用Java在图像上绘制字符串

Question

I need to draw a string to a BufferedImage in Java. The way this is done doesn't matter, however the image should take up only the space it needs, like in the example below. I need a new BufferedImage created containing only the string. Extra space above the string and on the right side of the string could be tolerated, but I can't have extra space below and left of the drawn string.

Is something like this possible? I have tried to do it myself, but I always end up having extra space which is not what I want. Any help would be appreciated.

Answer 1

You can use Graphics2D#drawString method:

import java.awt.Container;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;

import javax.swing.JComponent;
import javax.swing.JFrame;

public class MainClass{
  public static void main(String[] args) {
    JFrame jf = new JFrame("Demo");
    Container cp = jf.getContentPane();
    MyCanvas tl = new MyCanvas();
    cp.add(tl);
    jf.setSize(300, 200);
    jf.setVisible(true);
  }
}

class MyCanvas extends JComponent {
  public void paint(Graphics g) {
    Graphics2D g2 = (Graphics2D)g;
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
        RenderingHints.VALUE_ANTIALIAS_ON);
    Font font = new Font("Serif", Font.PLAIN, 96);
    g2.setFont(font);

    g2.drawString("Test string", 40, 120); 
  }
}

Answer 2

I need to draw a string to an image in Java. I have tried to do it myself, but I always end up having extra space

I can't tell if you are trying to create an image of a String or add some text to an existing image. Since you say you have extra space I assume you are trying to create an image of the text and you don't know how big to make the BufferedImage that you are drawing on.

Create a JLabel with the text you want. Then you can use the Screen Image class to create an image of the label component. The the image will be the exact size pf the text.