本文实例讲述了Android编程之绘制文本（FontMetrics）实现方法。分享给大家供大家参考，具体如下：
Canvas 作为绘制文本时，使用FontMetrics对象，计算位置的坐标。
它的思路和java.awt.FontMetrics的基本相同。
FontMetrics对象
它以四个基本坐标为基准，分别为：
FontMetrics.top
FontMetrics.ascent
FontMetrics.descent
FontMetrics.bottom
该图片将如下
代码如下：
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Paint textPaint = new Paint( Paint.ANTI_ALIAS_FLAG); textPaint.setTextSize( 35); textPaint.setColor( Color.WHITE); // FontMetrics对象 FontMetrics fontMetrics = textPaint.getFontMetrics(); String text = "abcdefghijklmnopqrstu"; // 计算每一个坐标 float baseX = 0; float baseY = 100; float topY = baseY + fontMetrics.top; float ascentY = baseY + fontMetrics.ascent; float descentY = baseY + fontMetrics.descent; float bottomY = baseY + fontMetrics.bottom; // 绘制文本 canvas.drawText( text, baseX, baseY, textPaint); // BaseLine描画 Paint baseLinePaint = new Paint( Paint.ANTI_ALIAS_FLAG);> baseLinePaint.setColor( Color.RED); canvas.drawLine(0, baseY, getWidth(), baseY, baseLinePaint); // Base描画 canvas.drawCircle( baseX, baseY, 5, baseLinePaint); // TopLine描画 Paint topLinePaint = new Paint( Paint.ANTI_ALIAS_FLAG); topLinePaint.setColor( Color.LTGRAY); canvas.drawLine(0, topY, getWidth(), topY, topLinePaint); // AscentLine描画 Paint ascentLinePaint = new Paint( Paint.ANTI_ALIAS_FLAG); ascentLinePaint.setColor( Color.GREEN); canvas.drawLine(0, ascentY, getWidth(), ascentY, ascentLinePaint); // DescentLine描画 Paint descentLinePaint = new Paint( Paint.ANTI_ALIAS_FLAG); descentLinePaint.setColor( Color.YELLOW); canvas.drawLine(0, descentY, getWidth(), descentY, descentLinePaint); // ButtomLine描画 Paint bottomLinePaint = new Paint( Paint.ANTI_ALIAS_FLAG); bottomLinePaint.setColor( Color.MAGENTA); canvas.drawLine(0, bottomY, getWidth(), bottomY, bottomLinePaint); |
希望本文所述对大家Android程序设计有所帮助。
