UC知道java 这段代码怎么显示不了图形
来源：百度知道 编辑：UC知道 时间：2024/05/13 05:55:41
import javax.swing.*;
import java.awt.*;
class Picture{
public static void main(String[] args){
JFrame win;
Container contentPane;
Graphics g;
win= new JFrame("My First Rectangle");
win.setSize(300,200);
win.setLocation(100,100);
win.setVisible(true);
contentPane= win.getContentPane();
g=contentPane.getGraphics();
g.setColor(Color.BLUE);
g.drawRect(0,0,30,30);
g.drawRoundRect(50,50,50,50,20,20);
g.fillRect(175,50,100,30);
}
}
import java.awt.*;
class Picture{
public static void main(String[] args){
JFrame win;
Container contentPane;
Graphics g;
win= new JFrame("My First Rectangle");
win.setSize(300,200);
win.setLocation(100,100);
win.setVisible(true);
contentPane= win.getContentPane();
g=contentPane.getGraphics();
g.setColor(Color.BLUE);
g.drawRect(0,0,30,30);
g.drawRoundRect(50,50,50,50,20,20);
g.fillRect(175,50,100,30);
}
}
不是这样子的
是用paint(Griphics g)
{
g.setColor(Color.BLUE);
g.drawRect(0,0,30,30);
g.drawRoundRect(50,50,50,50,20,20);
g.fillRect(175,50,100,30);
}
这个paint方法是系统自动调用的...它是容器的方法..
所以一般用JPanel或者Container
////在paint()里画
import javax.swing.*;
import java.awt.*;
class Picture{
public static void main(String[] args){
JFrame win;
win= new JFrame("My First Rectangle"){
public void paint(Graphics g){
g.drawRect(0,0,30,30);
g.drawRoundRect(50,50,50,50,20,20);
g.fillRect(175,50,100,30);
}
};
win.setSize(300,200);
win.setLocation(100,100);
win.setVisible(true);
}
}
你需要加一个方法
public void paint(Graphics g)
{
}
将你的绘图的代码放到这里面，不用显示的调用。
它会自己调用的