Add和AddRange的区别

Add和AddRange区别 Add和AddRange

Add：将指定的对象添加到……中

AddRange：向……末尾，添加数组

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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，而不要每次都加一次，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)

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

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原代码：

view plain
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.
11.    comm = New SqlCommand(strSql, Me.GetConn)
12.    comm.CommandType = ct
13.
14.    If param IsNot Nothing Then
15.        For i = 0 To param.Length - 1
16.            comm.Parameters.Add(param(i))
17.        Next i
18.    End If
19.
20.    Try
21.        dr = comm.ExecuteReader()
22.        dt.Load(dr)
23.    Catch ex As Exception
24.        Throw ex
25.    Finally
26.        dr.Close()
27.        conn.Close()
28.    End Try
29.
30.    Return dt
31.End Function  

修改后：

view plain
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.
10.    Comm = New SqlCommand(strSql, Me.GetConn)
11.    Comm.CommandType = myCommandType
12.
13.    If Param IsNot Nothing Then
14.        Comm.Parameters.AddRange(Param)
15.    End If
16.
17.    Try
18.        myDataReader = Comm.ExecuteReader
19.        dt.Load(myDataReader)
20.    Catch ex As Exception
21.        Throw ex
22.    Finally
23.        myDataReader.Close()
24.        Conn.Close()
25.    End Try
26.
27.    Return dt
28.End Function