我试图通过使用谷歌地图API执行一些操作来向另一个对象添加N个对象列表，但它只显示对象中的最后一个值。
if (Display.Dispaylist.Count > 0)
{
foreach (var d in Display.Dispaylist)
{
requestUri = string.Format("https://maps.googleapis.com/maps/api/place/details/xml?placeid=" + d.Placeid + "&radius=7500&sensor=true&key=AIzaSyA0SrtzNyotUjgqI8cwbfYNrRUkdCoACd8");
WebRequest request2 = WebRequest.Create(requestUri);
WebResponse response2 = request2.GetResponse();
XDocument xdoc2 = XDocument.Load(response2.GetResponseStream());
XElement generalElement1 = xdoc2.Element("PlaceSearchResponse");
Displayinfo.Dispaylisted = (from e in xdoc2.Descendants("result")
select new DisplacedModelList()
{
Name = Convert.ToString(e.Element("name").Value),
Address = (e.Element("formatted_address") != null ? Convert.ToString(e.Element("formatted_address").Value) : null),
Type = keyword,
PhoneNo = (e.Element("international_phone_number") != null ? Convert.ToString(e.Element("international_phone_number").Value) : null),
WebSite = (e.Element("website") != null ? Convert.ToString(e.Element("website").Value) : null),
Rating = (e.Element("rating") != null ? Convert.ToString(e.Element("rating").Value) : null)
}).ToList<DisplacedModelList>();
//Displayinfo.Dispaylisted.AddRange();
//.AddRange(Displayinfo);
//Displayinfo.Dispaylisted.AddRange(Displayinfo);
}
}
return View(Displayinfo);
因为每次我创建新对象所以在迭代结束时它会显示最后一个迭代值。 如何获取整个列表我是LINQ的新手.. 谢谢你的帮助。
答案 0 :(得分：0)
在将Display.Displaylisted属性设置为使用linq生成的新列表的代码行中。问题是您为foreach循环的每次迭代将其设置为新列表。您需要检查列表是否为null，如果它是新的，如果不是，则AddRange传入LINQ生成列表。我正在打电话，所以如果你需要一个例子我可以把我的笔记本电脑拿出去，输入代码就会很痛苦让我知道
----编辑---添加一些代码作为请求
下面我添加了一条评论，以显示您的代码出错的地方，并希望能够清除您正在做的事情
if (Display.Dispaylist.Count > 0)
{
foreach (var d in Display.Dispaylist)
{
requestUri = string.Format("https://maps.googleapis.com/maps/api/place/details/xml?placeid=" + d.Placeid + "&radius=7500&sensor=true&key=AIzaSyA0SrtzNyotUjgqI8cwbfYNrRUkdCoACd8");
WebRequest request2 = WebRequest.Create(requestUri);
WebResponse response2 = request2.GetResponse();
XDocument xdoc2 = XDocument.Load(response2.GetResponseStream());
XElement generalElement1 = xdoc2.Element("PlaceSearchResponse");
//----------------Here you are assigning a new list to the Property for every single iteration of the foreach loop, hence why you only see the last iteration value-----/
Displayinfo.Dispaylisted = (from e in xdoc2.Descendants("result")
select new DisplacedModelList()
{
Name = Convert.ToString(e.Element("name").Value),
Address = (e.Element("formatted_address") != null ? Convert.ToString(e.Element("formatted_address").Value) : null),
Type = keyword,
PhoneNo = (e.Element("international_phone_number") != null ? Convert.ToString(e.Element("international_phone_number").Value) : null),
WebSite = (e.Element("website") != null ? Convert.ToString(e.Element("website").Value) : null),
Rating = (e.Element("rating") != null ? Convert.ToString(e.Element("rating").Value) : null)
}).ToList<DisplacedModelList>();
}
}
return View(Displayinfo);
以下是我认为它应该做的事情
if (Display.Dispaylist.Count > 0)
{
//Initialise the list outside of the loop, just do it once
Displayinfo.Dispaylisted = new List<DisplacedModelList>();
foreach (var d in Display.Dispaylist)
{
requestUri = string.Format("https://maps.googleapis.com/maps/api/place/details/xml?placeid=" + d.Placeid + "&radius=7500&sensor=true&key=AIzaSyA0SrtzNyotUjgqI8cwbfYNrRUkdCoACd8");
WebRequest request2 = WebRequest.Create(requestUri);
WebResponse response2 = request2.GetResponse();
XDocument xdoc2 = XDocument.Load(response2.GetResponseStream());
XElement generalElement1 = xdoc2.Element("PlaceSearchResponse");
Displayinfo.Dispaylisted.AddRange(
(from e in xdoc2.Descendants("result")
select new DisplacedModelList()
{
Name = Convert.ToString(e.Element("name").Value),
Address = (e.Element("formatted_address") != null ? Convert.ToString(e.Element("formatted_address").Value) : null),
Type = keyword,
PhoneNo = (e.Element("international_phone_number") != null ? Convert.ToString(e.Element("international_phone_number").Value) : null),
WebSite = (e.Element("website") != null ? Convert.ToString(e.Element("website").Value) : null),
Rating = (e.Element("rating") != null ? Convert.ToString(e.Element("rating").Value) : null)
}).ToList<DisplacedModelList>()
);
}
}
return View(Displayinfo);
答案 1 :(得分：0)
使用原始代码，首先需要在IO::File之前初始化print $self ...：
public class Xbonacci
{
public double[] Tribonacci(double[] signature, int n)
{
double[] r = { 0 };
if (n==0)
{
return r;
}
List<double> t = new List<double>();
for (int i = 0; i < signature.Length; i++)
{
t.Add(signature[i]);
}
for (int i = 1; i < n-2; i++)
{
t.Add(t[i]+t[i+1]+t[i-1]);
}
return t.ToArray();
}
}
然后，在List内添加LINQ查询的所有返回值：
foreach如果您确实想使用LINQ来分配DisplayInfo.DisplayListed = new List<DisplacedModelList>();
，则需要在查询中包含foreach。您可以使用以下内容替换DisplayInfo.DisplayListed.AddRange((from e in xdoc2.Descendants("result")
select new DisplacedModelList() {
Name = Convert.ToString(e.Element("name").Value),
Address = (e.Element("formatted_address") != null ? Convert.ToString(e.Element("formatted_address").Value) : null),
Type = keyword,
PhoneNo = (e.Element("international_phone_number") != null ? Convert.ToString(e.Element("international_phone_number").Value) : null),
WebSite = (e.Element("website") != null ? Convert.ToString(e.Element("website").Value) : null),
Rating = (e.Element("rating") != null ? Convert.ToString(e.Element("rating").Value) : null)
}).ToList());
正文中的所有内容：
List