在LINQ查询中避免双重控制搜索

dic
 .Select(kvp => new { Control = this.FindControl(kvp.Key), Visible = kvp.Value })
 .Where(i => i.Control != null)
 .ToList()
 .ForEach(p => { p.Control.Visible = p.Visible; });

dic.Select(p => new { Control = this.FindControl(p.Key), p.Value })
   .Where(p => p.Control != null)
   .ForEach(p => p.Control.Visible = p.Value);

…但我只是用 foreach 用一个 if 语句。不要过度使用LINQ。

看,没有匿名实例(不过,几乎没有更好的方法,更新组并枚举两次)

IEnumerable<IGrouping<bool, Control>> visibleGroups = 
  from kvp in controlVisibleDictionary
  let c = this.FindControl(kvp.Key)
  where c != null
  group c by kvp.Value;

foreach(IGrouping<bool, Control> g in visibleGroups)
{
  foreach(Control c in g)
  {
    c.Visible = g.Key;
  }
}

• 免责声明,不像foreach那么简单,如果

和大卫的想法一样,但是 一 字符串:

(from p in new System.Collections.Generic.Dictionary<string, bool>
{
    { "rowAddress", value },
    { "rowTaxpayerID", !value },
    { "rowRegistrationReasonCode", !value },
    { "rowAccountID", !value },
    { "rowAccountIDForeign", value },
    { "rowBankAddress", value },
    { "rowBankID", !value },
    { "rowBankSwift", value },
    { "rowBankAccountID", !value }
}
let c = this.FindControl(p.Key)
where c != null
select new // pseudo KeyValuePair
{
    Key = c,
    Value = p.Value
}).ForEach(p => p.Key.Visible = p.Value); // using own ext. method