Path 的概念：

Path類封裝由直線段，二次曲線和三次曲線組成的復合（多個輪廓）幾何路徑。可以使用canvas.drawPath（path，paint）對其進行填充或描邊繪制（基于Paint的Style），也可以用于剪切或在路徑上繪制文本

Path 的使用也就是上一篇canvas 里面沒有說的drawPath方法

（1）lineTo、rLineTo? 繪制線? (注意很多方法都有不帶r與帶r 我也寫了2邊它們的區別，不帶r的)

（2）moveTo、rMoveTo 修改起始點位置

（3）setLastPoint 修改最后點的位置(假如豎線的長度本想想畫400長度結果為了600的長度，這個時候可以使用該方法修改)

?下面說一些添加圖形的方法在說之前先說下Path.Direction方法

Path.Direction.CW 順時針繪制，Path.Direction.CCW 逆時針繪制 ，了解這個在看下面的常規圖形方法(為了更好的理解可以看案例9 的效果圖以及代碼給出順時針和逆時針的效果圖)

? (4)? addRect 繪制矩形（長方形和正方形）

? (5)? addCircle 繪制圓形

（6）addOval 繪制橢圓

（7）addRoundRect 繪制圓角矩形

（8）addArc 繪制圓弧

（9）drawTextOnPath??設置決定了文本沿著路徑的起始位置

（10）close? 閉合path

（11）setFillType?設置路徑的填充類型

? (12)?quadTo 和cubicTo 貝塞爾曲線 (這個之前項目中寫過水滴的效果等有空在整理下）

1 lineTo、rLineTo? 繪制線? (注意很多方法都有不帶r與帶r 我也寫了2邊它們的區別，不帶r的)

 paint.setAntiAlias(true);// 設置畫筆的style (Paint.Style.FILL填充,Paint.Style.STROKE描邊,Paint.Style.FILL_AND_STROKE填充加描邊  )paint.setStyle(Paint.Style.STROKE);// 設置畫筆的顏色paint.setColor(Color.RED);//設置描邊寬度paint.setStrokeWidth(10f);Path path = new Path();path.lineTo(200, 400);// 繪制線canvas.drawPath(path, paint);

效果圖

在繪制一些折線如下

  paint.setAntiAlias(true);// 設置畫筆的style (Paint.Style.FILL填充,Paint.Style.STROKE描邊,Paint.Style.FILL_AND_STROKE填充加描邊  )paint.setStyle(Paint.Style.STROKE);// 設置畫筆的顏色paint.setColor(Color.RED);//設置描邊寬度paint.setStrokeWidth(10f);Path path = new Path();path.lineTo(200, 400);path.lineTo(300, 100);path.lineTo(400, 400);path.lineTo(500, 50);path.lineTo(600, 400);path.lineTo(700, 100);path.lineTo(800, 400);// 繪制線canvas.drawPath(path, paint);

效果圖如下

2?moveTo、rMoveTo 修改起始點位置(由于lineTo 默認其實點為0.0 如果不想從默認點開始需要借助?moveTo、rMoveTo)

?下面會一條豎線代碼如下

  paint.setAntiAlias(true);// 設置畫筆的style (Paint.Style.FILL填充,Paint.Style.STROKE描邊,Paint.Style.FILL_AND_STROKE填充加描邊  )paint.setStyle(Paint.Style.STROKE);// 設置畫筆的顏色paint.setColor(Color.RED);//設置描邊寬度paint.setStrokeWidth(10f);Path path = new Path();path.moveTo(200,200);path.lineTo(200, 400);// 繪制線canvas.drawPath(path, paint);

效果圖

3?setLastPoint 修改最后點的位置(假如豎線的長度本想想畫400長度結果為了600的長度，這個時候可以使用該方法修改)

     paint.setAntiAlias(true);// 設置畫筆的style (Paint.Style.FILL填充,Paint.Style.STROKE描邊,Paint.Style.FILL_AND_STROKE填充加描邊  )paint.setStyle(Paint.Style.STROKE);// 設置畫筆的顏色paint.setColor(Color.RED);//設置描邊寬度paint.setStrokeWidth(10f);Path path = new Path();path.moveTo(200,200);// 和path.lineTo(200, 400); 長度一樣path.lineTo(200, 600);path.setLastPoint(200,400);

效果圖如下

4? addRect 矩形

 paint.setAntiAlias(true);// 設置畫筆的style (Paint.Style.FILL填充,Paint.Style.STROKE描邊,Paint.Style.FILL_AND_STROKE填充加描邊  )paint.setStyle(Paint.Style.STROKE);// 設置畫筆的顏色paint.setColor(Color.RED);//設置描邊寬度paint.setStrokeWidth(10f);Path path = new Path();// 設置一個矩形path.addRect(100,200, 600, 500,Path.Direction.CW);// 繪制canvas.drawPath(path, paint);

或者

  paint.setAntiAlias(true);// 設置畫筆的style (Paint.Style.FILL填充,Paint.Style.STROKE描邊,Paint.Style.FILL_AND_STROKE填充加描邊  )paint.setStyle(Paint.Style.STROKE);// 設置畫筆的顏色paint.setColor(Color.RED);//設置描邊寬度paint.setStrokeWidth(10f);Path path = new Path();// 設置一個矩形RectF rect = new RectF();rect.left = 100;rect.top = 200;rect.right = 600;rect.bottom = 500;path.addRect(rect,Path.Direction.CW);// 繪制canvas.drawPath(path, paint);

?效果圖如下

5?addCircle 圓形

  paint.setAntiAlias(true);// 設置畫筆的style (Paint.Style.FILL填充,Paint.Style.STROKE描邊,Paint.Style.FILL_AND_STROKE填充加描邊  )paint.setStyle(Paint.Style.STROKE);// 設置畫筆的顏色paint.setColor(Color.RED);//設置描邊寬度paint.setStrokeWidth(10f);Path path = new Path();// 設置一個圓path.addCircle(500, 500, 300, Path.Direction.CW);// 繪制canvas.drawPath(path, paint);

效果圖如下

6?addOval 橢圓

  paint.setAntiAlias(true);// 設置畫筆的style (Paint.Style.FILL填充,Paint.Style.STROKE描邊,Paint.Style.FILL_AND_STROKE填充加描邊  )paint.setStyle(Paint.Style.STROKE);// 設置畫筆的顏色paint.setColor(Color.RED);//設置描邊寬度paint.setStrokeWidth(10f);Path path = new Path();// 設置一個圓path.addOval(100,200, 600, 500,Path.Direction.CW);// 繪制canvas.drawPath(path, paint);

或者

 paint.setAntiAlias(true);// 設置畫筆的style (Paint.Style.FILL填充,Paint.Style.STROKE描邊,Paint.Style.FILL_AND_STROKE填充加描邊  )paint.setStyle(Paint.Style.STROKE);// 設置畫筆的顏色paint.setColor(Color.RED);//設置描邊寬度paint.setStrokeWidth(10f);Path path = new Path();// 設置一個圓RectF rect = new RectF();rect.left = 100;rect.top = 200;rect.right = 600;rect.bottom = 500;path.addRect(rect, Path.Direction.CW);// 繪制canvas.drawPath(path, paint);

效果圖如下

7

 paint.setAntiAlias(true);// 設置畫筆的style (Paint.Style.FILL填充,Paint.Style.STROKE描邊,Paint.Style.FILL_AND_STROKE填充加描邊  )paint.setStyle(Paint.Style.STROKE);// 設置畫筆的顏色paint.setColor(Color.RED);//設置描邊寬度paint.setStrokeWidth(10f);Path path = new Path();path.addRoundRect(100,200,600,500,100,200, Path.Direction.CW);// 繪制canvas.drawPath(path, paint);

?或者

 paint.setAntiAlias(true);// 設置畫筆的style (Paint.Style.FILL填充,Paint.Style.STROKE描邊,Paint.Style.FILL_AND_STROKE填充加描邊  )paint.setStyle(Paint.Style.STROKE);// 設置畫筆的顏色paint.setColor(Color.RED);//設置描邊寬度paint.setStrokeWidth(10f);Path path = new Path();// 設置一個圓RectF rect = new RectF();rect.left = 100;rect.top = 200;rect.right = 600;rect.bottom = 500;path.addRoundRect(rect,100,200, Path.Direction.CW);// 繪制canvas.drawPath(path, paint);

效果圖如下：

8?addArc 繪制圓弧

 paint.setAntiAlias(true);// 設置畫筆的style (Paint.Style.FILL填充,Paint.Style.STROKE描邊,Paint.Style.FILL_AND_STROKE填充加描邊  )paint.setStyle(Paint.Style.STROKE);// 設置畫筆的顏色paint.setColor(Color.RED);//設置描邊寬度paint.setStrokeWidth(10f);Path path = new Path();path.addArc(100,200,600,500,0,270);// 繪制canvas.drawPath(path, paint);

或者

 paint.setAntiAlias(true);// 設置畫筆的style (Paint.Style.FILL填充,Paint.Style.STROKE描邊,Paint.Style.FILL_AND_STROKE填充加描邊  )paint.setStyle(Paint.Style.STROKE);// 設置畫筆的顏色paint.setColor(Color.RED);//設置描邊寬度paint.setStrokeWidth(10f);Path path = new Path();RectF rect = new RectF();rect.left = 100;rect.top = 200;rect.right = 600;rect.bottom = 500;path.addArc(rect, 0, 270);// 繪制canvas.drawPath(path, paint);

效果圖如下：

?

9 drawTextOnPath??設置決定了文本沿著路徑的起始位置

Path.Direction.CW代碼如下

 paint.setAntiAlias(true);// 設置畫筆的style (Paint.Style.FILL填充,Paint.Style.STROKE描邊,Paint.Style.FILL_AND_STROKE填充加描邊  )paint.setStyle(Paint.Style.STROKE);// 設置畫筆的顏色paint.setColor(Color.RED);//設置描邊寬度paint.setTextSize(100);paint.setStrokeWidth(5f);Path path = new Path();path.addCircle(500, 500, 400, Path.Direction.CW);canvas.drawTextOnPath("期待是心痛的根源，心不動，則不痛。", path, 0, 0, paint);// 繪制canvas.drawPath(path, paint);

效果圖如下：

Path.Direction.CCW代碼如下

paint.setAntiAlias(true);// 設置畫筆的style (Paint.Style.FILL填充,Paint.Style.STROKE描邊,Paint.Style.FILL_AND_STROKE填充加描邊  )paint.setStyle(Paint.Style.STROKE);// 設置畫筆的顏色paint.setColor(Color.RED);//設置描邊寬度paint.setTextSize(100);paint.setStrokeWidth(5f);Path path = new Path();path.addCircle(500, 500, 400, Path.Direction.CCW);canvas.drawTextOnPath("期待是心痛的根源，心不動，則不痛。", path, 0, 0, paint);// 繪制canvas.drawPath(path, paint);

效果圖如下

下面在繪制一個正方形的

 paint.setAntiAlias(true);// 設置畫筆的style (Paint.Style.FILL填充,Paint.Style.STROKE描邊,Paint.Style.FILL_AND_STROKE填充加描邊  )paint.setStyle(Paint.Style.STROKE);// 設置畫筆的顏色paint.setColor(Color.RED);//設置描邊寬度paint.setTextSize(100);paint.setStrokeWidth(5f);Path path = new Path();RectF rect = new RectF();rect.left = 100;rect.top = 200;rect.right = 600;rect.bottom = 500;path.addRect(rect, Path.Direction.CW);canvas.drawTextOnPath("期待是心痛的根源，心不動，則不痛。", path, 0, 0, paint);// 繪制canvas.drawPath(path, paint);

效果圖如下：

10 close 閉合

?現在畫一個豎線和橫線如下

  paint.setAntiAlias(true);// 設置畫筆的style (Paint.Style.FILL填充,Paint.Style.STROKE描邊,Paint.Style.FILL_AND_STROKE填充加描邊  )paint.setStyle(Paint.Style.STROKE);// 設置畫筆的顏色paint.setColor(Color.RED);//設置描邊寬度paint.setTextSize(100);paint.setStrokeWidth(5f);Path path = new Path();path.moveTo(300, 300);path.lineTo(300, 700);path.lineTo(700, 700);// 繪制canvas.drawPath(path, paint);

xiaoguo圖如下

使用閉合方法

 paint.setAntiAlias(true);// 設置畫筆的style (Paint.Style.FILL填充,Paint.Style.STROKE描邊,Paint.Style.FILL_AND_STROKE填充加描邊  )paint.setStyle(Paint.Style.STROKE);// 設置畫筆的顏色paint.setColor(Color.RED);//設置描邊寬度paint.setTextSize(100);paint.setStrokeWidth(5f);Path path = new Path();path.moveTo(300, 300);path.lineTo(300, 700);path.lineTo(700, 700);path.close();// 繪制canvas.drawPath(path, paint);

效果圖如下：

11?setFillType?設置路徑的填充類型， (下面的基本沒用過簡單的了解下)

里面有四種類型?WINDING，EVEN_ODD，INVERSE_WINDING，INVERSE_EVEN_ODD

WINDING 是默認類型，指定“內部”由有符號邊交叉的非零和計算

EVEN_ODD?指定“內部”由奇數個邊交叉計算 ，---個人理解就是交叉本分

INVERSE_WINDING 與{@link#WINDING}相同，但繪制在路徑外部，而不是內部，---個人理解就是繪制畫圖之外的區域

INVERSE_EVEN_ODD 與{@link#偶數奇數}相同，但繪制在路徑外部，而不是內部--個人理解就是交叉也之外的區域

下面畫2個有交叉的圓看看效果

11.1?WINDING (默認部分)

 paint.setAntiAlias(true);// 設置畫筆的style (Paint.Style.FILL填充,Paint.Style.STROKE描邊,Paint.Style.FILL_AND_STROKE填充加描邊  )paint.setStyle(Paint.Style.STROKE);// 設置畫筆的顏色paint.setColor(Color.RED);//設置描邊寬度paint.setTextSize(100);paint.setStrokeWidth(5f);Path path = new Path();path.addCircle(500, 500, 300, Path.Direction.CW);path.addCircle(700, 700, 300, Path.Direction.CW);path.setFillType(Path.FillType.WINDING);// 繪制canvas.drawPath(path, paint);

效果圖如下(感覺和不添加效果一樣)

11.2?INVERSE_WINDING?

 paint.setAntiAlias(true);// 設置畫筆的style (Paint.Style.FILL填充,Paint.Style.STROKE描邊,Paint.Style.FILL_AND_STROKE填充加描邊  )paint.setStyle(Paint.Style.FILL);// 設置畫筆的顏色paint.setColor(Color.RED);//設置描邊寬度paint.setTextSize(100);paint.setStrokeWidth(5f);Path path = new Path();path.addCircle(500, 500, 300, Path.Direction.CW);path.addCircle(700, 700, 300, Path.Direction.CW);path.setFillType(Path.FillType.WINDING);// 繪制canvas.drawPath(path, paint);

效果圖如下：

?

11.3?INVERSE_WINDING

  paint.setAntiAlias(true);// 設置畫筆的style (Paint.Style.FILL填充,Paint.Style.STROKE描邊,Paint.Style.FILL_AND_STROKE填充加描邊  )paint.setStyle(Paint.Style.FILL);// 設置畫筆的顏色paint.setColor(Color.RED);//設置描邊寬度paint.setTextSize(100);paint.setStrokeWidth(5f);Path path = new Path();path.addCircle(500, 500, 300, Path.Direction.CW);path.addCircle(700, 700, 300, Path.Direction.CW);path.setFillType(Path.FillType.INVERSE_WINDING);// 繪制canvas.drawPath(path, paint);

效果圖如下：

11.4 INVERSE_EVEN_ODD

    paint.setAntiAlias(true);// 設置畫筆的style (Paint.Style.FILL填充,Paint.Style.STROKE描邊,Paint.Style.FILL_AND_STROKE填充加描邊  )paint.setStyle(Paint.Style.FILL);// 設置畫筆的顏色paint.setColor(Color.RED);//設置描邊寬度paint.setTextSize(100);paint.setStrokeWidth(5f);Path path = new Path();path.addCircle(500, 500, 300, Path.Direction.CW);path.addCircle(700, 700, 300, Path.Direction.CW);path.setFillType(Path.FillType.INVERSE_EVEN_ODD);// 繪制canvas.drawPath(path, paint);

效果圖如下：

總結

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