您的位置：首页 > 其它

在Silverlight中读取ADO.NET数据服务的两种方式

2010-03-10 11:32 417 查看

1。数据服务的返回数据格式

注意，没有办法通过添加引用的方式调用该服务，估计有安全方面的一些考虑吧

2。因为ADO.NET数据服务是可以直接通过http请求实现，所以下面两个代码都可以完成工作
首先准备地址和查询，并且直接通过webclient来发起请求即可

Uri svc = new Uri(Application.Current.Host.Source, "../NorthwindService.svc/Customers()?$orderby=CustomerID desc");

WebClient proxy = new WebClient();
proxy.OpenReadCompleted += new OpenReadCompletedEventHandler(proxy_OpenReadCompleted);
proxy.OpenReadAsync(svc);

然后在proxy_OpenReadCompleted方法中编写如下代码即可

XNamespace d = "http://schemas.microsoft.com/ado/2007/08/dataservices";
XNamespace xmlns = "http://www.w3.org/2005/Atom";
XDocument doc = XDocument.Load(e.Result);
var query = from entry in doc.Root.Elements(xmlns + "entry")
select new Customer()
{
CustomerID = entry.Descendants(d + "CustomerID").First().Value,
CompanyName = entry.Descendants(d + "CompanyName").First().Value,
Country = entry.Descendants(d + "Country").First().Value,
City = entry.Descendants(d + "City").First().Value
};

foreach (var item in query)
{
oc.Add(item);
}

.csharpcode, .csharpcode pre
{
font-size: small;
color: black;
font-family: consolas, "Courier New", courier, monospace;
background-color: #ffffff;
/*white-space: pre;*/
}
.csharpcode pre { margin: 0em; }
.csharpcode .rem { color: #008000; }
.csharpcode .kwrd { color: #0000ff; }
.csharpcode .str { color: #006080; }
.csharpcode .op { color: #0000c0; }
.csharpcode .preproc { color: #cc6633; }
.csharpcode .asp { background-color: #ffff00; }
.csharpcode .html { color: #800000; }
.csharpcode .attr { color: #ff0000; }
.csharpcode .alt
{
background-color: #f4f4f4;
width: 100%;
margin: 0em;
}
.csharpcode .lnum { color: #606060; }

.csharpcode, .csharpcode pre
{
font-size: small;
color: black;
font-family: consolas, "Courier New", courier, monospace;
background-color: #ffffff;
/*white-space: pre;*/
}
.csharpcode pre { margin: 0em; }
.csharpcode .rem { color: #008000; }
.csharpcode .kwrd { color: #0000ff; }
.csharpcode .str { color: #006080; }
.csharpcode .op { color: #0000c0; }
.csharpcode .preproc { color: #cc6633; }
.csharpcode .asp { background-color: #ffff00; }
.csharpcode .html { color: #800000; }
.csharpcode .attr { color: #ff0000; }
.csharpcode .alt
{
background-color: #f4f4f4;
width: 100%;
margin: 0em;
}
.csharpcode .lnum { color: #606060; }

另外，因为数据服务返回的数据其实是基于ATOM格式的，所以还可以通过下面的方式解析

XNamespace d = "http://schemas.microsoft.com/ado/2007/08/dataservices";
XNamespace xmlns = "http://www.w3.org/2005/Atom";
#region //读取到数据进行解析
XmlReader reader = XmlReader.Create(e.Result);
SyndicationFeed feed = SyndicationFeed.Load(reader);
foreach (var item in feed.Items)
{
XmlSyndicationContent c = (XmlSyndicationContent)item.Content;
XmlDictionaryReader r = c.GetReaderAtContent();
XElement element = XElement.Load(r);
oc.Add(new Customer()
{
CustomerID = element.Descendants(d + "CustomerID").First().Value,
CompanyName = element.Descendants(d + "CompanyName").First().Value,
Country = element.Descendants(d + "Country").First().Value,
City = element.Descendants(d + "City").First().Value
});

r.Close();

oc.Add(LoadXml(r));
}

reader.Close();

///
/// 这是一个静态方法，可以将一段XML转换为一个对象
///
///
///
///
public static T LoadXml(XmlReader reader)
where T:new()
{
XNamespace d = "http://schemas.microsoft.com/ado/2007/08/dataservices";
XElement element = XElement.Load(reader);
T result = new T();
foreach (var p in typeof(T).GetProperties())
{
Type pType = p.PropertyType;
string pName = p.Name;
string pValue = element.Descendants(d + pName).First().Value;
p.SetValue(result, Convert.ChangeType(pValue, pType, null), null);
}

reader.Close();
return result;

}

///
/// 这是一个静态方法，可以将一段XML转换为一个对象
///
///
///
///
public static T LoadXml(XElement element)
where T : new()
{
XNamespace d = "http://schemas.microsoft.com/ado/2007/08/dataservices";
T result = new T();
foreach (var p in typeof(T).GetProperties())
{
Type pType = p.PropertyType;
string pName = p.Name;
string pValue = element.Descendants(d + pName).First().Value;
p.SetValue(result, Convert.ChangeType(pValue, pType, null), null);
}

return result;

}

var query = from entry in doc.Root.Elements(xmlns + "entry")
select LoadXml(entry);

内容来自用户分享和网络整理，不保证内容的准确性，如有侵权内容，可联系管理员处理

标签：

相关文章推荐

新的分享

章节导航