Android編程之繪製文本（FontMetrics）實現方法_Android

本文執行個體講述了Android編程之繪製文本（FontMetrics）實現方法。分享給大家供大家參考，具體如下：

Canvas 作為繪製文本時，使用FontMetrics對象，計算位置的座標。

它的思路和java.awt.FontMetrics的基本相同。

FontMetrics對象

它以四個基本座標為基準，分別為：

FontMetrics.top
FontMetrics.ascent
FontMetrics.descent
FontMetrics.bottom

該圖片將如下

代碼如下：

Paint textPaint = new Paint( Paint.ANTI_ALIAS_FLAG); textPaint.setTextSize( 35); textPaint.setColor( Color.WHITE); // FontMetrics對象 FontMetrics fontMetrics = textPaint.getFontMetrics(); String text = "abcdefghijklmnopqrstu"; // 計算每一個座標 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; // 繪製文本 canvas.drawText( text, baseX, baseY, textPaint); // BaseLine描畫 Paint baseLinePaint = new Paint( Paint.ANTI_ALIAS_FLAG);> baseLinePaint.setColor( Color.RED); canvas.drawLine(0, baseY, getWidth(), baseY, baseLinePaint); // Base描畫 canvas.drawCircle( baseX, baseY, 5, baseLinePaint); // TopLine描畫 Paint topLinePaint = new Paint( Paint.ANTI_ALIAS_FLAG); topLinePaint.setColor( Color.LTGRAY); canvas.drawLine(0, topY, getWidth(), topY, topLinePaint); // AscentLine描畫 Paint ascentLinePaint = new Paint( Paint.ANTI_ALIAS_FLAG); ascentLinePaint.setColor( Color.GREEN); canvas.drawLine(0, ascentY, getWidth(), ascentY, ascentLinePaint); // DescentLine描畫 Paint descentLinePaint = new Paint( Paint.ANTI_ALIAS_FLAG); descentLinePaint.setColor( Color.YELLOW); canvas.drawLine(0, descentY, getWidth(), descentY, descentLinePaint); // ButtomLine描畫 Paint bottomLinePaint = new Paint( Paint.ANTI_ALIAS_FLAG); bottomLinePaint.setColor( Color.MAGENTA); canvas.drawLine(0, bottomY, getWidth(), bottomY, bottomLinePaint); 

希望本文所述對大家Android程式設計有所協助。