C# C XML文件显示登录用户的信息

我正在学习C语言，我正在解决一个问题。我创建了包含不同用户信息的XML文件。我有一个问题，显示一个特定的用户信息时，他的登录。我想显示使用用户名和密码的人的信息

因为现在即使第一个用户登录我也能看到第二个用户的信息

这是我用来显示信息的代码，但它不能正常工作

XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load("UserInfo.xml");
XmlNodeList nodeList = xmlDoc.DocumentElement.SelectNodes("/UsersInfo/UserInfo");

foreach (XmlNode node in nodeList)
{       
    FirstName.Text = node.SelectSingleNode("FirstName").InnerText;
    LastName.Text = node.SelectSingleNode("LastName").InnerText;
    DateOfBirth.Text = node.SelectSingleNode("DateOfBirth").InnerText;
    Nationality.Text = node.SelectSingleNode("Nationality").InnerText;
    Passport.Text=node.SelectSingleNode("Passport").InnerText;
    Address.Text = node.SelectSingleNode("Address").InnerText;
    Phone.Text = node.SelectSingleNode("phone").InnerText;

---

您可以将此作为示例。这就是我对天气的看法。这和你试图做的事情是一样的，只是使用了不同的方法。我展示的代码就是一个例子

 private void GetWeather()
    {
        string query = string.Format("http://weather.yahooapis.com/forecastrss?w=12773086");
        XmlDocument wData = new XmlDocument();
        wData.Load(query);

        XmlNamespaceManager manager = new XmlNamespaceManager(wData.NameTable);
        manager.AddNamespace("yweather", "http://xml.weather.yahoo.com/ns/rss/1.0");

        XmlNode channel = wData.SelectSingleNode("rss").SelectSingleNode("channel");
        XmlNodeList nodes = wData.SelectNodes("/rss/channel/item/yweather.forecast", manager);

        Temperature = channel.SelectSingleNode("item").SelectSingleNode("yweather:condition", manager).Attributes["temp"].Value;

        Condition = channel.SelectSingleNode("item").SelectSingleNode("yweather:condition", manager).Attributes["text"].Value;

        Humidity = channel.SelectSingleNode("yweather:atmosphere", manager).Attributes["humidity"].Value;

        Visibility = channel.SelectSingleNode("yweather:atmosphere", manager).Attributes["visibility"].Value;

        Pressure = channel.SelectSingleNode("yweather:atmosphere", manager).Attributes["pressure"].Value;

        Rising = channel.SelectSingleNode("yweather:atmosphere", manager).Attributes["rising"].Value;

        Town = channel.SelectSingleNode("yweather:location", manager).Attributes["city"].Value;

        State = channel.SelectSingleNode("yweather:location", manager).Attributes["region"].Value;

        Windspeed = channel.SelectSingleNode("yweather:wind", manager).Attributes["speed"].Value;

        Windchill = channel.SelectSingleNode("yweather:wind", manager).Attributes["chill"].Value;

        TFCond = channel.SelectSingleNode("item").SelectSingleNode("yweather:forecast", manager).Attributes["text"].Value;

        TFHigh = channel.SelectSingleNode("item").SelectSingleNode("yweather:forecast", manager).Attributes["high"].Value;

        TFLow = channel.SelectSingleNode("item").SelectSingleNode("yweather:forecast", manager).Attributes["low"].Value;

        Distance = channel.SelectSingleNode("yweather:units", manager).Attributes["distance"].Value;

        Sunrise = channel.SelectSingleNode("yweather:astronomy", manager).Attributes["sunrise"].Value;

        Sunset = channel.SelectSingleNode("yweather:astronomy", manager).Attributes["sunset"].Value;

        Speed = channel.SelectSingleNode("yweather:units", manager).Attributes["speed"].Value;

        BPressure = channel.SelectSingleNode("yweather:units", manager).Attributes["pressure"].Value;

        Degrees = channel.SelectSingleNode("yweather:units", manager).Attributes["temperature"].Value;

        Country = channel.SelectSingleNode("yweather:location", manager).Attributes["country"].Value;
    }

然后看看“温度”这个词。为了使用此功能，您需要添加

string Temperature;

然后您可以使用它，如下所示

 case "whats it like outside":
                      GetWeather();
                      Alexis.SpeakAsync("Currently it is, " + Condition + "with a high of " + Temperature + Degrees + ", there is a humidity of " + Humidity + "percent, and a windspeed of " + Windspeed + Speed);
                      break;

---

这是我每天使用的应用程序。因此，这应该给您一个想法。

从我所能看到的代码来看，您似乎是在集合中的每个用户之间循环，而不是选择一个特定的用户。可以使用linq形成查询，根据元素中包含的值选择特定元素，如下所示：

class Program
{
    static void Main(string[] args)
    {
        var xdoc =
            XDocument.Load(
                @"~\Examples\user.xml");

        var users = xdoc.Descendants("userInfo");

        // get the specific user
        var user = users.Where(x => x.Element("Passport").Value == "1");

        // get the value from each child element in the selected user 
        foreach(var element in user.Elements())
            {
            Console.WriteLine(element.Value);
        }

        Console.ReadLine();
    }
}

我假设passport字段是用于linq查询的唯一标识符，如您所见，这是一个非常简短的示例

我使用的xml：

<UsersInfo>
    <userInfo>
        <FirstName>First</FirstName>
        <LastName>Last</LastName>
        <Passport>1</Passport>
    </userInfo>
    <userInfo>
        <FirstName>Second</FirstName>
        <LastName>Last</LastName>
        <Passport>2</Passport>
    </userInfo>
</UsersInfo>

---

您需要匹配UserInfo节点中的用户名和密码。因此，只需在其中放置一个if构造，假设用户名和密码存储在XML中

XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load("UserInfo.xml");
XmlNodeList nodeList = xmlDoc.DocumentElement.SelectNodes("/UsersInfo/UserInfo");

foreach (XmlNode node in nodeList)
{
    if (node.SelectSingleNode("Username").InnerText == username &&
            node.SelectSingleNode("Password").InnertText == password)
    {
        FirstName.Text = node.SelectSingleNode("FirstName").InnerText;
        LastName.Text = node.SelectSingleNode("LastName").InnerText;
        DateOfBirth.Text = node.SelectSingleNode("DateOfBirth").InnerText;
        Nationality.Text = node.SelectSingleNode("Nationality").InnerText;
        Passport.Text=node.SelectSingleNode("Passport").InnerText;
        Address.Text = node.SelectSingleNode("Address").InnerText;
        Phone.Text = node.SelectSingleNode("phone").InnerText;
    }
}

然后，您将只匹配用户名和密码与输入的用户名/密码变量匹配的用户

---

你还应该考虑把密码散列，而不是把它存储在纯文本中，如果你还没有这样做。

玛丽，你提供的代码不足以定义什么不起作用。通过登录并在表单上显示当前用户来显示代码您可以显示您的XML模板吗？该文件中有多少用户信息？