WuziqiPanel.java

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

/**
 * 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();

    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);
    }

    @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);

        mPanelWidth=w;
        mLineHeight=mPanelWidth*1.0f/MAX_LINE;

    }

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

    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);


        }

    }
}