Question

我正在Netbeans中开发一个Java程序，以绘制一个图形树，以创建其节点和边缘并将其绘制到JPanel中。

我只能拖拽节点和边缘，因为图像没有更新-它突然消失了一切，我需要添加节点或边缘以再次观看树。

我发现该错误一定是在Graph.paint（）函数中或有关重绘，重新验证...函数的某个东西。

我一直在这里寻找解决方案，但找不到任何真正能解决问题的方法。

GraphPanel 是管理Graph的JPanel。

图是存储所有节点和边的结构

节点和边缘分别是节点和边缘的结构。

我的 GraphPanelMouseClicked 代码是：我发布了这段代码以向我展示如何绘制节点，等等[这可以正常工作

private void GraphPanelMouseClicked(java.awt.event.MouseEvent evt) {                                        
    // TODO add your handling code here:
    System.out.println("Click X: " + evt.getX() + " , y: " + evt.getY());
    System.out.println("Click On Screen X: " + evt.getXOnScreen() + " , y: " + evt.getYOnScreen());

    switch(this.ButtonSelection){
        case OriHelperGUI.Select:
            break;
        case OriHelperGUI.AddNode:
            String name = JOptionPane.showInputDialog("Node name: ");
            String weight = JOptionPane.showInputDialog("Node weight: ");
            Node n = new Node(new Point(evt.getX(), evt.getY()), Integer.parseInt(weight), name);
            g.addNode(n);
            System.out.println("Nodo " + name + " añadido");
            break;
        case OriHelperGUI.AddEdge:
                for(Node node: g.getNodes()){
                    if(new Rectangle((int)(node.getPoint().getX() - node.getWeight()/2),(int)(node.getPoint().getY() - node.getWeight()/2), (int)node.getWeight(), (int)node.getWeight()).contains(new Point(evt.getX(), evt.getY()))){
                       if(this.AddEdgeN1==null){
                           AddEdgeN1 = node; 
                           System.out.println(node.getName());
                       }
                       else{
                           if(AddEdgeN2==null){
                               AddEdgeN2 = node;
                               System.out.println("Uniendo " + AddEdgeN1.getName() + " a " + AddEdgeN2.getName());
                               g.addEdge(new Edge(AddEdgeN1, AddEdgeN2));
                               AddEdgeN1.addNeighbour(AddEdgeN2);
                               AddEdgeN2.addNeighbour(AddEdgeN1);
                               g.checkEdges();
                               AddEdgeN1 = null;
                               AddEdgeN2 = null;
                           }                               
                       }
                    }
                }                   
            break;
        default:
            break;
    }
    g.paint(GraphPanel.getGraphics());
    GraphPanel.revalidate();

}

我的 GraphPanelMouseDragged 代码是：我认为这是失败的地方...

 private void GraphPanelMouseDragged(java.awt.event.MouseEvent evt) {                                        
    // TODO add your handling code here:
    if(this.SelectedNode>=0){
        Node old = this.g.getNodes().get(this.SelectedNode);
        Node n = new Node(new Point(evt.getX(),evt.getY()),old.getWeight(),old.getName());            
        g.getNodes().set(this.SelectedNode, n);
        g.paint(GraphPanel.getGraphics());
        GraphPanel.revalidate();
    }
}

我的 Graph paint（g）和paintComponent（g）方法是[不确定更新图像时哪个方法可以工作]：

@Override
public void paint(Graphics g){
    g.setColor(Color.black);
    super.paint(g);
    for(Node n:nodes){
        n.paintNode(g);
    }
    for(Edge e:edges){
        e.paintEdge(g);
    }
}

public void paintComponent(Graphics g){
    g.setColor(Color.black);
    super.paint(g);
    for(Node n:nodes){
        n.paintNode(g);
    }
    for(Edge e:edges){
        e.paintEdge(g);
    }
}

节点绘制（g）方法：

public void paintNode(Graphics g) {
    super.paint(g); // don't forget to call the super's method
    g.drawOval((int)(point.x -(weight/2)), (int)(point.y-(weight/2)), (int)weight, (int)weight);
    g.drawString(name, point.x, point.y);
}

@Override
public void paintComponent(Graphics g) {
    super.paint(g); // don't forget to call the super's method
    g.drawOval((int)(point.x -(weight/2)), (int)(point.y-(weight/2)), (int)weight, (int)weight);
    g.drawString(name, point.x, point.y);
    repaint();
}

最后，我的 Edge 绘画方法是：

public void paintEdge(Graphics g) {
    super.paint(g); // don't forget to call the super's method
    g.drawLine((int)n1.getPoint().getX(), (int)n1.getPoint().getY(), (int)n2.getPoint().getX(), (int)n2.getPoint().getY());
}

@Override
public void paintComponent(Graphics g) {
    super.paint(g); // don't forget to call the super's method
    g.drawLine((int)n1.getPoint().getX(), (int)n1.getPoint().getY(), (int)n2.getPoint().getX(), (int)n2.getPoint().getY());
    repaint();
}

我还添加了当前程序的GIF，以更好地理解我的问题。

非常感谢您

拖动鼠标时动态绘制对象

0 个答案: