[C#]Cosa devo studiare per... ?

[Mattyfog]

Allora, come al solito programmo in c#... Vorrei usare le api di yahoo music che detto in termini molto volgari si usano formulando richieste tramite un url.
Per esempio:
http://us.music.yahooapis.com/artist...ationidhere%5D
Il codice direi che è xml no? c'è sanke scritto
più che altro per usare queste api cosa devo studiare? avevo una rivista che mnne parlava ma l'ho persa.. devo imparare l xml?

[||ElChE||88]

http://en.wikipedia.org/wiki/Document_Object_Model
http://msdn.microsoft.com/en-us/library/system.xml.aspx

o

http://en.wikipedia.org/wiki/XPath
http://msdn.microsoft.com/en-us/libr...xml.xpath.aspx

[Mattyfog]

che cambia fra i due?

[Mattyfog]

up

[tomminno]

Originariamente inviato da Mattyfog

che cambia fra i due?

System.Xml contiene tutte le funzionalità base per lavorare con dati in formato XML
System.Xml.XPath fornisce funzionalità avanzate per la navigazione(e modifica) all'interno di dati in formato XML

Già che ci siamo io suggerirei anche System.Xml.Linq

[Mattyfog]

si ma damcosa parto? da System.Xml?

[Mattyfog]

adesso sto leggendo una guida su xml su html.it ma poi a che passo?

[theking0]

Ciao,
Vedi se ti può essere utile:

Link

[Mattyfog]

davvero grazie per quest'ultimo link.. mi studierò un po' di xml in generale e poi ci ritornerò per vederne l'applicazione

[Mattyfog]

mentre studio.. siccome mi viene un pochino complicato stare solo alla teoria.. mi potreste anche dire da cosa iniziare per la pratica?
System.Xml?
System.Xml.XPath?
System.Xml.Linq?
Per il momento devo solo leggere dei dati da un file xml come quello nell'esempio qua o se volete vederlo meglio alla pagina http://us.music.yahooapis.com/artist...ationidhere%5D:

<?xml version="1.0" encoding="utf-8" ?>
- <Artists start="1" count="3" total="3" errorCount="0">
- <Artist id="303902" name="Ligabue" rating="-1" flags="60847" catzillaID="1927208964" hotzillaID="1804454415" trackCount="213">
- <ItemInfo>
<Relevancy index="6658" />
</ItemInfo>
</Artist>
- <Artist id="157565157" name="Luciano Ligabue" rating="-1" flags="2" trackCount="0">
- <ItemInfo>
<Relevancy index="630" />
</ItemInfo>
</Artist>
- <Artist id="60858581" name="Ilva Ligabue" rating="-1" flags="2" trackCount="0">
- <ItemInfo>
<Relevancy index="629" />
</ItemInfo>
</Artist>
</Artists>
- <!-- wsapi-ext1.music.mud.yahoo.com compressed/chunked Tue Oct 27 14:30:34 PDT 2009
-->

[Mattyfog]

nessuno mi sa indicare i metodi migliori per leggere file xml in c#? ho visto che ci sono molte possibilità.. mi cerco io come funzionano però se mi sapeste dire quali sono migliori..

[^TiGeRShArK^]

se usi c# 4.0 probabilmente expando.
http://blogs.msdn.com/csharpfaq/arch...ndoobject.aspx

altrimenti direi System.xml.Linq se usi c# 3.x...

[Mattyfog]

uffa non so da dove partire..
ho un file così costruito (in alternativa ecco l'url http://us.music.yahooapis.com/track/...ationidhere%5D):

<?xml version="1.0" encoding="utf-8" ?> 
- <Tracks start="1" count="15" total="15" errorCount="1">
- <Track id="21777215" rating="-1" title="Certe Notti" explicit="0" flags="0" duration="0" releaseYear="2004" popularity="3" rights="0" discNumber="1" trackNumber="7" label="WM Italy">
  <Artist id="303902" name="Ligabue" rating="-1" /> 
- <Album>
- <Release id="21771273" rating="-1" title="Buon Compleanno Elvis" rights="3680">
  <Image size="135" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/023/909/23909539.jpg" /> 
  <Image size="40" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/023/909/23909540.jpg" /> 
  <Image size="80" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/023/909/23909541.jpg" /> 
  <Image size="110" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/023/909/23909542.jpg" /> 
  </Release>
  </Album>
- <ItemInfo>
  <Relevancy index="7167" /> 
  </ItemInfo>
  </Track>
- <Track id="30139761" rating="-1" title="Certe Notti" explicit="0" flags="0" duration="0" releaseYear="2004" popularity="3" rights="0" discNumber="2" trackNumber="10" label="Warner Bros.">
  <Artist id="303902" name="Ligabue" rating="-1" /> 
- <Album>
- <Release id="23687793" rating="-1" title="Su E Giù Da Un Palco" rights="3680">
  <Image size="135" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/033/544/33544589.jpg" /> 
  <Image size="40" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/033/544/33544590.jpg" /> 
  <Image size="80" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/033/544/33544591.jpg" /> 
  <Image size="110" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/033/544/33544592.jpg" /> 
  </Release>
  </Album>
- <ItemInfo>
  <Relevancy index="7150" /> 
  </ItemInfo>
  </Track>
- <Track id="185131425" rating="-1" title="Certe Notti" explicit="0" flags="0" duration="0" releaseYear="2004" popularity="3" rights="0" discNumber="2" trackNumber="24" label="Warner Bros.">
  <Artist id="303902" name="Ligabue" rating="-1" /> 
- <Album>
- <Release id="23687793" rating="-1" title="Su E Giù Da Un Palco" rights="3680">
  <Image size="135" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/033/544/33544589.jpg" /> 
  <Image size="40" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/033/544/33544590.jpg" /> 
  <Image size="80" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/033/544/33544591.jpg" /> 
  <Image size="110" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/033/544/33544592.jpg" /> 
  </Release>
  </Album>
- <ItemInfo>
  <Relevancy index="7145" /> 
  </ItemInfo>
  </Track>
- <Track id="46421241" rating="-1" title="Certe Notti" explicit="0" flags="0" duration="0" releaseYear="2006" popularity="3" rights="0" discNumber="1" trackNumber="11" label="Membran/Ombra">
  <Artist id="43422177" name="Membran Ltd. Presents" rating="-1" /> 
- <Album>
- <Release id="46420737" rating="-1" title="Io Ti Amo!: Le Piu Belle Canzoni Italiane D'Amore" rights="3952">
  <Image size="135" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/048/330/48330919.jpg" /> 
  <Image size="40" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/048/330/48330920.jpg" /> 
  <Image size="80" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/048/330/48330921.jpg" /> 
  <Image size="110" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/048/330/48330922.jpg" /> 
  </Release>
  </Album>
- <ItemInfo>
  <Relevancy index="7124" /> 
  </ItemInfo>
  </Track>
- <Track id="46421786" rating="-1" title="Certe Notti" explicit="0" flags="0" duration="0" releaseYear="2006" popularity="3" rights="0" discNumber="1" trackNumber="4" label="Membran/Ombra">
  <Artist id="43422177" name="Membran Ltd. Presents" rating="-1" /> 
- <Album>
- <Release id="46420806" rating="-1" title="A Tribute To Ligabue" rights="3952">
  <Image size="135" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/048/331/48331503.jpg" /> 
  <Image size="40" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/048/331/48331504.jpg" /> 
  <Image size="80" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/048/331/48331505.jpg" /> 
  <Image size="110" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/048/331/48331506.jpg" /> 
  </Release>
  </Album>
- <ItemInfo>
  <Relevancy index="7069" /> 
  </ItemInfo>
  </Track>
- <Track id="173433898" rating="-1" title="Certe Notti" explicit="0" flags="0" duration="0" releaseYear="1997" popularity="3" rights="0" discNumber="1" trackNumber="2">
  <Artist id="290217" name="Raoul Casadei" rating="-1" /> 
  <Album /> 
- <ItemInfo>
  <Relevancy index="7067" /> 
  </ItemInfo>
  </Track>
- <Track id="176896317" rating="-1" title="Certe Notti" explicit="0" flags="0" duration="0" releaseYear="1996" popularity="3" rights="0" discNumber="1" trackNumber="7" label="PolyGram">
  <Artist id="303902" name="Ligabue" rating="-1" /> 
- <Album>
  <Release id="159855326" rating="-1" title="For War Child" rights="0" /> 
  </Album>
- <ItemInfo>
  <Relevancy index="7066" /> 
  </ItemInfo>
  </Track>
  <Error code="404" id="28981068" description="null: com.yahoo.music.api.common.cache.BlockBlistNotFoundException" /> 
- <Track id="33444880" rating="-1" title="Certe Notti" explicit="0" flags="0" duration="264" releaseYear="2001" popularity="3" rights="0" discNumber="1" trackNumber="7" label="WEA International">
  <Artist id="303902" name="Ligabue" rating="-1" /> 
  <Album /> 
- <ItemInfo>
  <Relevancy index="7031" /> 
  </ItemInfo>
  </Track>
- <Track id="51809695" rating="-1" title="Certe Notti" explicit="0" flags="0" duration="0" releaseYear="2007" popularity="3" rights="0" discNumber="1" trackNumber="3" label="WM Italy">
  <Artist id="303902" name="Ligabue" rating="-1" /> 
- <Album>
- <Release id="51809120" rating="-1" title="Primo Tempo (Remastered)" rights="2048">
  <Image size="135" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/053/459/53459733.jpg" /> 
  <Image size="40" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/053/459/53459734.jpg" /> 
  <Image size="80" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/053/459/53459735.jpg" /> 
  <Image size="110" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/053/459/53459736.jpg" /> 
  </Release>
  </Album>
- <ItemInfo>
  <Relevancy index="7021" /> 
  </ItemInfo>
  </Track>
- <Track id="175881439" rating="-1" title="Certe Notti" explicit="0" flags="0" duration="0" releaseYear="2006" popularity="3" rights="0" discNumber="1" trackNumber="8" label="Replay">
  <Artist id="157519386" name="Gabry Group" rating="-1" /> 
- <Album>
  <Release id="159792494" rating="-1" title="Canzoni di Ligabue" rights="0" /> 
  </Album>
- <ItemInfo>
  <Relevancy index="7020" /> 
  </ItemInfo>
  </Track>
- <Track id="179898821" rating="-1" title="Certe Notti" explicit="0" flags="0" duration="0" releaseYear="2008" popularity="3" rights="0" discNumber="1" trackNumber="8">
  <Artist id="159736205" name="Gigi Sabani" rating="-1" /> 
- <Album>
  <Release id="160042838" rating="-1" title="Misto Fritto" rights="0" /> 
  </Album>
- <ItemInfo>
  <Relevancy index="7020" /> 
  </ItemInfo>
  </Track>
- <Track id="214761356" rating="-1" title="Certe Notti" explicit="0" flags="0" duration="0" releaseYear="2009" popularity="3" rights="0" discNumber="1" trackNumber="3">
  <Artist id="303902" name="Ligabue" rating="-1" /> 
  <Album /> 
- <ItemInfo>
  <Relevancy index="7019" /> 
  </ItemInfo>
  </Track>
- <Track id="173392444" rating="-1" title="Certe Notti - (with Ligabue)" explicit="0" flags="0" duration="0" releaseYear="1997" popularity="3" rights="0" discNumber="1" trackNumber="7">
  <Artist id="260414" name="Luciano Pavarotti" rating="-1" /> 
- <Album>
  <Release id="159588590" rating="-1" title="Modena For War Child '96" rights="0" /> 
  </Album>
- <ItemInfo>
  <Relevancy index="1176" /> 
  </ItemInfo>
  </Track>
- <Track id="187874943" rating="-1" title="Certe Notti [DVD]" explicit="0" flags="0" duration="0" releaseYear="2008" popularity="3" rights="0" discNumber="2" trackNumber="31" label="Warner">
  <Artist id="303902" name="Ligabue" rating="-1" /> 
  <Album /> 
- <ItemInfo>
  <Relevancy index="1075" /> 
  </ItemInfo>
  </Track>
  </Tracks>
- <!--  wsapi-ext1.music.mud.yahoo.com compressed/chunked Thu Oct 29 12:45:48 PDT 2009 
  -->

io devo individuare fra questi solo un artista.
Quindi dovrei capire come selezionare solo l'elemento Track id che ha come sottoelemento Artist id che ha l'attibuto name uguale a una mia variabile di tipo string.
Solo che non so come scrivere questo ne che metodi usare.. Non ci capisco più niente Ah, però sto provando a usare XElement che mi sembra molto comodo.

Grazie

[^TiGeRShArK^]

Ecco:

WebClient client = new WebClient();
client.DownloadFile("http://us.music.yahooapis.com/track/v1/list/search/track/certe_notti?appid=%5Byourapplicationidhere%5D", "file.xml");
XDocument doc = XDocument.Load("file.xml");
var tracks = from e in doc.Descendants("Track")
             where ((string)e.Element("Artist").Attribute("name")) == "Ligabue"
             select e;
                             
tracks.ToList().ForEach(Console.WriteLine);
Console.WriteLine();
tracks.Select(t => string.Format("Titolo: {0} - Autore: {1}", t.Attribute("title"),
    t.Element("Artist").Attribute("name"))).ToList().ForEach(Console.WriteLine);
Console.ReadLine();

Ed ecco il risultato:

<Track id="21777215" rating="-1" title="Certe Notti" explicit="0" flags="0" dura
tion="0" releaseYear="2004" popularity="3" rights="0" discNumber="1" trackNumber
="7" label="WM Italy">
  <Artist id="303902" name="Ligabue" rating="-1"></Artist>
  <Album>
    <Release id="21771273" rating="-1" title="Buon Compleanno Elvis" rights="368
0">
      <Image size="135" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000
/023/909/23909539.jpg" />
      <Image size="40" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/
023/909/23909540.jpg" />
      <Image size="80" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/
023/909/23909541.jpg" />
      <Image size="110" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000
/023/909/23909542.jpg" />
    </Release>
  </Album>
  <ItemInfo>
    <Relevancy index="7167" />
  </ItemInfo>
</Track>
<Track id="30139761" rating="-1" title="Certe Notti" explicit="0" flags="0" dura
tion="0" releaseYear="2004" popularity="3" rights="0" discNumber="2" trackNumber
="10" label="Warner Bros.">
  <Artist id="303902" name="Ligabue" rating="-1"></Artist>
  <Album>
    <Release id="23687793" rating="-1" title="Su E Giù Da Un Palco" rights="3680
">
      <Image size="135" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000
/033/544/33544589.jpg" />
      <Image size="40" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/
033/544/33544590.jpg" />
      <Image size="80" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/
033/544/33544591.jpg" />
      <Image size="110" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000
/033/544/33544592.jpg" />
    </Release>
  </Album>
  <ItemInfo>
    <Relevancy index="7150" />
  </ItemInfo>
</Track>
<Track id="185131425" rating="-1" title="Certe Notti" explicit="0" flags="0" dur
ation="0" releaseYear="2004" popularity="3" rights="0" discNumber="2" trackNumbe
r="24" label="Warner Bros.">
  <Artist id="303902" name="Ligabue" rating="-1"></Artist>
  <Album>
    <Release id="23687793" rating="-1" title="Su E Giù Da Un Palco" rights="3680
">
      <Image size="135" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000
/033/544/33544589.jpg" />
      <Image size="40" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/
033/544/33544590.jpg" />
      <Image size="80" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/
033/544/33544591.jpg" />
      <Image size="110" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000
/033/544/33544592.jpg" />
    </Release>
  </Album>
  <ItemInfo>
    <Relevancy index="7145" />
  </ItemInfo>
</Track>
<Track id="176896317" rating="-1" title="Certe Notti" explicit="0" flags="0" dur
ation="0" releaseYear="1996" popularity="3" rights="0" discNumber="1" trackNumbe
r="7" label="PolyGram">
  <Artist id="303902" name="Ligabue" rating="-1"></Artist>
  <Album>
    <Release id="159855326" rating="-1" title="For War Child" rights="0"></Relea
se>
  </Album>
  <ItemInfo>
    <Relevancy index="7066" />
  </ItemInfo>
</Track>
<Track id="33444880" rating="-1" title="Certe Notti" explicit="0" flags="0" dura
tion="264" releaseYear="2001" popularity="3" rights="0" discNumber="1" trackNumb
er="7" label="WEA International">
  <Artist id="303902" name="Ligabue" rating="-1"></Artist>
  <Album></Album>
  <ItemInfo>
    <Relevancy index="7031" />
  </ItemInfo>
</Track>
<Track id="51809695" rating="-1" title="Certe Notti" explicit="0" flags="0" dura
tion="0" releaseYear="2007" popularity="3" rights="0" discNumber="1" trackNumber
="3" label="WM Italy">
  <Artist id="303902" name="Ligabue" rating="-1"></Artist>
  <Album>
    <Release id="51809120" rating="-1" title="Primo Tempo (Remastered)" rights="
2048">
      <Image size="135" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000
/053/459/53459733.jpg" />
      <Image size="40" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/
053/459/53459734.jpg" />
      <Image size="80" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000/
053/459/53459735.jpg" />
      <Image size="110" url="http://us.ent1.yimg.com/images.launch.yahoo.com/000
/053/459/53459736.jpg" />
    </Release>
  </Album>
  <ItemInfo>
    <Relevancy index="7021" />
  </ItemInfo>
</Track>
<Track id="214761356" rating="-1" title="Certe Notti" explicit="0" flags="0" dur
ation="0" releaseYear="2009" popularity="3" rights="0" discNumber="1" trackNumbe
r="3">
  <Artist id="303902" name="Ligabue" rating="-1"></Artist>
  <Album></Album>
  <ItemInfo>
    <Relevancy index="7019" />
  </ItemInfo>
</Track>
<Track id="187874943" rating="-1" title="Certe Notti [DVD]" explicit="0" flags="
0" duration="0" releaseYear="2008" popularity="3" rights="0" discNumber="2" trac
kNumber="31" label="Warner">
  <Artist id="303902" name="Ligabue" rating="-1"></Artist>
  <Album></Album>
  <ItemInfo>
    <Relevancy index="1075" />
  </ItemInfo>
</Track>

Titolo: title="Certe Notti" - Autore: name="Ligabue"
Titolo: title="Certe Notti" - Autore: name="Ligabue"
Titolo: title="Certe Notti" - Autore: name="Ligabue"
Titolo: title="Certe Notti" - Autore: name="Ligabue"
Titolo: title="Certe Notti" - Autore: name="Ligabue"
Titolo: title="Certe Notti" - Autore: name="Ligabue"
Titolo: title="Certe Notti" - Autore: name="Ligabue"
Titolo: title="Certe Notti [DVD]" - Autore: name="Ligabue"

Da notare che è più lunga la parte per la stampa della parte per filtrare i risultati..

[Mattyfog]

grazie infinite!
non sapevo bene come scrivere questo:

var tracks = from e in doc.Descendants("Track")
             where ((string)e.Element("Artist").Attribute("name")) == "Ligabue"
             select e;

Toglimi ancora una curiosità... che differenza c'è tra XDocument e XElement?

[^TiGeRShArK^]

Originariamente inviato da Mattyfog

grazie infinite!
non sapevo bene come scrivere questo:

var tracks = from e in doc.Descendants("Track")
             where ((string)e.Element("Artist").Attribute("name")) == "Ligabue"
             select e;

Toglimi ancora una curiosità... che differenza c'è tra XDocument e XElement?

l'XDocument rappresenta l'intero documento xml, l'XElement è un elemento qualsiasi come Track o Artist.

[Mattyfog]

non capisco ancora come fare una cosa.. sempre in riferimento al documento xml di prima per ottenere il nome dell'album io faccio così:

tagmp3.Tag.Album = tracks.Descendants("Album").Select(t => t.Element("Release").Attribute("title")).ToString();

però ottengo qualcosa tipo system.xml.linq o qualcosa di simile invece che il nome dell'album..
cosa sbaglio?

[^TiGeRShArK^]

Originariamente inviato da Mattyfog

non capisco ancora come fare una cosa.. sempre in riferimento al documento xml di prima per ottenere il nome dell'album io faccio così:

tagmp3.Tag.Album = tracks.Descendants("Album").Select(t => t.Element("Release").Attribute("title")).ToString();

però ottengo qualcosa tipo system.xml.linq o qualcosa di simile invece che il nome dell'album..
cosa sbaglio?

se tracks è sempre la mia basterebbe fare così ad occhio:

tracks.Select(t => (string)t.Element("Album").Element("Release").Attribute("title"))).ToList().ForEach(Console.WriteLine);

[Mattyfog]

io scrivo così:
tagmp3.Tag.Album = tracks.Select(t => (string)t.Element("Album").Element("Release").Attribute("title")).ToString();
ma non va..
non sarà forse un problema del ToString() finale?

[^TiGeRShArK^]

Originariamente inviato da Mattyfog

io scrivo così:
tagmp3.Tag.Album = tracks.Select(t => (string)t.Element("Album").Element("Release").Attribute("title")).ToString();
ma non va..
non sarà forse un problema del ToString() finale?

direi che non ha molto senso in quel modo dato che stai facendo il toString su una collection di IEnumerable...