增加的代码

 @Override
    protected void onDraw(Canvas canvas) {
         ...
        drawPiece(canvas);
    }

 private void drawPiece(Canvas canvas) {
        for(int i=0,n=mWhiteArray.size();i<n;i++){
            Point whitePoint=mWhiteArray.get(i);
            canvas.drawBitmap(mWhitePiece,
                    (whitePoint.x+(1-ratioPieceOfLineHeigh)/2)*mLineHeight,
                    (whitePoint.y+(1-ratioPieceOfLineHeigh)/2)*mLineHeight,null);
        }

        for(int i=0,n=mBlackArray.size();i<n;i++){
            Point blackPiece=mBlackArray.get(i);
            canvas.drawBitmap(mBlackPiece,
                    (blackPiece.x+(1-ratioPieceOfLineHeigh)/2)*mLineHeight,
                    (blackPiece.y+(1-ratioPieceOfLineHeigh)/2)*mLineHeight,null);
        }

    }

完整代码

package myapplication4.xt.com.wuziqidemo;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Point;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;

import java.util.ArrayList;
import java.util.List;

/**
 * Created by TONG on 2017/6/7.
 */

public class WuziqiPanel extends View {

    //棋盘宽度
    private int mPanelWidth;

    //每格行高
    private float mLineHeight;

    //格子数
    private int MAX_LINE=10;

    private Paint mPaint=new Paint();

    private Bitmap mWhitePiece;

    private  Bitmap mBlackPiece;

    //棋子的大小比例
    private float ratioPieceOfLineHeigh=3*1.0f/4;

    //白棋先走，当前轮到白棋
    private boolean mIsWhite=true;
    private List<Point> mWhiteArray=new ArrayList<>();
    private List<Point> mBlackArray=new ArrayList<>();



    public WuziqiPanel(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);

        setBackgroundColor(0x44ff0000);

        //初始化
        init();

    }

    private void init() {
        mPaint.setColor(0x88000000);
        //抗锯齿
        mPaint.setAntiAlias(true);
        //防抖动
        mPaint.setDither(true);
        //画笔为空心
        mPaint.setStyle(Paint.Style.STROKE);

        mWhitePiece= BitmapFactory.decodeResource(getResources(),R.drawable.stone_w2);
        mBlackPiece=BitmapFactory.decodeResource(getResources(),R.drawable.stone_b1);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int widthSize=MeasureSpec.getSize(widthMeasureSpec);
        int widthMode=MeasureSpec.getMode(widthMeasureSpec);

        int heightSize=MeasureSpec.getSize(heightMeasureSpec);
        int heightMode=MeasureSpec.getMode(heightMeasureSpec);

        int width=Math.min(widthSize,heightSize);

        //嵌套在scrollow中宽度或高度不确定
        if(widthMode==MeasureSpec.UNSPECIFIED){
            width=heightSize;
        }else if(heightMode==MeasureSpec.UNSPECIFIED){
            width=widthSize;
        }

        setMeasuredDimension(width,width);

    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);

        //设置棋盘宽度
        mPanelWidth=w;
        //设置格子线的高度
        mLineHeight=mPanelWidth*1.0f/MAX_LINE;

        //棋子宽度
        int pieceWidth= (int) (mLineHeight*ratioPieceOfLineHeigh);
        mWhitePiece=Bitmap.createScaledBitmap(mWhitePiece,pieceWidth,pieceWidth,false);
        mBlackPiece=Bitmap.createScaledBitmap(mBlackPiece,pieceWidth,pieceWidth, false);

    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {

        int action = event.getAction();
        //不能ACTION_DOWN 因为如果棋盘是可滚动的 在滚动过程中也会执行此事件
        if(action==MotionEvent.ACTION_UP){

            int x= (int) event.getX();
            int y= (int) event.getY();


            Point p=getValidPoint(x,y);

            if(mWhiteArray.contains(p)||mBlackArray.contains(p)){
                return false;
            }

            if(mIsWhite){
                mWhiteArray.add(p);
            }else {
                mBlackArray.add(p);
            }

            invalidate();
            mIsWhite=!mIsWhite;

            return true;
        }
        return true;
    }

    /**
     * 获取点击在合理范围的点
     * @param x
     * @param y
     * @return
     */
    private Point getValidPoint(int x, int y) {
        return new Point((int)(x/mLineHeight),(int)(y/mLineHeight));
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        drawBoard(canvas);

        drawPiece(canvas);
    }

    private void drawPiece(Canvas canvas) {
        for(int i=0,n=mWhiteArray.size();i<n;i++){
            Point whitePoint=mWhiteArray.get(i);
            canvas.drawBitmap(mWhitePiece,
                    (whitePoint.x+(1-ratioPieceOfLineHeigh)/2)*mLineHeight,
                    (whitePoint.y+(1-ratioPieceOfLineHeigh)/2)*mLineHeight,null);
        }

        for(int i=0,n=mBlackArray.size();i<n;i++){
            Point blackPiece=mBlackArray.get(i);
            canvas.drawBitmap(mBlackPiece,
                    (blackPiece.x+(1-ratioPieceOfLineHeigh)/2)*mLineHeight,
                    (blackPiece.y+(1-ratioPieceOfLineHeigh)/2)*mLineHeight,null);
        }

    }

    private void drawBoard(Canvas canvas) {
        int w=mPanelWidth;
        float lineHeight=mLineHeight;

        for(int i=0;i<MAX_LINE;i++){
            int startX= (int) (lineHeight/2);
            int endX= (int) (w-lineHeight/2);

            int y= (int) ((0.5+i)*lineHeight);

            //画竖线
            canvas.drawLine(startX,y,endX,y,mPaint);
            //画横线
            canvas.drawLine(y,startX,y,endX,mPaint);


        }

    }
}

Paste_Image.png