Android怎么实现手写板功能

今天小编给大家分享一下Android怎么实现手写板功能的相关知识点，内容详细，逻辑清晰，相信大部分人都还太了解这方面的知识，所以分享这篇文章给大家参考一下，希望大家阅读完这篇文章后有所收获，下面我们一起来了解一下吧。

具体代码如下:

package com.kyli.base.view;import android.content.Context;import android.graphics.Bitmap;import android.graphics.canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.Path;import android.util.AttributeSet;import android.view.MotionEvent;import android.view.View;import androidx.annotation.Nullable;import java.util.ArrayList;import java.util.List;public class SignBoradView extends View {        private int beierThreshold = 4;    private float x = 0;    private float y = 0;        private Paint mPaint;        private int strokeWidth = 10;        private int color = Color.BLACK;        private Path path;    private int state = State.CLEAR;    private interface State {                int START = 0;                int STOP = 1;                int CLEAR = 2;    }    private List<EveryPenPath> everyPenPaths = new ArrayList<>();        private static class EveryPenPath {        public Path path;    }    public SignBoradView(Context context) {        super(context);    }    public SignBoradView(Context context, @Nullable AttributeSet attrs) {        super(context, attrs);    }    public SignBoradView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);    }    private void initPaint() {        if (mPaint == null) {            mPaint = new Paint();            mPaint.setStrokeWidth(strokeWidth);            mPaint.setColor(color);            mPaint.setStyle(Paint.Style.STROKE);            mPaint.setAntiAlias(true);            mPaint.setFlags(Paint.ANTI_ALIAS_FLAG);        }    }    public void start() {        state = State.START;        initPaint();    }        public void stop() {        state = State.STOP;    }        public void clear() {        state = State.CLEAR;        for (int i = everyPenPaths.size() - 1; i >= 0; i--) {            EveryPenPath everyPenPath = everyPenPaths.get(i);            everyPenPath.path.reset();            everyPenPath.path.close();            everyPenPath.path = null;        }        everyPenPaths.clear();        invalidate();    }    public void back() {        int count = everyPenPaths.size();        if (count < 1)            return;        EveryPenPath everyPenPath = everyPenPaths.get(count - 1);        everyPenPath.path.reset();        everyPenPath.path.close();        everyPenPath.path = null;        everyPenPaths.remove(count - 1);        invalidate();    }    @Override    protected void onDraw(Canvas canvas) {        super.onDraw(canvas);        if (state == State.START) {                        for (EveryPenPath e : everyPenPaths) {                canvas.drawPath(e.path, mPaint);            }            //当前进行中的  path!=null            if (path != null) {                canvas.drawPath(path, mPaint);            }        }    }    @Override    public boolean onTouchEvent(MotionEvent event) {        if (state == State.START) {            if (event.getAction() == MotionEvent.ACTION_UP) {                actionUp(event);                invalidate();                return true;            }            if (event.getAction() == MotionEvent.ACTION_MOVE) {                actionMove(event);                invalidate();                return true;            }            if (event.getAction() == MotionEvent.ACTION_DOWN) {                actionDown(event);                invalidate();                return true;            }        }        return super.onTouchEvent(event);    }    private void actionUp(MotionEvent event) {        actionMove(event);                EveryPenPath everyPenPath = new EveryPenPath();        everyPenPath.path = path;        everyPenPaths.add(everyPenPath);        //将当前画笔置位null;        path = null;    }        private void actionMove(MotionEvent event) {                float cX = event.getX();        float cY = event.getY();        float dX = Math.abs(cX - x);//变化量        float dY = Math.abs(cY - y);        if (dX >= beierThreshold || dY >= beierThreshold) {            float rX = x + (cX - x) / 2;            float rY = y + (cY - y) / 2;            path.quadTo(rX, rY, cX, cY);            //下次的x 域y 将重新计算            x = cX;            y = cY;        }    }        private void actionDown(MotionEvent event) {        path = new Path();        x = event.getX();        y = event.getY();        path.moveTo(x, y);    }    public void setBeierThreshold(int beierThreshold) {        this.beierThreshold = beierThreshold;    }    public void setStrokeWidth(int strokeWidth) {        this.strokeWidth = strokeWidth;    }    public void setColor(int color) {        this.color = color;    }    public Bitmap getResult(int bGColor) {        if (everyPenPaths.size() == 0)            return null;        Bitmap bitmap = Bitmap.createBitmap(getWidth(), getHeight(), Bitmap.Config.ARGB_8888);        Canvas canvas = new Canvas(bitmap);        canvas.drawColor(bgColor);        for (int i = 0; i < everyPenPaths.size(); i++) {            if (mPaint == null) {                initPaint();            }            canvas.drawPath(everyPenPaths.get(i).path, mPaint);        }        return bitmap;    }    public Bitmap getResult() {        return getResult(Color.WHITE);    }}

以上就是“Android怎么实现手写板功能”这篇文章的所有内容，感谢各位的阅读！相信大家阅读完这篇文章都有很大的收获，小编每天都会为大家更新不同的知识，如果还想学习更多的知识，请关注编程网精选频道。