Question

我正在构建一个非常小的Java Applet示例。通常，我使用C＃而不是Java编程。不要责怪我没有使用布局管理器，我知道事情可能更有效率。我的问题是我无法在标签或文本字段上显示保存在名为“weerAttribuutValueLabelList”的ArrayList中的XML值。当我检查ArrayList时，所有从XML文件接收的值都存在。

它必须是一个小小的愚蠢的东西，它与C＃或我认为的类似。我希望有人可以帮助我，我已经做了很多努力找到原因，但现在我已经没有想法了。非常感谢你。

代码块：

import java.awt.*; 
import java.applet.*; 
import java.awt.event.*; 
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import org.w3c.dom.Document;
import org.w3c.dom.NodeList;
import org.w3c.dom.Node;
import org.w3c.dom.Element;
import java.net.*;
import java.io.*;
import java.util.ArrayList;

public class ReadXml extends Applet implements ActionListener 
{
    NodeList xmlValueList;
    ArrayList<Label> weerAttribuutLabelList;
    ArrayList<Label> weerAttribuutValueLabelList;

    int weerAttribuutLabelMargin = 20;
    int weerAttribuutValueLabelMargin = 20;

public void init()
{
    // Location for every generated label
    weerAttribuutLabelList = new ArrayList <Label>();
    weerAttribuutValueLabelList = new ArrayList <Label>();

    // Generate the static labels with defined text label at first
    staticLabel();

    // Download the xml, put the xml values in a label and save them in the ArrayList
    readXmlFile();

    labelAligning();    
}

// Every static label gets a defined text label from the array
public void staticLabel()
{
    String[] regentHetInXmlNames = {"Datum:", "Tijd:", "Temperatuur (°C):", "Trend (/uur):", "Max. temperatuur:", "Min. temperatuur:", "Gevoelstemperatuur:", "Min. gevoelstemp.:", "Dauwpunt:", "Trend (/uur):", "Max. dauwpunt:", "Min. dauwpunt:", "Luchtvochtigheid:", "Trend (/uur):", "Max. luchtvochtigheid:", "Min. luchtvochtigheid:", "Neerslag:", "Luchtdruk:", "Trend (/uur):", "Max. luchtdruk:", "Min. luchtdruk", "Windsnelheid:", "Windsnelheid (10 min):", "Max. windstoot:", "Windrichting:", "UV:", "Max. UV:"};

    for(String name : regentHetInXmlNames)
    {
        weerAttribuutLabelList.add(new Label(name));
    }
}

// Read xml
public void readXmlFile()
{
    try 
    {
        DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
        Document regenthetinXml = dBuilder.parse(new URL("http://regenthet.in/data/regenthetin.xml").openStream());

        regenthetinXml.getDocumentElement().normalize();

        String[] regentHetInXmlNodes = {"stationDate", "stationTime", "outsideTemp", "tempChangeLastHour", "hiOutsideTemp", "lowOutsideTemp", "windchill", "lowWindchill", "outsideDewPt", "dewChangeLastHour", "hiDewpoint", "lowDewpoint", "outsideHumidity", "humChangeLastHour", "hiHumidity", "lowHumidity", "dailyRain", "pressure", "pressChangeLastHour", "hiPressure", "lowPressure", "windSpeed", "wind10Avg", "hiWindSpeed", "windDirection", "uv", "hiUV"};

        xmlValueList = regenthetinXml.getElementsByTagName("station_almelo");
        Node nNode = xmlValueList.item(0);

        Element eElement = (Element) nNode;
        for(int i = 0; i <= 26; i++)
        {
            weerAttribuutValueLabelList.add(new Label(eElement.getElementsByTagName(regentHetInXmlNodes[i]).item(0).getTextContent()));
            //System.out.println(eElement.getElementsByTagName(regentHetInXmlNodes[i]).item(0).getTextContent());
        }         
    }

    catch(Exception e)
    {}
}

public void labelAligning()
{
    // Visual default aspects
    setLayout(null);
    setBackground(Color.lightGray);

    for(Label item : weerAttribuutLabelList)
    {
        item.setBounds(20,weerAttribuutLabelMargin,150,20);
        add(item);
        weerAttribuutLabelMargin = weerAttribuutLabelMargin + 20;
        //System.out.println(item);
    }

    for(Label item : weerAttribuutValueLabelList)
    {
        item.setBounds(250,weerAttribuutValueLabelMargin,150,20);
        add(item);
        weerAttribuutValueLabelMargin = weerAttribuutValueLabelMargin + 20;
        System.out.println(item);
    }
}

public void actionPerformed(ActionEvent event)
{          
}
}

Image, for clarifying

Answer 1

您想要的布局需要两列，所以至少可以使用GridLayout（26,2）或类似的并添加标签。看看会发生什么，然后你可以在学习时使用其他布局。

Java applet：无法在标签或其他gui元素上显示xml值

1 个答案: