Java

Question

所有编码运行s，我唯一的问题是进度条不显示值变化。我设置了值，但如果我运行它设置的值，则不会显示在进度条上。（栏未填满）

public void logIn() {
    try {
        while (true) {
            calculate();
            System.out.println(loadingProgress);
            if (loadingProgress < 100) {
                mGUI.pbLoading.setValue(loadingProgress);
                Thread.sleep(random.nextInt(5000) + 100);
            } else {
                mGUI.pbLoading.setValue(100);
                break;
            }
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

public void calculate() {
    random = new Random();
    loadingProgress = loadingProgress + random.nextInt(9) + 1;
}

Answer 1

计算必须在一个额外的线程中完成。这是因为当前运行线程正在阻塞 UI 的重绘，直到计算完成。

Answer 2

问题出在您发布的代码之外。我用你的代码创建了一个工作示例：

package snippet;

import java.util.Random;

public class Snippet {
    public class ValueAccepter {

        public void setValue(int loadingProgress) {
            System.out.println(loadingProgress);
        }

    }

    public class MGUI {

        public final ValueAccepter pbLoading = new ValueAccepter();

    }

    private int loadingProgress;
    private Random random;
    private MGUI mGUI = new MGUI();

    public static void main(String[] args) {
        new Snippet().logIn();
    }

    public void logIn() {
        try {
            while (true) {
                calculate();
                System.out.println(loadingProgress);
                if (loadingProgress < 100) {
                    mGUI.pbLoading.setValue(loadingProgress);
                    Thread.sleep(random.nextInt(5000) + 100);
                } else {
                    mGUI.pbLoading.setValue(100);
                    break;
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void calculate() {
        random = new Random();
        loadingProgress = loadingProgress + random.nextInt(9) + 1;
    }
}

我认为你的 swing-threads 有问题。确保 mGUI.pbLoading.setValue 按预期返回。

Answer 3

你必须使用 SwingWorker to execute graphical user interface operations and calculations otherwise the event dispatch thread won't be able to repaint. Here 是 Oracle 的进度条演示代码。

Java - 进度条没有进展

Java - Progress Bar Not Progressing

swing

jprogressbar