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：

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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