android 画线

Java code ?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 class CustomView1 extends View{ private Paint paint; private ArrayList graphics = new ArrayList(); private Paint lPaint; private Path mPath; private int of = 0 ; private Boolean over = false ; private float mX, mY; private static final float TOUCH_TOLERANCE = 4 ; public CustomView1(Context context) { super (context); paint = new Paint(Paint.ANTI_ALIAS_FLAG); paint.setColor(Color.RED); paint.setStrokeJoin(Paint.Join.ROUND); paint.setStrokeCap(Paint.Cap.ROUND); paint.setStrokeWidth( 65 ); lPaint = new Paint(Paint.ANTI_ALIAS_FLAG); lPaint.setColor(Color.BLACK); lPaint.setStyle(Paint.Style.STROKE); //空心 lPaint.setStrokeJoin(Paint.Join.ROUND); lPaint.setStrokeCap(Paint.Cap.ROUND); lPaint.setStrokeWidth( 5 ); mPath = new Path(); } @Override public boolean onTouchEvent(MotionEvent event) { float x = event.getX(); float y = event.getY(); switch (event.getAction()) { case MotionEvent.ACTION_DOWN: over = false ; graphics.clear(); of= 0 ; graphics.add( new PointF(x, y)); touch_start(x, y); invalidate(); break ; case MotionEvent.ACTION_MOVE: graphics.add( new PointF(x, y)); touch_move(x, y); invalidate(); break ; case MotionEvent.ACTION_UP: over = true ; touch_up(); invalidate(); break ; } return true ; } private void touch_start( float x, float y) { mPath.reset(); mPath.moveTo(x, y); mX = x; mY = y; } private void touch_move( float x, float y) { float dx = Math.abs(x - mX); float dy = Math.abs(y - mY); if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) { mPath.quadTo(mX, mY, (x + mX)/ 2 , (y + mY)/ 2 ); mX = x; mY = y; } } private void touch_up() { mPath.lineTo(mX, mY); } @Override protected void onDraw(Canvas canvas) { // canvas.drawColor(Color.TRANSPARENT,Mode.CLEAR); canvas.drawColor(Color.WHITE); //清理 canvas.drawPath(mPath, lPaint); if (over&&graphics.size()> 0 ){ canvas.drawPoint(graphics.get(of).x, graphics.get(of).y, paint); of+= 1 ; if (of if (of==graphics.size()- 1 ){ mPath.reset(); //移动完成后移除线条 } invalidate(); } } } }

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