Java 示例 - 创建框架

• 

  问题描述

  如何在新框架中显示消息？
• 

  解决方案

  以下示例演示了如何通过使用 JFrame() 创建框架并使用 JFrames getContentPanel()、setSize() 和 setVisible() 方法来显示此框架，从而在新框架中显示消息。

  
  import java.awt.*;
  import java.awt.font.FontRenderContext;
  import java.awt.geom.Rectangle2D;
  import javax.swing.JFrame;
  import javax.swing.JPanel;
  public class Main extends JPanel {
     public void paint(Graphics g) {
        Graphics2D g2 = (Graphics2D) g;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        g2.setFont(new Font("Serif", Font.PLAIN, 48));
        paintHorizontallyCenteredText(g2, "Java Source", 200, 75);
        paintHorizontallyCenteredText(g2, "and", 200, 125);
        paintHorizontallyCenteredText(g2, "Support", 200, 175);
     }
     protected void paintHorizontallyCenteredText(
        Graphics2D g2, String s, float centerX, float baselineY) {
        
        FontRenderContext frc = g2.getFontRenderContext();
        Rectangle2D bounds = g2.getFont().getStringBounds(s, frc);
        float width = (float) bounds.getWidth();
        g2.drawString(s, centerX - width / 2, baselineY);
     }
     public static void main(String[] args) {
        JFrame f = new JFrame();
        f.getContentPane().add(new Main());
        f.setSize(450, 350);
        f.setVisible(true);
     }
  }
  

• 

  结果

  上面的代码示例将产生以下结果。

  
  JAVA and J2EE displayed in a new Frame.
  

  以下是在新框架中显示消息的示例。

  
  import java.awt.BorderLayout;
  import java.awt.Button;
  import java.awt.Component;
  import java.awt.Frame;
  import java.awt.TextArea;
  public class Main {
     public static void main(String[] args) {
        Frame f = new Frame("Tutorialspoint");
        Component text = new TextArea("Sairamkrishna Mamamahe");
        Component button = new Button("Button");
        f.add(text, BorderLayout.NORTH);
        f.add(button, BorderLayout.SOUTH);
        int width = 300;
        int height = 300;
        f.setSize(width, height);
        f.setVisible(true);
     } 
  }