嗨我想製作一個通用/動態類的列表,使用XElement和DynamicLinq,然後顯示在dataGridView1.DataSource中C#如何使用動態Linq在運行時使用XElement創建一個自定義(動態)類
首先讓我們通過使用XElement類來製作xml。
// a List of String that are going to be our dynamic class's properties.
List<string> elements = new List<string>();
elements.Add("Name");
elements.Add("Address");
elements.Add("OtherElements1");
elements.Add("OtherElements2");
elements.Add("OtherElements3");
// XML Root Element
XElement XElement_Root = new XElement("Root");
// Item Element, This is our dynamic class
XElement XElement_Item = new XElement("Item");
// Insert the elements as XElements in the Item XElement
// This is like defining our Properties to our Item Class
foreach (String element in elements)
{
XElement_Item.Add(new XElement(element));
}
// Add 5 "Item" classes to the List "Root"
for (int cc = 0; cc < 5; cc++)
{
foreach (String elementName in elements)
{
// Adding a Random 10 length string to each "Item" Element(property)
XElement_Item.Element(elementName).Value = RandomString(10);
}
// Adding the populated "Class"(Item) to the "List<>"(Root)
XElement_Root.Add(new XElement(XElement_Item));
}
// Preview of the created xml.
String xml = XElement_Root.ToString();
它應該看起來像這樣。
- Root -
- Item -
- Name - KJHLRGOUDM - /Name -
- Address - QEOARCIIHO - /Address -
- OtherElements1 - LYHNXEPZCU - /OtherElements1 -
- OtherElements2 - MNSHTNYVXY - /OtherElements2 -
- OtherElements3 - DETZKZPJCE - /OtherElements3 -
- /Item -
- Item -
- Name - HYCNPMBTON - /Name -
- Address - QOSIADMHGE - /Address -
- OtherElements1 - ENLIKGEICX - /OtherElements1 -
- OtherElements2 - OGXYNOKFRH - /OtherElements2 -
- OtherElements3 - LEGJIPMKZH - /OtherElements3 -
- /Item -
...
- /Root -
這一切都很好。但現在我得到我的問題 我想把這個XML到一個類「項目」列表添加到我的dataGridView1.DataSource;
這可行,但它不是通用/動態的。
// Normal Linq !!! NOT GENERIC/DYNAMIC !!!
var listOfClassItem =
from classItem in XElement_Root.Descendants("Item") // "Item" is our class Name
select new
{
Name = classItem.Element("Name").Value,
Address = classItem.Element("Address").Value + " " +
classItem.Element("OtherElements1").Value,
PropertyZ = classItem.Element("OtherElements3").Value
};
// populate the dataGridView1.DataSource with the New List of Class Item
dataGridView1.DataSource = listOfClassItem.ToList();
The Grid然後看起來像這樣。對不起沒有圖像,工作塊everyting :(
=============================================================
| Name | Address | PropertyZ |
=============================================================
| SCTGCITLTN | NKMGDIYTGP LUCGNJCUNQ | DYJJJGPZDH |
| KBMZTYAMTS | FZXDYVFAJO KVIMMNKSWG | OLKTODAGLO |
| APQPXOSANG | NHQMYCIRWL QBHKZYKPXI | UERMLHVXVL |
| UIJZXZIFPY | DDCESJZHHT PHHERLJUZS | WHMKNQCMUB |
| INPBWNBEIM | QNGXVQKQRO NRXBXIUWRB | DQAYPIBOPX |
=============================================================
行,所以這是好的,但不是通用/動態, 我又試圖是這樣的。
// Dynamic Linq now this should be more GENERIC/DYNAMIC
// I want the User to be able to select which fields (properties) they want to show in the DataGrid
String selectQuery = GetSelectedFields(); // private String GetSelectedFields() { return ...}
// selectQuery will then be some thing like.
selectQuery = " new (Element(\"Name\").Value as Name, " +
" Element(\"Address\").Value + \" \" + Element(\"OtherElements1\").Value as Address, " +
" Element(\"OtherElements3\").Value as PropertyZ)";
// Then using Dynamic Linq to get the generic/dynamic class from the selection.
// !!! THIS IS WHERE I'M STUCK !!! this does not work. :(
var listOfClassItem2 = XElement_Root.Descendants("Item").AsQueryable().Select(selectQuery);
// I Found that this was the easiest way to get the "var" back to a List, to add to the .DataSource
// because the IQueryable above does not have a .ToList();
List<object> ListOfItem = new List<object>();
foreach (var varItem in listOfClassItem2)
{
ListOfItem.Add(varItem);
}
// populate the dataGridView1.DataSource with the New List of Class Dynamic Item
dataGridView1.DataSource = ListOfItem;
我收到以下錯誤消息。
No applicable method 'Element' exists in type 'XElement'
有人可以請幫我,
XElement_Root.Descendants("Item").AsQueryable().Select(selectQuery);
這樣我就可以得到和使用Normal Linq相同的結果。 Thx。