幫我Linq查詢請

Question

我想獲得所有的資產，其中Class屬性等於selectedIClassesList中的一個值;

事情是這樣的：

from x in Assets where selectedIClassesList.Contains(x.Class) select x 

Answer 1

你可以做一個加入...

var query = from a in Assets 
      join s in selectedClassesList on a.Class equals s 
      select a; 

Answer 2

Assets.Where(x=>selectedIClassesList.Contains(x.Class)); 

Answer 3

如果我理解正確的，你的問題是，IClassesList沒有包含方法？如果IClassesList是與x.Class相同類型的對象的IEnumerable，這應該工作。

from x in Assets where selectedIClassesList.Any(s => s == x.Class) select x 

爲了獲得更好的性能，您儘可能創建一本字典。

var selectedClassesDict = selectedIClassesList.ToDictionary(s => s); 
var selectedAssets = from a in Assets 
        where selectedClassesDict.ContainsKey(a.Class) 
        select a;