JAVA Graphics2D 制图 透明色

[暗夜螃蟹]

//JAVA 用 Graphics2D 制图 想把生成的图片变成透明色，不知道如何实现；请教高手！~~
public class WordToPic {

	//    
	public static int getLength(String text) {
		int length = 0;
		for (int i = 0; i < text.length(); i++) {
			if (new String(text.charAt(i) + "").getBytes().length > 1) {
				length += 2;
			} else {
				length += 1;
			}
		}
		return length / 2;
	}

	public static String TextToPic(String text, int width, int height,
			int fontSize) {
		try {
			String filepath = "D:/apache-tomcat-5.5.17/webapps/webapp/UserFiles/Image/texttopic/image"
					+ getDate() + ".png";

			// String
			// filepath="/www/newaudi_cms/app/UserFiles/Image/texttopic/image"+getDate()+".png";

			File file = new File(filepath);

			// Font font = new Font("甲骨文", 36, fontSize);
		
			System.out.println("topic=" + text);
			Font font = new Font("汉仪双线简体", Font.BOLD, fontSize);
			// Font font = new Font("新宋体", Font.BOLD, fontSize);
			BufferedImage bi = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);
			Graphics2D g2 = (Graphics2D) bi.getGraphics();
			//g2.setBackground(new Color(0,0xFF,0xFF,0xFF));
			g2.setBackground(new Color(0,0xFF,0xFF,0xFF));
			g2.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
			g2.clearRect(0, 0, width, height);
			g2.setFont(font);
			g2.setPaint(Color.black);
			g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP,0.3f));
			//
		    AlphaComposite ac = AlphaComposite.getInstance(AlphaComposite.SRC_OVER , 0.5f);
		    g2.setComposite(ac);

			
			// g2.drawString(text, fontSize, fontSize);
			paintString(g2, text,2,42, fontSize);
			g2.dispose();
			ImageIO.write(bi, "png", file);
			return "image" + getDate() + ".png";

		} catch (Exception e) {
			e.printStackTrace();
		}
		return "";
	}

	public static String getDate() {
		SimpleDateFormat formatter = new SimpleDateFormat("yyyyMMddHHmmss");

		return formatter.format(new Date());
	}

	private static void paintString(Graphics2D g2d, String str, int x, int y,
			int fontSize) {
		FontMetrics metrics = g2d.getFontMetrics();
		for (char ca : str.toCharArray()) {
			int px = metrics.stringWidth("" + ca);
			g2d.drawString("" + ca, x + (fontSize - px) / 2, y);
			x += fontSize;
		}
	}

	 public static Date parsePlainDate(String source) {
		 SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmss");

		 return sdf.parse(source, new ParsePosition(0));
	}


	public static void main(String[] args) throws IOException, ParseException {
		// pressText("我是文字", "d:\\1.bmp", "黑体", 36, Color.white, 80, 0, 0,
		// 0.3f);
		TextToPic("我是文字", 500, 100, 50);
		//
		System.out.print(parsePlainDate(getDate()));
	}

}

[sunyiz]

import java.awt.Color;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.text.ParseException;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Date;

import javax.imageio.ImageIO;

public class WordToPic {

    //    
    public static int getLength(String text) {
        int length = 0;
        for (int i = 0; i < text.length(); i++) {
            if (new String(text.charAt(i) + "").getBytes().length > 1) {
                length += 2;
            } else {
                length += 1;
            }
        }
        return length / 2;
    }

    public static String TextToPic(String text, int width, int height,
            int fontSize) {
        try {
            String filepath = "D:/apache-tomcat-5.5.17/webapps/webapp/UserFiles/Image/texttopic/image"
                    + getDate() + ".png";

            // String
            // filepath="/www/newaudi_cms/app/UserFiles/Image/texttopic/image"+getDate()+".png";

            File file = new File(filepath);

            // Font font = new Font("甲骨文", 36, fontSize);
        
            System.out.println("topic=" + text);
            Font font = new Font("汉仪双线简体", Font.BOLD, fontSize);
            // Font font = new Font("新宋体", Font.BOLD, fontSize);
            BufferedImage bi = new BufferedImage(width, height,BufferedImage.TYPE_4BYTE_ABGR);
            Graphics2D g2 = (Graphics2D) bi.getGraphics();

            g2.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
            g2.setFont(font);
            g2.setPaint(Color.black);

            paintString(g2, text,2,42, fontSize);
            g2.dispose();
            ImageIO.write(bi, "png", file);
            return "image" + getDate() + ".png";

        } catch (Exception e) {
            e.printStackTrace();
        }
        return "";
    }

    public static String getDate() {
        SimpleDateFormat formatter = new SimpleDateFormat("yyyyMMddHHmmss");

        return formatter.format(new Date());
    }

    private static void paintString(Graphics2D g2d, String str, int x, int y,
            int fontSize) {
        FontMetrics metrics = g2d.getFontMetrics();
        for (char ca : str.toCharArray()) {
            int px = metrics.stringWidth("" + ca);
            g2d.drawString("" + ca, x + (fontSize - px) / 2, y);
            x += fontSize;
        }
    }

     public static Date parsePlainDate(String source) {
         SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmss");

         return sdf.parse(source, new ParsePosition(0));
    }


    public static void main(String[] args) throws IOException, ParseException {
        // pressText("我是文字", "d:\\1.bmp", "黑体", 36, Color.white, 80, 0, 0,
        // 0.3f);
        TextToPic("我是文字", 500, 100, 50);
        //
        System.out.print(parsePlainDate(getDate()));
    }

}

貌似这样就OK了…………

[暗夜螃蟹]

总是这么急时出现，哇哈哈

[暗夜螃蟹]

生成的是黑色的背景。。。。

[sunyiz]

你用ps打开看看……
别用window自带的画图工具……那个是不能编辑透明像素的

[暗夜螃蟹]

真是太谢谢了