百度Mp3的API在windows phone 7中的使用

namespace BaiduAPI_test
{
public partial class MainPage : PhoneApplicationPage
    {
// Constructor
        public MainPage()
        {
            InitializeComponent();
        }
public class MusicUpdateState
        {
public HttpWebRequest AsyncRequest { get; set; }
public HttpWebResponse AsyncResponse { get; set; }
        }
private void btn_search_Click(object sender, RoutedEventArgs e)
        {
//string gb_songname = utf_8_to_gb2312(SongName.Text);
//string gb_singername = utf_8_to_gb2312(SingerName.Text);

            //由於百度的地址是用GB2312編碼的，所以要用HttpUtility.UrlEncode這個函式來編碼
            string songname = HttpUtility.UrlEncode(SongName.Text);
string singername = HttpUtility.UrlEncode(SingerName.Text);

string Uri = "http://box.zhangmen.baidu.com/x?op=12&count=1&title=" + songname + "$$" + singername + "$$$$";

            UriBuilder fullUri = new UriBuilder(Uri);
            HttpWebRequest musicRequest = (HttpWebRequest)WebRequest.Create(fullUri.Uri);

            MusicUpdateState musicState = new MusicUpdateState();
            musicState.AsyncRequest = musicRequest;
            musicRequest.BeginGetResponse(new AsyncCallback(HandleMusicResponse), musicState);
        }

private void HandleMusicResponse(IAsyncResult asyncResult)
        {
            MusicUpdateState musicState = (MusicUpdateState)asyncResult.AsyncState;
            HttpWebRequest musicRequest = (HttpWebRequest)musicState.AsyncRequest;
            musicState.AsyncResponse = (HttpWebResponse)musicRequest.EndGetResponse(asyncResult);

            Stream streamResult;
string encode = "";
string decode = "";
            streamResult = musicState.AsyncResponse.GetResponseStream();
            //這裡也是一樣的，請求得到的XML是用GB2312編碼的，直接用XmlReader讀取Stream的話會提示系統不支援GB2312編碼
            var sr = new StreamReader(streamResult);
string srResult = sr.ReadToEnd();

//----Test----------

//Dispatcher.BeginInvoke(() =>
//    {
//        tb_decode.Text = srResult;
//    });

using (XmlReader reader = XmlReader.Create(new StringReader(srResult)))
            {
                reader.ReadToFollowing("encode");
                encode = reader.ReadElementContentAsString();

                //百度地址中間的數字是7位或者8位的，所以要判斷最後一個是不是數字
string encodeUrl = encode.Substring(44,8);
string lastNumberUri = IsNumber(encodeUrl);

                reader.ReadToFollowing("decode");
                decode = reader.ReadElementContentAsString();

                UriBuilder fullUri = new UriBuilder("http://zhangmenshiting.baidu.com/data/music/" + lastNumberUri + "/" + decode);
                Dispatcher.BeginInvoke(() =>
                    {
                        BaiduMusicElement.Source = fullUri.Uri;
                        BaiduMusicElement.AutoPlay = true;
                        BaiduMusicElement.Position = TimeSpan.FromMilliseconds(0);
                        BaiduMusicElement.Play();
                    });
            }
        }
private string IsNumber(string str)
        {//判斷str的最後一個字元是否數字
            int result;
string lastOne = str.Substring(7);
if (int.TryParse(lastOne, out result))
            {
return str;
            }
else
            {
return str.Substring(0, 7);
            }
        }

    }
}