Read XML Attribute

[vrbahrami]

Hi guys I'm a beginner, i have a problem to read a attribute from a XML file, How can i read sub attribute from repeated attribute?

<weatherdata>
<location>
<name>Tehran</name>
<type/>
<country>IR</country>
<timezone>12600</timezone>
<location altitude="0" latitude="35.74" longitude="51.58" geobase="geonames" geobaseid="112931"/>
</location>
<credit/>
<meta>
<lastupdate/>
<calctime>0</calctime>
<nextupdate/>
</meta>
<sun rise="2020-10-05T02:31:49" set="2020-10-05T14:12:01"/>

<forecast>

<time from="2020-10-05T15:00:00" to="2020-10-05T18:00:00">
<symbol number="803" name="broken clouds" var="04n"/>
<precipitation probability="0.45"/>
<windDirection deg="37" code="NE" name="NorthEast"/>
<windSpeed mps="0.58" unit="m/s" name="Calm"/>
<temperature unit="celsius" value="17.2" min="17.2" max="18.46"/>
<feels_like value="15.9" unit="celsius"/>
<pressure unit="hPa" value="1021"/>
<humidity value="48" unit="%"/>
<clouds value="broken clouds" all="57" unit="%"/>
<visibility value="10000"/>
</time>

<time from="2020-10-05T18:00:00" to="2020-10-05T21:00:00">
<symbol number="500" name="light rain" var="10n"/>
<precipitation probability="0.36" unit="3h" value="0.2" type="rain"/>
<windDirection deg="45" code="NE" name="NorthEast"/>
<windSpeed mps="2" unit="m/s" name="Light breeze"/>
<temperature unit="celsius" value="17.29" min="17.29" max="17.64"/>
<feels_like value="14.75" unit="celsius"/>
<pressure unit="hPa" value="1020"/>
<humidity value="44" unit="%"/>
<clouds value="broken clouds" all="60" unit="%"/>
<visibility value="10000"/>
</time>

<time from="2020-10-05T21:00:00" to="2020-10-06T00:00:00">
<symbol number="803" name="broken clouds" var="04n"/>
<precipitation probability="0.08"/>
<windDirection deg="109" code="ESE" name="East-southeast"/>
<windSpeed mps="0.9" unit="m/s" name="Calm"/>
<temperature unit="celsius" value="16.72" min="16.72" max="16.77"/>
<feels_like value="14.72" unit="celsius"/>
<pressure unit="hPa" value="1020"/>
<humidity value="42" unit="%"/>
<clouds value="broken clouds" all="58" unit="%"/>
<visibility value="10000"/>
</time>

</forecast>
</weatherdata>

I use this code but allways return (name) from first block

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Dim e1 As String
        Dim m_xmld As XmlDocument = New XmlDocument
        m_xmld.Load("forecast.xml")
        Dim loc_node As XmlNode = m_xmld.SelectSingleNode("weatherdata/forecast/time/windSpeed")
        e1 = (loc_node.Attributes("name").Value)
        MessageBox.Show(e1)
    End Sub

How Can Read (Name) Attribute from 2nd Block or 3rd Block?

[techgnome]

Well, if SelectSingleNode returns a single node, and you want more than one node... what do you think you should do?
Select multiple nodes... loop through them, and then get the attribute from each node.

-tg

hint: look up SelectNodes

[vrbahrami]

sorry I'm bigger and i don't understand your solution
For Example feels_like value repeated on 3 block, how can read feels_like value on block 2 or 3?


Attachment 178939

[dbasnett]

These sorts of things are better handled with XElement IMHO. I've commented out the .Load and used a literal for testing. What a 'block' exactly is I don't know. Try this code.

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim wd As XElement
        'to load from a URI uncomment this and get rid of literal
        ' wd = XElement.Load("forecast.xml")
        '
        'a Literal for testing, delete when using .Load
        wd = <weatherdata>
                 <location>
                     <name>Tehran</name>
                     <type/>
                     <country>IR</country>
                     <timezone>12600</timezone>
                     <location altitude="0" latitude="35.74" longitude="51.58" geobase="geonames" geobaseid="112931"/>
                 </location>
                 <credit/>
                 <meta>
                     <lastupdate/>
                     <calctime>0</calctime>
                     <nextupdate/>
                 </meta>
                 <sun rise="2020-10-05T02:31:49" set="2020-10-05T14:12:01"/>

                 <forecast>

                     <time from="2020-10-05T15:00:00" to="2020-10-05T18:00:00">
                         <symbol number="803" name="broken clouds" var="04n"/>
                         <precipitation probability="0.45"/>
                         <windDirection deg="37" code="NE" name="NorthEast"/>
                         <windSpeed mps="0.58" unit="m/s" name="Calm"/>
                         <temperature unit="celsius" value="17.2" min="17.2" max="18.46"/>
                         <feels_like value="15.9" unit="celsius"/>
                         <pressure unit="hPa" value="1021"/>
                         <humidity value="48" unit="%"/>
                         <clouds value="broken clouds" all="57" unit="%"/>
                         <visibility value="10000"/>
                     </time>

                     <time from="2020-10-05T18:00:00" to="2020-10-05T21:00:00">
                         <symbol number="500" name="light rain" var="10n"/>
                         <precipitation probability="0.36" unit="3h" value="0.2" type="rain"/>
                         <windDirection deg="45" code="NE" name="NorthEast"/>
                         <windSpeed mps="2" unit="m/s" name="Light breeze"/>
                         <temperature unit="celsius" value="17.29" min="17.29" max="17.64"/>
                         <feels_like value="14.75" unit="celsius"/>
                         <pressure unit="hPa" value="1020"/>
                         <humidity value="44" unit="%"/>
                         <clouds value="broken clouds" all="60" unit="%"/>
                         <visibility value="10000"/>
                     </time>

                     <time from="2020-10-05T21:00:00" to="2020-10-06T00:00:00">
                         <symbol number="803" name="broken clouds" var="04n"/>
                         <precipitation probability="0.08"/>
                         <windDirection deg="109" code="ESE" name="East-southeast"/>
                         <windSpeed mps="0.9" unit="m/s" name="Calm"/>
                         <temperature unit="celsius" value="16.72" min="16.72" max="16.77"/>
                         <feels_like value="14.72" unit="celsius"/>
                         <pressure unit="hPa" value="1020"/>
                         <humidity value="42" unit="%"/>
                         <clouds value="broken clouds" all="58" unit="%"/>
                         <visibility value="10000"/>
                     </time>

                 </forecast>
             </weatherdata>

        Dim ie As IEnumerable(Of XElement)
        'select all windSpeed nodes
        ie = From el In wd.<forecast>.<time>.<windSpeed>
             Select el

        For Each el As XElement In ie
            Debug.WriteLine(el.@name)
            ' Stop
        Next

        'a specific Block????
        Dim block As XElement = ie(1)
    End Sub

[ChrisE]

Hi guys I'm a beginner, i have a problem to read a attribute from a XML file, How can i read sub attribute from repeated attribute?


How Can Read (Name) Attribute from 2nd Block or 3rd Block?

well why not use the Attribute(s) then

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim x As XElement = XElement.Load("D:\TestWeather.xml")
        Dim getWinspeedData = x.Descendants("time")
        For Each xData In getWinspeedData
            Debug.WriteLine(xData.Elements("windSpeed").Attributes("name").ElementAt(0).Value)
            Debug.WriteLine(xData.Elements("windSpeed").Attributes("mps").ElementAt(0).Value)
            Debug.WriteLine(xData.Elements("windSpeed").Attributes("unit").ElementAt(0).Value)
            Debug.WriteLine("------------------------------------")
        Next xData
End Sub

[techgnome]

sorry I'm bigger and i don't understand your solution
For Example feels_like value repeated on 3 block, how can read feels_like value on block 2 or 3?


Attachment 178939

SelectSingleNode does just what it states... selects a single node... you don't want a single node... you want multiple nodes... use SelectNodes...

-tg