HenCoder Android 開發(fā)進(jìn)階: 自定義 View 1-1 繪制基礎(chǔ)
視頻重點(diǎn)
- 自定義繪制的方式是重寫繪制方法与涡，其中最常用的是 onDraw()
- 繪制的關(guān)鍵是 Canvas 的使用
- Canvas 的繪制類方法： drawXXX() （關(guān)鍵參數(shù)：Paint）
- Canvas 的輔助類方法：范圍裁切和幾何變換
- 可以使用不同的繪制方法來控制遮蓋關(guān)系
自定義繪制知識(shí)的四個(gè)級(jí)別
- Canvas 的 drawXXX() 系列方法及 Paint 最常見的使用
- Paint 的完全攻略
- Canvas 對(duì)繪制的輔助——范圍裁切和幾何變換除师。
- 使用不同的繪制方法來控制繪制順序
draw系列
畫顏色
- canvas.drawColor(Color.parse("#88880000")
- canvas.drawRGB(100, 200, 100);
- canvas.drawARGB(100, 100, 200, 100);
畫圓
- canvas.drawCircle(300, 300, 200, paint);
畫矩形
- canvas.drawRect(float left, float top, float right, float bottom, Paint paint) 畫矩形
- canvas.drawRect(RectF rect, Paint paint)
- canvas.drawRect(Rect rect, Paint paint)
畫點(diǎn)
- cavas.drawPoint(float x, float y, Paint paint)
- cavas.drawPoints(float[] pts, int offset, int count, Paint paint)
- cavas.drawPoints(float[] pts, Paint paint) 畫點(diǎn)（批量）
畫橢圓
- cavas.drawOval(float left, float top, float right, float bottom, Paint paint)
- cavas.drawOval(RectF rect, Paint paint)
畫線
- cavas.drawLine(float startX, float startY, float stopX, float stopY, Paint paint)
- cavas.drawLines(float[] pts, int offset, int count, Paint paint)
- cavas.drawLines(float[] pts, Paint paint) 畫線（批量）
畫圓角矩形
- cavas.drawRoundRect(float left, float top, float right, float bottom, float rx, float ry, Paint paint)
- cavas.drawRoundRect(RectF rect, float rx, float ry, Paint paint)
畫弧形或扇形
- cavas.drawArc(float left, float top, float right, float bottom, float startAngle, float sweepAngle, boolean useCenter, Paint paint)
畫自定義圖形
- cavas.drawPath(Path path, Paint paint)
畫bitmap
- drawBitmap(Bitmap bitmap, float left, float top, Paint paint)
- drawBitmap(Bitmap bitmap, Rect src, RectF dst, Paint paint)
- drawBitmap(Bitmap bitmap, Rect src, Rect dst, Paint paint)
- drawBitmap(Bitmap bitmap, Matrix matrix, Paint paint)
- drawBitmapMesh()
畫文字
- drawText(String text, float x, float y, Paint paint)
Path
- Path 方法第一類：直接描述路徑
- 第一組： addXxx() ——添加子圖形
addCircle(float x, float y, float radius, Direction dir) 添加圓
addOval(float left, float top, float right, float bottom, Direction dir)
addOval(RectF oval, Direction dir)
addRect(float left, float top, float right, float bottom, Direction dir)
addRect(RectF rect, Direction dir)
addRoundRect(RectF rect, float rx, float ry, Direction dir)
addRoundRect(float left, float top, float right, float bottom, float rx, float ry, Direction dir)
addRoundRect(RectF rect, float[] radii, Direction dir)
addRoundRect(float left, float top, float right, float bottom, float[] radii, Direction dir)
addPath(Path path) - 第二組：xxxTo() ——畫線（直線或曲線）
lineTo(float x, float y)
rLineTo(float x, float y)
quadTo(float x1, float y1, float x2, float y2)
rQuadTo(float dx1, float dy1, float dx2, float dy2)
cubicTo(float x1, float y1, float x2, float y2, float x3, float y3)
rCubicTo(float x1, float y1, float x2, float y2, float x3, float y3)
moveTo(float x, float y)
rMoveTo(float x, float y)
arcTo(RectF oval, float startAngle, float sweepAngle, boolean forceMoveTo)
arcTo(float left, float top, float right, float bottom, float startAngle, float sweepAngle, boolean forceMoveTo)
arcTo(RectF oval, float startAngle, float sweepAngle)
addArc(float left, float top, float right, float bottom, float startAngle, float sweepAngle)
addArc(RectF oval, float startAngle, float sweepAngle)
close()
- 第一組： addXxx() ——添加子圖形
- Path 方法第二類：輔助的設(shè)置或計(jì)算
Path.setFillType(Path.FillType ft)
paint系列
- Paint.setColor(int color)
- Paint.setStyle(Paint.Style style)
- FILL 是填充模式（默認(rèn)），
- STROKE 是畫線模式（即勾邊模式），
- FILL_AND_STROKE 是兩種模式一并使用
- Paint.setStrokeWidth(float width)
- Paint.setAntiAlias(boolean aa)
- paint.setStrokeCap(cap)端點(diǎn)形狀
- Paint.setTextSize(float textSize)
