Add和AddRange區別

Add和AddRange

 

Add：將指定的對象添加到……中

AddRange：向……末尾，添加數組

-

在群體操作時，使用AddRange取代Add 

用AddRange可以讓我們要加入的東西一次性加入，而不要每次都加一次，這樣顯然可以加快速度。幾乎所有的windows control都支持Add和AddRange兩種方法。

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的類： 
StringCollection, TraceCollection, SqlParameter, etc. 
HttpWebRequest 
UserControl 
ColumnHeader

修改前

''' ExecuteQuery,查詢數據操作  
''' </summary>  
''' <param name="strSql">sql語句</param>  
''' <param name="param">參數集合</param>  
''' <param name="ct">命令類型</param>  
''' <returns>DataTable類型，數據表</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

''' <summary>  
''' 查詢方法  
''' </summary>  
''' <param name="myCommandType">sql語句類型:區別於存儲過程</param>  
''' <param name="Param">參數數組</param>  
''' <param name="strSql">sql語句</param>  
Public Function ExecuteQuery(ByVal myCommandType As CommandType, ByVal Param() As SqlParameter, ByVal strSql As String) As DataTable  
    Dim dt As New DataTable  
  
    Comm = New SqlCommand(strSql, Me.GetConn)  
    Comm.CommandType = myCommandType  
  
    If Param IsNot Nothing Then  
        Comm.Parameters.AddRange(Param)  
    End If  
  
    Try  
        myDataReader = Comm.ExecuteReader  
        dt.Load(myDataReader)  
    Catch ex As Exception  
        Throw ex  
    Finally  
        myDataReader.Close()  
        Conn.Close()  
    End Try  
  
    Return dt  
End Function