protected override object returnResult(Hashtable results)
{
if (results == null)
return null; var entire = (new DataTable()).AsEnumerable();
foreach (DictionaryEntry entry in results)
{
if (entry.Value == null)
continue; DataTable tbl = (DataTable ) entry.Value ;
if (tbl.Rows.Count > 0) 这里Count==2
entire.Union<DataRow>(tbl.AsEnumerable()); 这句话执行到了
} if (entire.Count() > 0) 为什么这里Count=0?
return entire.CopyToDataTable<DataRow>();
else
return null;
}
{
if (results == null)
return null; var entire = (new DataTable()).AsEnumerable();
foreach (DictionaryEntry entry in results)
{
if (entry.Value == null)
continue; DataTable tbl = (DataTable ) entry.Value ;
if (tbl.Rows.Count > 0) 这里Count==2
entire.Union<DataRow>(tbl.AsEnumerable()); 这句话执行到了
} if (entire.Count() > 0) 为什么这里Count=0?
return entire.CopyToDataTable<DataRow>();
else
return null;
}
{
if (results == null)
return null; var entire = (new DataTable()).AsEnumerable();
foreach (DictionaryEntry entry in results)
{
if (entry.Value == null)
continue; DataTable tbl = (DataTable ) entry.Value ;
if (tbl.Rows.Count > 0) 这里Count==2
entire.Union<DataRow>(tbl.AsEnumerable()); 这句话执行到了
} if (entire.Count() > 0) 为什么这里Count=0?
return entire.CopyToDataTable<DataRow>();
else
return null;
}
using System; using System.Collections.Generic; public class UTest { public static void Main() { ICollection<int> unionResult = UnionHelper<int>.Union( new int[] { 1, 2, 3, 4, 5, 6, 7, 8, 9 }, new int[] { 1, 3, 5, 7, 9 }, new int[] { 1, 4, 7 } ); foreach (int i in unionResult) { Console.WriteLine(i); // 1,7 } } } class UnionHelper<T> { public static ICollection<T> Union(params ICollection<T>[] sets) { List<T> result = new List<T>(); if (sets.Length > 0) { ICollection<T> firstSet = sets.GetValue(0) as ICollection<T>; foreach (T element in firstSet) { bool isUnionElement = true; foreach (ICollection<T> set in sets) { if (!object.ReferenceEquals(set, firstSet) && !set.Contains(element)) { isUnionElement = false; break; } } if (isUnionElement) { result.Add(element); } } } return result; } }
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