能说下我的paint()方法为什么没有被执行嘛，最好能详细点。paint()方法好像是自动被调用的。我写代码画不出东西来。帮调试下，说明下原因。非常感谢！！！
- Java code
import java.awt.*;import java.awt.event.*;public class TestGraphics1 extends Frame{ Frame f; Button b1; Button b2; TestGraphics1() { b1 = new Button("Draw Line"); b2 = new Button("Draw circle"); f = new Frame("Draw Graphics"); f.setBounds(300,300,500,400); f.setVisible(true); f.setLayout(new FlowLayout()); f.add(b1); f.add(b2); f.addWindowListener(new Monitor()); } public void paint(Graphics g) { Color c = g.getColor(); g.setColor(Color.RED); g.drawLine(10,10,20,30); g.setColor(c); } class Monitor extends WindowAdapter { public void windowClosing(WindowEvent e) { System.exit(0); } } public static void main(String []args) { TestGraphics1 tg = new TestGraphics1(); }}------解决方案--------------------
TestGraphics1中的paint()方法不是f的paint()方法，另外，你画的线会与标题栏重合绝大部分
- Java code
import java.awt.*;import java.awt.event.*;public class TestGraphics1 extends Frame{ Frame f; Button b1; Button b2; TestGraphics1() { super("Draw Graphics"); b1 = new Button("Draw Line"); b2 = new Button("Draw circle"); setBounds(300,300,500,400); setLayout(new FlowLayout()); add(b1); add(b2); addWindowListener(new Monitor()); setVisible(true); //下面的paint()方法是TestGraphics1.this的paint方法，而不是f的 /*f = new Frame("Draw Graphics"); f.setBounds(300,300,500,400); f.setVisible(true); f.setLayout(new FlowLayout()); f.add(b1); f.add(b2); f.addWindowListener(new Monitor());*/ } public void paint(Graphics g) { Color c = g.getColor(); g.setColor(Color.RED); g.drawLine(100,100,20,30); //g.drawLine(10,10,20,30);坐标与标题栏重合了，如果仔细看的话，还是能在左上方看到一个红点的。。。 g.setColor(c); } class Monitor extends WindowAdapter { public void windowClosing(WindowEvent e) { System.exit(0); } } public static void main(String []args) { TestGraphics1 tg = new TestGraphics1(); }}