取得 Youtube 影片觀看次數。
參考資料:YouTube APIs and Tools – Reference Guide: Data API Protocol

/// <summary>  
/// 取得 Youtube 影片觀看次數  
/// </summary>  
/// <param name="youtubecode">Youtube 影片碼</param>  
/// <returns></returns>  
public static string GetYoutubeViewcount(string youtubecode)  
{  
string url = string.Format("http://gdata.youtube.com/feeds/api/videos/{0}?alt=json", youtubecode);  
System.Net.HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;

try  
{  
using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)  
{  
StreamReader reader = new StreamReader(response.GetResponseStream());  
string retVal = reader.ReadToEnd();

JObject googleSearch = JObject.Parse(retVal);  
return googleSearch\["entry"\]\["yt$statistics"\]\["viewCount"\].ToString();  
}  
}  
catch  
{  
return "0";  
}  
}

使用方法範例:

Response.Write(GetYoutubeViewcount("RCsCw9Vz7Nc"));

順便提一下取得縮圖的方式:
http://www.reelseo.com/youtube-thumbnail-image/

可用下面網址取得:
http://img.youtube.com/vi/VIDEO\_ID/#.jpg
# 可以為 0, 1, 2, 3

說明:

# 尺寸 第幾張縮圖
0 480×360 1
1 120×90 1
2 120×90 2
3 120×90 3