java - 获取使用 JLabel 创建的图像的 "native size"

Question

I am using JLabel从字符串创建图像文件。

我必须指定图像尺寸 (label.setSize(width, height))，否则会出现异常:

java.lang.IllegalArgumentException: Width (0) and height (0) cannot be <= 0
    at java.awt.image.DirectColorModel.createCompatibleWritableRaster(DirectColorModel.java:1016)
    at java.awt.image.BufferedImage.<init>(BufferedImage.java:338)
    at com.shopsnips.portal.services.ImageCreator.createFromText(ImageCreator.java:31)
    at com.shopsnips.portal.services.ImageCreator.main(ImageCreator.java:18)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)

我可以使用

控制字体大小

label.setFont(new Font("Serif", Font.BOLD, 26));

当我使用太大而不适合固定尺寸的字体或文本时，标签会被截断并包含“...”。有没有办法确定仍适合我设置的尺寸的最佳/最大字体大小？

或者，我如何确定当前设置(字体大小 + 尺寸)是否会导致文本被截断？

这是一些来源:

import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.nio.file.Path;
import java.nio.file.Paths;

public class ImageCreator {
    private ImageCreator(){}

    private final static String FONT = "Freestyle Script";

    public static void main(String[] args) {
        Path outputFile = Paths.get("c:\\tmp\\img\\test.png");

        createFromText("Hello World - this is a long text", outputFile, 150, 50);
    }

    /**
* <p>Create an image from text. <p/>
* <p/>
* https://stackoverflow.com/a/4437998/11236
*/
    public static void createFromText(String text, Path outputFile, int width, int height) {
        JLabel label = new JLabel(text, SwingConstants.CENTER);
        label.setSize(width, height);
        label.setFont(new Font(FONT, Font.BOLD, 24));

        BufferedImage image = new BufferedImage(
                label.getWidth(), label.getHeight(),
                BufferedImage.TYPE_INT_ARGB);

        Graphics g = null;
        try {
            // paint the html to an image
            g = image.getGraphics();
            g.setColor(Color.BLACK);
            label.paint(g);
        } finally {
            if (g != null) {
                g.dispose();
            }
        }

        // get the byte array of the image (as jpeg)
        try {
            ImageIO.write(image, "png", outputFile.toFile());
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
}

请登录后发表评论。

Answer 1

1) 将BuferedImage 设为Icon到 JLabel ,

2) 不要setSize让这个作业为LayoutManager

3) @Jeffrey 的回答太接近正确答案，BuferedImage 如果存在可以返回两个维度

4) 为了尽快获得更好的帮助，请发布 SSCCE ，因为我/我们在您的监视器上看不到代码，也看不到您的 Java 类生成的异常