Question

这是我正在构建https://github.com/chrisbramm/LastFM-History-Graph的应用程序。

以下是src/lastfmhistoryclasses中控制器类的一部分。创建OutputGUIView后，它会创建三个组件JPanel graphPanel，这会添加到JScrollPane graphScrollPanel和另一个JPanel autocompletePanel。然后将这些全部添加到JFrame OutputGUIView。然后，下面的监听器会更改graphPanel的首选大小，并且当您第一次按下按钮时，UI会更新，以显示graphPanel的大小已增加且graphScrollPanel的滚动条已更改。< / p>

但是现在，如果按另一个按钮，首选大小会更改，但UI不会更新，如果您更改窗口尺寸，则会执行此操作，让我们说最大化它。

class Zoom2000 implements ActionListener{
    public void actionPerformed(ActionEvent e){
        outputGUIView.graphPanel.setPreferredSize(new Dimension(screenWidth, 2000));
        outputGUIView.graphScrollPanel.updateUI();

    }
}
class ZoomDefault implements ActionListener{
    public void actionPerformed(ActionEvent e){
        outputGUIView.graphPanel.setPreferredSize(new Dimension(screenWidth, screenHeight));
        outputGUIView.graphScrollPanel.updateUI();


    }
}
class Zoom6000 implements ActionListener{
    public void actionPerformed(ActionEvent e){
        outputGUIView.graphPanel.setPreferredSize(new  Dimension(screenWidth, 6000));
        outputGUIView.graphScrollPanel.updateUI();

    }
}

我已经尝试了不同的东西，例如invalidate/validate/revalidate（并重新绘制）各种组件，而graphPanel只是坐在那里，只有在你改变窗口尺寸时才重新绘制。

任何想法我做错了什么？

编辑更新：这是GraphPanel类：

package lastfmhistoryguis;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.Line2D;
import java.awt.geom.Rectangle2D;
import javax.swing.*;

import de.umass.lastfm.*;
import lastfmhistoryclasses.*;

SuppressWarnings("serial")
public class GraphPanel extends JPanel {

private LastFMHistory graphData;
private int graphHeight;
private int graphWidth;
private int zoom;
private final int PAD = 20;

public GraphPanel(LastFMHistory model, int zoom){
    this.graphData = model;
    if (zoom != 1){
        this.zoom = zoom;
    }else{
        this.zoom = 1;
        System.out.println("getHeight() returning:" + getHeight());
    }
    System.out.println("Width" + getWidth() + "Height" + getHeight());

}

protected void paintComponent(Graphics g) {
    super.paintComponent(g);
     System.out.println("Drawing");
    Graphics2D graph = (Graphics2D) g;

    if (graphData == null) {
        System.err.println("No data found");
    } else {
        System.out.println("paintComponent Width" + getWidth() + "Height" + getHeight());
        graphWidth = getWidth() - 5 * PAD;
        //graphHeight = getHeight() - 2 * PAD;
        graphHeight = 6000 - 2* PAD;
        System.out.println(graphWidth + ", " + graphHeight);

        int x0 = graphWidth + PAD;
        graph.draw(new Rectangle2D.Double(PAD, PAD, graphWidth, graphHeight));
        double xInc = (double) (graphWidth) / (graphData.dayMax);
        double secondHeight = (double) (graphHeight) / 86400;

        for (int i = 0; i <= 86400; i++) {
            if (i % 3600 == 0) {
                graph.draw(new Line2D.Double(x0, (i * secondHeight) + PAD,
                        x0 + 10, (i * secondHeight) + PAD));
                String hour = Integer.toString(i / 3600);
                graph.drawString(hour, x0 + 15,
                        (int) ((i * secondHeight) + PAD));
            }
        }

        for (Track t : graphData.history) {
            if (t.getPlayedWhen() != null) {

                Color color = t.getColour();

                int duration = t.getDuration();
                int day = Math.abs(t.getDay());
                double dayOrigin = x0 - ((day + 1) * xInc);
                double timeOrigin = t.getGraphHeight() * secondHeight + PAD;
                double trackHeight = duration * secondHeight;
                graph.setColor(color);
                // System.out.println("PLOTTING TRACK, " + day + ", " +
                // dayOrigin + ", " + t.getGraphHeight() + ", " + timeOrigin
                // + ", " + trackHeight);
                // graph.draw(new Rectangle2D.Double(dayOrigin, timeOrigin,
                // xInc, trackHeight));
                graph.fillRect((int) dayOrigin, (int) timeOrigin,
                        (int) xInc, (int) trackHeight);
            }

        }

        for (int i = 0; i < graphData.dayMax;){
            graph.draw(new Line2D.Double(x0 - i * xInc, PAD, x0 - i * xInc, graphHeight + PAD));
            i = i + 7;
        }

    }
}
public void zoom(int zoom){
    this.zoom = zoom;
    repaint();
}

}

它创建一个Graphics2D对象，在该对象上绘制一个大的轮廓矩形，然后将每个轨道矩形绘制到此Graphics2D图形对象的某个位置。现在我已经删除了setPreferredSize as recommended here的使用但现在我遇到的问题是当我手动将GraphPanel中的graphHeight设置为高度为6000时，graphScrollPanel没有意识到它包含的graphPanel实际上是更大的所有graphHeight正在绘制一个~6000px高的矩形。那么在这种情况下我应该使用setPreferredSize还是有另一种方法来设置Graphics2D对象的大小？

Answer 1

请勿致电updateUI这与UI外观和API相关，与重新绘制无关。

您尝试/正在使用哪些布局管理器？

调用invalidate()，repaint()应该影响父容器布局管理器并使它们相应地重新布局组件，但是你需要记住，布局管理器只使用min / max / pref尺寸信息作为指南。

我的例子中最好的客人是你应该试着打电话

outputGUIView.graphPanel.invalidate();
outputGUIView.graphPanel.repaint();

和/或

outputGUIView.invalidate();
outputGUIView.repaint();

在滚动窗格中调用invalidate可能不会实现很多，因为视口负责布局内容，而不是滚动窗格。

如果你真的很绝望，你可以试试

outputGUIView.graphScrollPanel.getViewport().invalidate();
outputGUIView.graphScrollPanel.getViewport().repaint();

Java updateUI只工作一次

1 个答案: