将两个DataTable合并成一个Datatable

 //两个结构一样的DT合并
DataTable DataTable1 = new DataTable();
DataTable DataTable2 = new DataTable();
DataTable newDataTable = DataTable1.Clone();

object[] obj = new object[newDataTable.Columns.Count];
for (int i = 0; i < DataTable1.Rows.Count; i++)
{
    DataTable1.Rows[i].ItemArray.CopyTo(obj,0);
    newDataTable.Rows.Add(obj);
}

for (int i = 0; i < DataTable2.Rows.Count; i++)
{
    DataTable2.Rows[i].ItemArray.CopyTo(obj,0);
    newDataTable.Rows.Add(obj);
}
//两个结构不同的DT合并
///

  /// 将两个列不同的DataTable合并成一个新的DataTable
  ///

  /// 表1
  /// 表2
  /// 合并后新的表名
  ///
  private DataTable UniteDataTable( DataTable dt1 ,DataTable dt2 ,string DTName)
  { 
   DataTable dt3 = dt1.Clone();
   for( int i = 0 ;i < dt2.Columns.Count ;i ++ )
   {
    dt3.Columns.Add( dt2.Columns[i].ColumnName ) ;
   }
   object[] obj = new object[dt3.Columns.Count];
   
   for (int i = 0; i < dt1.Rows.Count; i++)
   {
    dt1.Rows[i].ItemArray.CopyTo(obj,0);
    dt3.Rows.Add(obj);
   }
      
   if( dt1.Rows.Count >= dt2.Rows.Count )
   {
    for( int i = 0 ;i < dt2.Rows.Count ;i++ )
    {
     for( int j = 0 ;j < dt2.Columns.Count ;j ++ )
     {
      dt3.Rows[i][j+dt1.Columns.Count] = dt2.Rows[i][j].ToString() ;
     }
    }
   }
   else
   {
    DataRow dr3 ;
    for( int i = 0 ;i < dt2.Rows.Count - dt1.Rows.Count ;i ++ )
    {
     dr3 = dt3.NewRow() ;
     dt3.Rows.Add( dr3 ) ;
    }
    for( int i = 0 ;i < dt2.Rows.Count ;i++ )
    {
     for( int j = 0 ;j < dt2.Columns.Count ;j ++ )
     {
      dt3.Rows[i][j+dt1.Columns.Count] = dt2.Rows[i][j].ToString() ;
     }
    }
   }
   dt3.TableName = DTName ; //设置DT的名字
   return dt3 ;
  }

  //多个 结构相同的DataTable合并

  public DataTable GetAllEntrysDataTable()
  {
      DataTable newDataTable = GetEntrysDataTable(0).Clone();

      object[] obj = new object[newDataTable.Columns.Count];

      for (int i = 0; i < entryGroups.GetEntryGroupCount(); i++)
      {
          for (int j = 0; j < GetEntrysDataTable(i).Rows.Count; j++)
          {
              GetEntrysDataTable(i).Rows[j].ItemArray.CopyTo(obj, 0);
              newDataTable.Rows.Add(obj);
          }
      }
      return newDataTable;
  }