AddRange 取代 Add

cmd.Parameters的Add方法是增加一个参数,增加多个参数的的时候使用一个foreach循环，cmd.Parameters的AddRange方法是增加一个参数的数组。

Add：将指定的对象添加到……中

AddRange：向……末尾，添加数组

在群体操作时，使用AddRange取代Add

用AddRange可以让我们要加入的东西一次性加入，而不要每次只加一个，这样显然可以加快速度。几乎所有的windows control都支持Add和AddRange两种方法。

Add:

For i = 0 To param.Length - 1
comm.Parameters.Add(param(i))
Next i

AddRange:

Comm.Parameters.AddRange(Param)

支持Add和AddRange的类：
StringCollection, TraceCollection, SqlParameter, etc.
HttpWebRequest
UserControl
ColumnHeader

原代码：

1. ''' ExecuteQuery,查询数据操作
2. ''' </summary>
3. ''' <param name="strSql">sql语句</param>
4. ''' <param name="param">参数集合</param>
5. ''' <param name="ct">命令类型</param>
6. ''' <returns>DataTable类型，数据表</returns>
7. ''' <remarks></remarks>
8. Public Function ExecuteQuery(ByVal strSql As String, ByVal param() As SqlParameter, ByVal ct As CommandType) As DataTable
9. Dim dt As New DataTable
10. comm = New SqlCommand(strSql, Me.GetConn)
11. comm.CommandType = ct
12. If param IsNot Nothing Then
13. For i = 0 To param.Length - 1
14. comm.Parameters.Add(param(i))
15. Next i
16. End If
17. Try
18. dr = comm.ExecuteReader()
19. dt.Load(dr)
20. Catch ex As Exception
21. Throw ex
22. Finally
23. dr.Close()
24. conn.Close()
25. End Try
26. Return dt
27. End Function

''' ExecuteQuery,查询数据操作
''' </summary>
''' <param name="strSql">sql语句</param>
''' <param name="param">参数集合</param>
''' <param name="ct">命令类型</param>
''' <returns>DataTable类型，数据表</returns>
''' <remarks></remarks>
Public Function ExecuteQuery(ByVal strSql As String, ByVal param() As SqlParameter, ByVal ct As CommandType) As DataTable
Dim dt As New DataTable

comm = New SqlCommand(strSql, Me.GetConn)
comm.CommandType = ct

If param IsNot Nothing Then
For i = 0 To param.Length - 1
comm.Parameters.Add(param(i))
Next i
End If

Try
dr = comm.ExecuteReader()
dt.Load(dr)
Catch ex As Exception
Throw ex
Finally
dr.Close()
conn.Close()
End Try

Return dt
End Function

修改后：

1. ''' <summary>
2. ''' 查询方法
3. ''' </summary>
4. ''' <param name="myCommandType">sql语句类型:区别于存储过程</param>
5. ''' <param name="Param">参数数组</param>
6. ''' <param name="strSql">sql语句</param>
7. Public Function ExecuteQuery(ByVal myCommandType As CommandType, ByVal Param() As SqlParameter, ByVal strSql As String) As DataTable
8. Dim dt As New DataTable
9. Comm = New SqlCommand(strSql, Me.GetConn)
10. Comm.CommandType = myCommandType
11. If Param IsNot Nothing Then
12. Comm.Parameters.AddRange(Param)
13. End If
14. Try
15. myDataReader = Comm.ExecuteReader
16. dt.Load(myDataReader)
17. Catch ex As Exception
18. Throw ex
19. Finally
20. myDataReader.Close()
21. Conn.Close()
22. End Try
23. Return dt
24. End Function