Question

我有一个加载条，每次设置它的值时都不会重新绘制。我试过多次最大化和最小化屏幕，但仍然显示0％的进度。代码尚未完成。任何的想法？代码：

import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JProgressBar;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class LoadingTest {
    public static void main(String[] args) throws ClassNotFoundException, InstantiationException, IllegalAccessException, UnsupportedLookAndFeelException {
        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
        F f = new F("Loading Bar Test");
    }
}
class F extends JFrame implements Runnable, ActionListener {
    private static final long serialVersionUID = 4684842549708528589L;
    private JProgressBar variableBar = new JProgressBar(0,100);
    private JProgressBar randomGenBar = new JProgressBar(0,100);
    private JProgressBar addBar = new JProgressBar(0,100);
    private JProgressBar totalbar = new JProgressBar(0,100);
    private JButton button;
    public F(String str) {
        setTitle(str);
        setDefaultCloseOperation(3);
        getContentPane().setLayout(new GridLayout(9,1));
        variableBar.setStringPainted(true);
        variableBar.setValue(0);
        button = new JButton("Run Tasks");
        button.addActionListener(this);
        add(button);
        add(new JLabel("Creating variables..."));
        add(variableBar);
        add(new JLabel("Generating Random Values..."));
        add(randomGenBar);
        add(new JLabel("Adding Values..."));
        add(addBar);
        add(new JLabel("Total Progress:"));
        add(totalbar);
        pack();
        setVisible(true);
    }
    public void run() {
        int p = 5;
        int i1;
        variableBar.setValue(p);
        int i2;
        p += 5;
        variableBar.setValue(p);
        int i3;
        p += 5;
        variableBar.setValue(p);
        int i4;
        p += 5;
        variableBar.setValue(p);
        int i5;
        p += 5;
        variableBar.setValue(p);
        int i6;
        p += 5;
        variableBar.setValue(p);
        int i7;
        p += 5;
        variableBar.setValue(p);
        int i8;
        p += 5;
        variableBar.setValue(p);
        int i9;
        p += 5;
        variableBar.setValue(p);
        int i10;
        p += 5;
        variableBar.setValue(p);
        int i11;
        p += 5;
        variableBar.setValue(p);
        int i12;
        p += 5;
        variableBar.setValue(p);
        int i13;
        p += 5;
        variableBar.setValue(p);
        int i14;
        p += 5;
        variableBar.setValue(p);
        int i15;
        p += 5;
        variableBar.setValue(p);
        int i16;
        p += 5;
        variableBar.setValue(p);
        int i17;
        p += 5;
        variableBar.setValue(p);
        int i18;
        p += 5;
        variableBar.setValue(p);
        int i19;
        p += 5;
        variableBar.setValue(p);
        int i20;
        p += 5;
        variableBar.setValue(p);
    }
    private F() {
    }
    public void actionPerformed(ActionEvent e) {
        new Thread(new F()).start();
    }
}

Answer 1

您正在actionPerformed方法中创建一个新的F对象。未示出的F对象中的JProgressBar正在进行中，但不在您正在显示的那个中。

尝试更改此内容：

new Thread(new F()).start();

到此：

new Thread(this).start();

看看会发生什么。

顺便说一下，你是从后台线程进行Swing调用，这是你绝对不应该做的事情。而是使用SwingWorker，设置其progress属性，然后使用PropertyChangeListener在Swing事件线程上侦听该属性。

除了编号2：您编写的后台主题将立即完成，因此您不会看到任何渐进的进展，而是立即完成进度。

Answer 2

当ActionEvent进入时，您将在新的run()上启动Thread方法，而不是事件调度线程，其中必须进行所有UI更新。< / p>

加载栏不重绘java

2 个答案: