如何在Java中居中显示Graphics.drawString()?

时间:2014-12-30 13:15:41

标签: java text draw centering graphics2d

我正在为我的 Java 游戏开发菜单系统,我想知道如何将Graphics.drawString()中的文本居中,这样如果我想绘制一个文本,中心点位于X: 50Y: 50,文字宽30像素,10像素高,文字将从X: 35开始,{{1 }}

我可以在绘制之前确定文字的宽度吗? 那么数学很容易。

编辑:我也想知道我是否可以获得文字的高度,这样我也可以垂直居中。

感谢任何帮助!

3 个答案:

答案 0 :(得分:55)

我在this question上使用了答案。

我使用的代码看起来像这样:

/**
 * Draw a String centered in the middle of a Rectangle.
 *
 * @param g The Graphics instance.
 * @param text The String to draw.
 * @param rect The Rectangle to center the text in.
 */
public void drawCenteredString(Graphics g, String text, Rectangle rect, Font font) {
    // Get the FontMetrics
    FontMetrics metrics = g.getFontMetrics(font);
    // Determine the X coordinate for the text
    int x = rect.x + (rect.width - metrics.stringWidth(text)) / 2;
    // Determine the Y coordinate for the text (note we add the ascent, as in java 2d 0 is top of the screen)
    int y = rect.y + ((rect.height - metrics.getHeight()) / 2) + metrics.getAscent();
    // Set the font
    g.setFont(font);
    // Draw the String
    g.drawString(text, x, y);
}

答案 1 :(得分:2)

当我必须绘制文本时,我通常需要将文本居中在一个边界矩形中。

/**
 * This method centers a <code>String</code> in 
 * a bounding <code>Rectangle</code>.
 * @param g - The <code>Graphics</code> instance.
 * @param r - The bounding <code>Rectangle</code>.
 * @param s - The <code>String</code> to center in the
 * bounding rectangle.
 * @param font - The display font of the <code>String</code>
 * 
 * @see java.awt.Graphics
 * @see java.awt.Rectangle
 * @see java.lang.String
 */
public void centerString(Graphics g, Rectangle r, String s, 
        Font font) {
    FontRenderContext frc = 
            new FontRenderContext(null, true, true);

    Rectangle2D r2D = font.getStringBounds(s, frc);
    int rWidth = (int) Math.round(r2D.getWidth());
    int rHeight = (int) Math.round(r2D.getHeight());
    int rX = (int) Math.round(r2D.getX());
    int rY = (int) Math.round(r2D.getY());

    int a = (r.width / 2) - (rWidth / 2) - rX;
    int b = (r.height / 2) - (rHeight / 2) - rY;

    g.setFont(font);
    g.drawString(s, r.x + a, r.y + b);
}

答案 2 :(得分:0)

我确实创建了一个函数来将文本保留在图像的中心

    private static void setTextCenter(Graphics2D graphics2DImage, String string,
                                        BufferedImage bgImage) {
    int stringWidthLength = (int)
            graphics2DImage.getFontMetrics().getStringBounds(string, graphics2DImage).getWidth();
    int stringHeightLength = (int)
            graphics2DImage.getFontMetrics().getStringBounds(string, graphics2DImage).getHeight();

    int horizontalCenter = bgImage.getWidth() / 2 - stringWidthLength / 2;
    int verticalCenter = bgImage.getHeight() / 2 - stringHeightLength / 2;
    graphics2DImage.drawString(string, horizontalCenter, verticalCenter);
}

graphics2DImage在哪里。

Graphics2D graphics2DImage = bgImage.createGraphics();
graphics2DImage.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
            RenderingHints.VALUE_ANTIALIAS_ON);

    graphics2DImage.drawImage(bgImage, 0, 0, null);