java - 如何在 Java 中使用 Canvas 根据屏幕宽度和高度绘制字符串或矩形

Question

我想知道如何绘制字符串或矩形（JFrame 完全处于全屏状态）

这是我的 Main.java 类中的内容：

public static int WIDTH, HEIGHT;
private Window window;
...
public Main() {
    window = new Window("2D Shooter", this);
...
    private void render(){
    BufferStrategy bs = this.getBufferStrategy();

    if(bs == null){
        this.createBufferStrategy(3);
        return;
    }

    Graphics g = bs.getDrawGraphics();

    g.setColor(Color.BLACK);
    g.fillRect(0, 0, WIDTH, HEIGHT);

    handler.render(g);//this calls the render method to render objects

    g.dispose();
    bs.show();
}

后来在不同的课程中，我有：

public void render(Graphics g){
    ...
    g.setColor(Color.WHITE);
    g.drawString("2D Shooter", ((Main.WIDTH)/2), (Main.HEIGHT/5));
    ...

}

此代码有效并运行但文本未完全居中我希望它居中在顶部而不是在中间。谢谢你！

Answer 1

使用图形上下文的FontMetrics.

String s = "2D Shooter";
int w2 = g.getFontMetrics().stringWidth(s) / 2;
int h2 = g.getFontMetrics().getHeight();
g.drawString(s, getWidth() / 2 - w2, h2);

import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;

/**
 * @see http://stackoverflow.com/a/37150783/230513
 */
public class Test {

    private void display() {
        JFrame f = new JFrame("Test");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(new JPanel() {
            @Override
            protected void paintComponent(Graphics g) {
                super.paintComponent(g);
                g.setFont(getFont().deriveFont(Font.BOLD, 24f));
                String s = "2D Shooter";
                int w2 = g.getFontMetrics().stringWidth(s) / 2;
                int h2 = g.getFontMetrics().getHeight();
                g.drawString(s, getWidth() / 2 - w2, h2);
            }

            @Override
            public Dimension getPreferredSize() {
                return new Dimension(320, 240);
            }
        });
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Test()::display);
    }
}