update the attribute:

int i=0;
foreach (XElement e in elements)
{
  e.Attribute("ID").Value=(i++).ToString();
}