小编Lau*_*oun的帖子

<Employees>
  <Employee>
    <EmpId>1</EmpId>
    <Name>Sam</Name>
    <Sex>Male</Sex>
    <Phone Type="Home">423-555-0124</Phone>
    <Phone Type="Work">424-555-0545</Phone>
  </Employee>
</Employees>

private void Window_Loaded(object sender, RoutedEventArgs e)
{
    emplyeeDetails = XDocument.Load(Directory.GetParent(Directory.GetCurrentDirectory()).Parent.FullName + "\\LinqToXml\\Xmls\\" + "Employees.xml");
    var emplyees = from emp in emplyeeDetails.Descendants("Employee").Take(10)
                   orderby emp.Element("EmpId").Value ascending
                   select new
                   {
                       Id = emp.Element("EmpId").Value,
                       Name = emp.Element("Name").Value,
                       Sex = emp.Element("Sex").Value,
                       WorkPhone=emp.Element("Phone").Attribute("Type").Value,
                       HomePhone = emp.Element("Phone").Attribute("Type").Value,                               
                   };
    DgrdEmployeeDetails.ItemsSource = emplyees.ToList();
}

使用上面的代码,我可以得到以下结果:

但我需要列WorkPhone的值424-555-0545而不是Home列HomePhone的值423-555-0124而不是列的值Home.

我该怎么办？

我有以下代码,它创建一个包含大量订单信息的XML文件.我希望能够更新此XML文件中的条目,而不是删除所有内容并重新添加所有内容.

我知道我可以这样做:

xElement.Attribute(attribute).Value = value;

但是这将改变与属性保持同名的每个属性.例如,当条目的Id等于"jason"时,我怎么才能改变某事物的价值？我是否需要加载XML文件,遍历整个文件,直到找到我想要更改的属性匹配,然后更改它,然后再次保存文件？

任何帮助/建议都非常感谢.

XElement xElement;
xElement = new XElement("Orders");

XElement element = new XElement(
    "Order",
    new XAttribute("Id", CustomId),
    new XAttribute("Quantity", Quantity),
    new XAttribute("PartNo", PartNo),
    new XAttribute("Description", Description),
    new XAttribute("Discount", Discount),
    new XAttribute("Freight", Freight),
    new XAttribute("UnitValue", UnitValue),
    new XAttribute("LineTotal", LineTotal)
    );
xElement.Add(element);
xElement.Save(PartNo + ".xml");

这是我的XML文件的样子:

<?xml version="1.0" encoding="utf-8"?>
<Orders>
    <Order Id="V45Y7B458B" Quantity="2" PartNo="5VNB98" Description="New Custom Item Description" Discount="2.00" Freight="2.90" UnitValue="27.88" LineTotal="25.09" />
    <Order Id="jason" Quantity="2" PartNo="jason" Description="New Custom Item Description" Discount="2.00" Freight="2.90" UnitValue="27.88" LineTotal="25.09" />
</Orders>

我正在尝试使用onChange另一个输入字段的功能更改复选框的值.

我有这样的事情:

class price extends React.Component {
    constructor(props) {
        super(props);

        this.state = {
            minValue: 0,
            maxValue: 20000,
            step: 1000,
            firstValue: null,
            secondValue: null,
            chcboxValue: false
        };

        this.handleChange = this.handleChange.bind(this);
    }

    componentWillMount() {
        this.setState({firstValue: this.state.minValue, secondValue: this.state.maxValue});
    }

    handleChange(name, event) {
        let value = event.target.value;
        // We set the state value depending on input that is clicked
        if(name === "second") {
            if(parseInt(this.state.firstValue) < parseInt(value)) {
                this.setState({secondValue:value});
            }
        } else {
            // The first value can't be greater than the …

我需要每5秒运行一次功能10分钟.

我使用计时器运行它5秒钟,但如何将计时器限制为仅10分钟？

我有这两个实体

public partial class Suscriptores
{
    public Suscriptores()
    {
       this.Publicacion = new HashSet<Publicacion>();
    }

    [Key]
    public int IdSuscriptor { get; set; }
    public string LogoSuscriptor { get; set; }
    public string Identificacion { get; set; }
    public string Nombre { get; set; }
    public string Direccion { get; set; }
    public string Telefono { get; set; }
    public string Email { get; set; }
    public string Fax { get; set; }
    public string Home { get; set; }

    public virtual …

我想从列表中获取不同的对象.我试图实施,IEqualityComparer但没有成功.请查看我的代码并给我一个解释IEqualityComparer.

public class Message
{
    public int x { get; set; }
    public string y { get; set; }
    public string z { get; set; }
    public string w { get; set; }
}

public class MessageComparer : IEqualityComparer<Message>
{
    public bool Equals(Message x, Message y)
    {
        if (Object.ReferenceEquals(x, y)) return true;

        if (Object.ReferenceEquals(x, null) || Object.ReferenceEquals(y, null))
            return false;

        if (x.x == y.x && x.y == y.y && x.z == y.z && x.w == y.w) …

我是React.js的新手,无法找到这个问题的任何答案.

我有一个评论博客,当我点击评论的标题时,标题应该改为另一个文本.我该怎么办？

我正在学习C#和Java,并且有关于继承的问题.

是否可以覆盖超类(基类)中的私有成员？在我看来,它不正确,因为访问修饰符会阻止访问该成员.

我想制作第一次点击开始rotorSpeed秒表然后第二次点击添加rotorSpeed.ElapsedMilliseconds到的代码list.在第二次点击重置秒表开始计时一次,然后在第三次点击再加rotorSpeed.ElapsedMilliseconds到list.代码中没有错误,但是当我调试它时,我收到错误double average = list.Average();

Stopwatch rotorSpeed = new Stopwatch(); List<double> list = new List<double>();

private void button1_Click(object sender, EventArgs e)
{
    i++;
    //Getting rotor speed
    if (i != 2)
    {               
        if (rotorSpeed.IsRunning)
        {
            rotorSpeed.Stop();
            list.Add(rotorSpeed.ElapsedMilliseconds);
            rotorSpeed.Start();                   
        }
        else
        {
            rotorSpeed.Reset();
            rotorSpeed.Start();
        }
    }

    double average = list.Average();
    textBox2.Text = average.ToString();
}

这是我得到的错误:

> System.Core.dll中发生了未处理的"System.InvalidOperationException"类型异常

附加信息:序列不包含任何元素

我正在学习使用Bootstrap并使用组件,特别是导航栏.我的链接/列表项没有显示,直接从Bootstrap复制.希望有人可以向我解释我缺少的东西.

<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
    <meta http-equiv="x-ua-compatible" content="ie=edge">
    <title>NavBar</title>

    <!-- bootstrap css -->
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.2/css/bootstrap.min.css" integrity="sha384-y3tfxAZXuh4HwSYylfB+J125MxIs6mR5FOHamPBG064zB+AFeWH94NdvaCBm8qnd" crossorigin="anonymous">
</head>    
<body>      
    <nav class="navbar navbar-toggleable-md navbar-light bg-faded">
        <button class="navbar-toggler navbar-toggler-right" type="button" data-toggle="collapse" data-target="#navbarNavAltMarkup" aria-controls="navbarNavAltMarkup" aria-expanded="false" aria-label="Toggle navigation">
            <span class="navbar-toggler-icon"></span>
        </button>
        <a class="navbar-brand" href="#">Navbar</a>
        <div class="collapse navbar-collapse" id="navbarNavAltMarkup">
            <div class="navbar-nav">
                <a class="nav-item nav-link active" href="#">Home <span class="sr-only">(current)</span></a>
                <a class="nav-item nav-link" href="#">Features</a>
                <a class="nav-item nav-link" href="#">Pricing</a>
                <a class="nav-item nav-link disabled" href="#">Disabled</a>
            </div>
        </div>
    </nav>      
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.4/jquery.min.js"></script>
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.2/js/bootstrap.min.js" integrity="sha384-vZ2WRJMwsjRMW/8U7i6PWi6AlO1L79snBrmgiDpgIWJ82z8eA5lenwvxbMV1PAh7" crossorigin="anonymous"> …