我使用对象stringWidth("str")上的方法计算字符串的宽度。这种方法只给了我基线FontMetrics上从起点到终点的宽度。不是字符串的整体宽度。
关于如何计算整体宽度的任何想法？
大多数文档都说我不能通过添加字符串中每个字符的宽度来依赖结果。到目前为止，这是我的代码：
BufferedImage image = new BufferedImage(1, 1, BufferedImage.TYPE_INT_ARGB);
Graphics2D g = image.createGraphics();
FontMetrics fm = g.getFontMetrics(new Font("Arial", Font.PLAIN, 6));
int width = fm.stringWidth("Product name");
FontMetrics 也有 getStringBounds()，而不仅仅是 stringWidth()。
你应该问问自己你需要什么文本宽度。如果它是通过例如paintComponent() 覆盖进行输出，那么您应该测量那里的文本尺寸，以确保考虑所有因素（例如分数度量、抗锯齿）。此外，您不必考虑处置图形上下文 - 在您的示例中，您绝对必须这样做，它需要 g.dispose()！
以下示例用于 paintComponent() 覆盖，例如，对于您用作 ContentPane 的 JPanel，以您给定的字体在组件的中心绘制文本，并在其周围绘制一个有一定距离的矩形，文本完全位于其中心。
然而，文本大小，尤其是垂直大小，并不精确。更好的解决方案是进一步下降。
这个不精确的解决方案的屏幕截图：http: //i.imgur.com/vetRjCK.png
进一步向下精确解决方案的屏幕截图：http: //i.imgur.com/0A0EdCf.png
final int w = getWidth();
final int h = getHeight();
// CLEAR BACKGROUND
g.setColor(Color.DARK_GRAY);
g.fillRect(0, 0, w, h);
// ACTIVATE ANTIALIASING AND FRACTIONAL METRICS
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g.setRenderingHint(RenderingHints.KEY_FRACTIONALMETRICS, RenderingHints.VALUE_FRACTIONALMETRICS_ON);
// PREPARE TEXT, COLOR, FONT
final String text = "The Higgs Boson is ...";
g.setColor(Color.ORANGE);
g.setFont(yourFont);
// PREPARE COORDINATES, AND DRAW TEXT
final FontMetrics fm = g.getFontMetrics();
final Rectangle2D stringBounds = fm.getStringBounds(text, g);
final double x = (w - stringBounds.getWidth()) / 2d;
final double y = (h - stringBounds.getHeight()) / 2d;
g.drawString(text, (int) x, (int) (y + fm.getAscent()));
// TURN OFF ANTIALIASING FOR HIGHER VISUAL PRECISION OF THE LINES
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_OFF);
// DRAW RECTANGLE BORDER
final double borderDistance = 10d;
final Shape borderRect = new Rectangle2D.Double(x - borderDistance * 2, y - borderDistance, stringBounds.getWidth() + borderDistance * 4, stringBounds.getHeight() + borderDistance * 2);
g.setStroke(new BasicStroke(3f));
g.draw(borderRect);
// DRAW THIN TIGHT RECTANGLE BORDER
final Shape borderRectTight = new Rectangle2D.Double(x, y , stringBounds.getWidth(), stringBounds.getHeight());
g.setStroke(new BasicStroke(1f));
g.setColor(Color.GRAY);
g.draw(borderRectTight);
以下解决方案在结构上与上述类似，但不是使用 FontMetrics 调用来松散地导出文本尺寸，而是通过首先将文本转换为 Shape来导出精确的文本尺寸。
// CLEAR BACKGROUND
g.setColor(Color.DARK_GRAY);
g.fillRect(0, 0, w, h);
// ACTIVATE ANTIALIASING AND FRACTIONAL METRICS
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g.setRenderingHint(RenderingHints.KEY_FRACTIONALMETRICS, RenderingHints.VALUE_FRACTIONALMETRICS_ON);
// PREPARE TEXT, COLOR
final String text = "The Higgs Boson is ...";
g.setColor(Color.ORANGE);
// CREATE GLYPHVECTOR FROM TEXT, CREATE PRELIMINARY SHAPE FOR COORDINATE CALCULATION, CALC COORDINATES
final GlyphVector gv = yourFont.createGlyphVector(g.getFontRenderContext(), text);
final Rectangle2D stringBoundsForPosition = gv.getOutline().getBounds2D();
final double xForShapeCreation = (w - stringBoundsForPosition.getWidth()) / 2d;
final double yForShapeCreation = (h - stringBoundsForPosition.getHeight()) / 2d;
// DERIVE SHAPE AGAIN, THIS TIME IN THE RIGHT PLACE (IT'S NOT THE ONLY POSSIBLE METHOD.)
final Shape textShape = gv.getOutline((float) xForShapeCreation, (float) yForShapeCreation + g.getFontMetrics(yourFont).getAscent());
g.fill(textShape);
// GET PRECISE SHAPE BOUNDS, TURN OFF ANTIALIASING FOR HIGHER VISUAL PRECISION OF THE LINES
final Rectangle2D stringBoundsForEverything = textShape.getBounds2D();// JavaDocs: "Returns a high precision [...] bounding box of the Shape [...] guarantee [...] that the Shape lies entirely within the indicated Rectangle2D."
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_OFF);
// DRAW RECTANGLE BORDER
final double borderDistance = 10d;
final Shape borderRect = new Rectangle2D.Double(stringBoundsForEverything.getX() - borderDistance * 2, stringBoundsForEverything.getY() - borderDistance, stringBoundsForEverything.getWidth() + borderDistance * 4, stringBoundsForEverything.getHeight() + borderDistance * 2);
g.setStroke(new BasicStroke(3f));
g.draw(borderRect);
// DRAW THIN TIGHT RECTANGLE BORDER
final Shape borderRectTight = new Rectangle2D.Double(stringBoundsForEverything.getX(), stringBoundsForEverything.getY(), stringBoundsForEverything.getWidth(), stringBoundsForEverything.getHeight());
g.setStroke(new BasicStroke(1f));
g.setColor(Color.GRAY);
g.draw(borderRectTight);
你需要一个图形对象。
graphics.setFont(font);
int lenghtgraphics.getFontMetrics(graphics.getFont()).stringWidth(value);
几年前我构建了一个 xml 渲染组件并且非常依赖
SwingUtilities.computeStringWidth(fontMetrics, string);
我从要为其测量字符串的组件中获取字体指标。
myComponent.getFontMetrics(myComponent.getFont());