我正在Windows上运行ruby 1.9.2并试图移植在Ruby 1.8中运行的代码.该代码使用Open4.popen4,以前工作正常.在1.9.2中,我做了以下工作:
gem install POpen4require 'popen4'Open4.popen4("cmd") {|io_in,io_out,io_er| ... }当我这样做时,我收到错误:
no such file to load -- win32/open3
如果我尝试安装win32-open3(gem install win32-open3),我会收到错误消息:
win32-open3 requires Ruby version < 1.9.0
有谁知道我是如何解决这个问题的？
我可以像在SQL预处理语句中一样拥有String java的占位符吗？
例如,我有 string St = "akkk ? la,ala ? " ,
现在我想设定值？因为我在sql准备语句st.setStingValue(1,"akshay")中设置它; //我们有这样的事吗？St.setStringValue(2, "anjaaa");
Feb 8, 2011 11:56:49 AM com.sun.xml.internal.messaging.saaj.client.p2p.HttpSOAPC
onnection post
SEVERE: SAAJ0009: Message send failed
com.sun.xml.internal.messaging.saaj.SOAPExceptionImpl: java.security.PrivilegedA
ctionException: com.sun.xml.internal.messaging.saaj.SOAPExceptionImpl: Message s
end failed
at com.sun.xml.internal.messaging.saaj.client.p2p.HttpSOAPConnection.cal
l(Unknown Source)
at external.main(external.java:47)
Caused by: java.security.PrivilegedActionException: com.sun.xml.internal.messagi
ng.saaj.SOAPExceptionImpl: Message send failed
at java.security.AccessController.doPrivileged(Native Method)
... 2 more
Caused by: com.sun.xml.internal.messaging.saaj.SOAPExceptionImpl: Message send f
ailed
at com.sun.xml.internal.messaging.saaj.client.p2p.HttpSOAPConnection.pos
t(Unknown Source)
at com.sun.xml.internal.messaging.saaj.client.p2p.HttpSOAPConnection$Pri
viledgedPost.run(Unknown Source)
... 3 more
Caused by: java.net.ConnectException: Connection timed out: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(Unknown Source)
at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown …我们知道如果n不是一个完美的正方形,那么sqrt(n)就不会是一个整数.由于我只需要整数部分,我觉得调用sqrt(n)不会那么快,因为计算小数部分也需要时间.
所以我的问题是,
我们是否只能获得sqrt(n)的整数部分而不计算实际值sqrt(n)？算法应该比sqrt(n)(在<math.h>或中定义<cmath>)更快？
如果可能,您也可以在asm块中编写代码.
考虑以下:
class A{
//data members
void foo()
{
bar();//is this possible? or should you say this->bar() note that bar is not static
}
void bar()
{
}
}//end of class A
你如何从另一个内部调用成员函数？静态函数如何影响'this'的使用.应该在对象上调用函数吗？
我有一个模特
public class Person {
public string Name { get; set; }
public int Age { get; set; }
}
和一个简单的视图
<%@ Page Language="C#" Inherits="System.Web.Mvc.ViewPage<IList<Site.Models.Person>>" %>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
</head>
<body>
<% for (int i = 0 ; i < Model.Count ; i++) { %>
<%: Html.DisplayFor(m => m[i])%>
<% } %>
</body>
</html>
部分视图
<%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<Site.Models.Person>" %>
<h1>A person</h1>
<div>Name: <%: Html.DisplayFor(x => x.Name)%></div>
<div>Age: <%: Html.DisplayFor(x => x.Age)%></div>
和单个控制器
public ActionResult Index () {
Person …我有一个整数列,我需要搜索所述列以19开头的行
在MySQL中我会使用SELECT ... WHERE idLIKE '19%'
ERROR: operator does not exist: integer ~~ unknown LINE 1: select * from "table" where "id" like '19%'
我应该何时使用Sql Azure,何时应该使用表存储？我在想,将表存储用于事务处理方案,例如借记贷方帐户类型的方案,并在数据不用于交易目的时使用Sql Azure,例如报告.你怎么看？
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Literal1.Text = Request.QueryString("Pno")
On Error Resume Next
Dim SQLData As New System.Data.SqlClient.SqlConnection("workstation id=ws.example.com;packet size=4096;user id=some-user;pwd=some-password;data source=mssql.example.com;persist security info=False;initial catalog=some-db")
Dim cmdSelect As New System.Data.SqlClient.SqlCommand("SELECT * FROM a1_ticket WHERE PNR_no ='" & Literal1.Text & "'", SQLData)
SQLData.Open()
Dim dtrReader As System.Data.SqlClient.SqlDataReader = cmdSelect.ExecuteReader()
If dtrReader.HasRows Then
While dtrReader.Read()
Literal2.Text = dtrReader("bus_type")
Literal3.Text = dtrReader("dep_time")
Literal4.Text = dtrReader("PRN")
Literal5.Text = dtrReader("fro_m")
Literal6.Text = dtrReader("seat_opt")
Literal7.Text = dtrReader("Ticket_no")
Literal8.Text = dtrReader("t_o") …