嵌套foreach循環LINQ查詢

Question

我想下面的嵌套的foreach循環轉換到LINQ查詢

foreach (SAP.MOD mod in mods){ 
    foreach (SAP.RefMod r in refs){ 
     if (mod.RefModId == r.RefModId){ 
      modLookup.Add(mod.Modcode, r.ModItem); 
      break; 
     } 
    } 
} 

Answer 1

var query = from m in mods 
      join r in refs on m.RefModIf equals r.RefModId 
      select new { 
       mod.Modcode, 
       r.ModItem, 
      }; 

foreach (var i in query) 
    modLookup.Add(i.Modcode, i.ModItem); 

...如果modLookup是一本字典，你可以這樣做，而不是foreach ...

modLookup = query.ToDictionary(i=>i.Modcode, i=>i.ModItem); 

Answer 2

嘗試使用join：

var matches = mods.Join(refs, 
    m => wo.RefModId, 
    r => p.RefModId, 
    (mod,ref) => new {mod.RefModId, mod.Modcode, ref.ModItem} 
); 
matches.All(x => modLookup.Add(x.Modcode, x.ModItem));