涂鸦

来源：互联网发布：手机网络管理软件编辑：程序博客网时间：2024/05/16 23:56

实现功能：导入背景图片，感知用户的touch操作，实现在背景图片上的涂鸦功能。将canvas分为两层，一层时背景图片，一层是用户涂鸦的图片，将两层叠加返回新的view，并存储。

public class HandWriteView extends View{    Paint paint = null;    private Bitmap drawingBitmap = null;     Bitmap afterDrawingBitmap = null;    private Bitmap originalBitmap = null;    private float clickX = 0,clickY = 0;    private float startX = 0,startY = 0;    private boolean isMove = true;    private boolean isClear = false;    public int color = Color.RED;    public float strokeWidth = 6.0f;    public HandWriteView(Context context, Bitmap bitmap)    {        super(context);        drawingBitmap =bitmap;        afterDrawingBitmap = Bitmap.createBitmap(bitmap);    }    public void clear(){        isClear = true;        originalBitmap = Bitmap.createBitmap(drawingBitmap);        invalidate();    }    public void setstyle(float strokeWidth){        this.strokeWidth = strokeWidth;    }    @Override    protected void onDraw(Canvas canvas)    {        super.onDraw(canvas);        canvas.drawBitmap(HandWriting(afterDrawingBitmap), 0, 0,null);    }    public Bitmap HandWriting(Bitmap dwawingBitmap)    {        Canvas canvas = null;        if(isClear){            canvas = new Canvas(originalBitmap);        }        else{            canvas = new Canvas(dwawingBitmap);        }        paint = new Paint();        paint.setStyle(Style.STROKE);        paint.setAntiAlias(true);        paint.setColor(color);        paint.setStrokeWidth(strokeWidth);        if(isMove){            canvas.drawLine(startX, startY, clickX, clickY, paint);        }        startX = clickX;        startY = clickY;        if(isClear){            return originalBitmap;        }        return dwawingBitmap;    }    @Override    public boolean onTouchEvent(MotionEvent event)    {        clickX = event.getX();        clickY = event.getY();        if(event.getAction() == MotionEvent.ACTION_DOWN){            startX=event.getX();            startY=event.getY();            isMove = false;            invalidate();            return true;        }        else if(event.getAction() == MotionEvent.ACTION_MOVE){            isMove = true;            invalidate();            return true;        }        return super.onTouchEvent(event);    }}

注意：在onTouchEvent中必须试试更改clickX和clickY，才能让涂鸦有更好的体验

    clickX = event.getX();        clickY = event.getY();

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