SurfaceView的基本用法模板自定义实现抽奖盘

一概述
SurfaceView是在子线程中进行绘制的，SurfaceHolder提供Canvas并管理SurfaceView的生命周期。

二、模板编程思路
1、继承SurfaceView,声明一个绘制的线程，获取SurfaceHolder，控制线程的变量，Canvas。
2、构造方法中对变量进行初始化，SurfaceHolder提供Canvas与生命周期的CallBack;
3、在surfaceCreated方法中启动线程绘制
4、surfaceDestroyed方法中停止线程

1、SurfaceViewTempLate类

package template;


import android.content.Context;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

public class SurfaceViewTempLate extends SurfaceView implements SurfaceHolder.Callback,Runnable {

    private SurfaceHolder holder;
    private Canvas  mCanvas;
    //用于绘制的线程
    private  Thread t;
    //线程控制开关
    private boolean isRunning = false;
    public SurfaceViewTempLate(Context context) {
       this(context,null);
    }

    public SurfaceViewTempLate(Context context, AttributeSet attrs) {
        super(context, attrs);
        holder = getHolder();
        holder.addCallback(this);
        //设置可获得焦点
        setFocusable(true);
        setFocusableInTouchMode(true);
        //设置常量
        setKeepScreenOn(true);

    }


    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        isRunning = true;
        t = new Thread(this);
        t.start();

    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
      isRunning = false;
    }

    @Override
    public void run() {

        //不断进行绘制...
         while(isRunning)
         {
              draw();
         }
    }

    private void draw() {

        try {
            mCanvas = holder.lockCanvas();
            if (mCanvas != null)
            {

            }
        }catch (Exception e)
        {

        }finally {

            if (mCanvas != null)
            {
                 holder.unlockCanvasAndPost(mCanvas);
            }
        }


    }
}

三、PackPan的实现
编码思路：
1、拷贝模板SurfaceViewTempLate类修改下名字
2、声明变量
3、重写下onMeasure方法，并初始化布局大小
4、surfaceCreated类中初始化变量
5、在线程中进行绘制背景，盘块，文字，图片

2、LankPan类

package app.kuxiao.com.demo.lack;


import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.Rect;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.util.Log;
import android.util.TypedValue;
import android.view.SurfaceHolder;
import android.view.SurfaceView;



public class LackPan extends SurfaceView implements SurfaceHolder.Callback, Runnable {

    private SurfaceHolder holder;
    private Canvas mCanvas;
    //用于绘制的线程
    private Thread t;
    //线程控制开关
    private boolean isRunning = false;
    //盘块的图片
    private int[] lack_icons = new int[]{R.drawable.danfan, R.drawable.f015, R.drawable.ipad, R.drawable.f040, R.drawable.iphone, R.drawable.meizi};
    //盘块的文字
    private String[] lack_text = new String[]{"单反", "恭喜发财", "Ipad", "恭喜发财", "iPhone", "服装一套"};

    private int[] lack_color = new int[]{0xffffc300, 0xfff17e01, 0xffffc300, 0xfff17e01, 0xffffc300, 0xfff17e01};
    //盘块的数量
    private int lack_count = 6;

    private Bitmap[] lack_bitmap = null;
    //范围
    private RectF mRange = null;
    //整个盘块的直径
    private int mRadius = 0;
    //盘状的画笔
    private Paint mPanPaint;
    //文字的画笔
    private Paint mTextPaint;
    //旋转的速度
    private double mSpeed = 0;
    //开始的角度
    private volatile int mStartAngle = 0;
    //是否点击停止
    private boolean isOnClickStop = false;
    //转盘的中心
    private int mCentre = 0;
    //
    private int mPadding;
    //转盘的背景图
    private Bitmap bg_bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.bg2);
    //设置文字的大小
    private float mTextSize = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, 20, getResources().getDisplayMetrics());

    public LackPan(Context context) {
        this(context, null);
    }

    public LackPan(Context context, AttributeSet attrs) {
        super(context, attrs);
        holder = getHolder();
        holder.addCallback(this);
        //设置可获得焦点
        setFocusable(true);
        setFocusableInTouchMode(true);
        //设置常量
        setKeepScreenOn(true);

    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        //获取控件的高度与宽度之间的最小值
        int width = Math.min(getMeasuredWidth(), getMeasuredHeight());
        //以左边距为准设置边距
        mPadding = getPaddingLeft();
        //设置直径
        mRadius = width - 2 * mPadding;
        //设置中心点
        mCentre = width / 2;
        //设置下View的尺寸
        setMeasuredDimension(width, width);

    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        isRunning = true;
        //初始化盘的画笔
        mPanPaint = new Paint();
        //设置普通显示
        mPanPaint.setAntiAlias(true);
        //设置高频
        mPanPaint.setDither(true);
        //初始化文字画笔
        mTextPaint = new Paint();
        mTextPaint.setTextSize(mTextSize);
        mTextPaint.setColor(0xffffffff);

        //初始化绘制的范围
        mRange = new RectF(mPadding, mPadding, mPadding + mRadius, mPadding + mRadius);
        //初始化图片
        lack_bitmap = new Bitmap[lack_count];
        for (int i = 0; i < lack_count; i++) {
            lack_bitmap[i] = BitmapFactory.decodeResource(getResources(), lack_icons[i]);
        }

        t = new Thread(this);
        t.start();

    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

    }


    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        isRunning = false;
    }

    @Override
    public void run() {

        //不断进行绘制...
        while (isRunning) {
            long start = System.currentTimeMillis();
            draw();
            long end = System.currentTimeMillis();
            //强制绘制的时间为50毫秒以上
            if (end - start <= 50) {
                try {
                    Thread.sleep(50 - (end - start));
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    private void draw() {

        try {
            mCanvas = holder.lockCanvas();
            if (mCanvas != null) {
                //绘制背景
                drawBg();
                //绘制盘块
                drawPan();

            }
        } catch (Exception e) {

        } finally {

            if (mCanvas != null) {
                holder.unlockCanvasAndPost(mCanvas);
            }
        }


    }

    private void drawPan() {

        float startAngle = mStartAngle;
        float sweedAngle = 360 / lack_count;

        for (int i = 0; i < lack_count; i++) {

            mPanPaint.setColor(lack_color[i]);
            //绘制背景扇形
            mCanvas.drawArc(mRange, startAngle, sweedAngle, true, mPanPaint);
            //绘制文字
            drawText(startAngle, sweedAngle, lack_text[i]);
            //绘制图片
            drawIcon(startAngle, lack_bitmap[i]);

            startAngle += sweedAngle;
        }
        mStartAngle += mSpeed;
        if (isOnClickStop) {
            mSpeed--;
            if (mSpeed < 0) {
                mSpeed = 0;
                isOnClickStop = false;
            }

        }

    }

    /**
     * 绘制图标
     *
     * @param startAngle
     * @param bitmap
     */
    private void drawIcon(float startAngle, Bitmap bitmap) {

        //图片的宽度
        int icon_width = mRadius / 8;

        float angle = (float) ((startAngle + 360 / lack_count / 2) * Math.PI / 180);
        //极坐标换算公式 x = RCOSα
        //             y = RSinα 求得图片的中心位置
        int x = (int) (mCentre + mRadius / 4 * Math.cos(angle));
        int y = (int) (mCentre + mRadius / 4 * Math.sin(angle));
        //设置图片的范围
        Rect rect = new Rect(x - icon_width / 2, y - icon_width / 2, x + icon_width / 2, y + icon_width / 2);
        mCanvas.drawBitmap(bitmap, null, rect, null);

    }

    /**
     * 绘制文字
     *
     * @param startAngle
     * @param sweedAngle
     * @param s
     */
    private void drawText(float startAngle, float sweedAngle, String s) {

        Path path = new Path();
        path.addArc(mRange, startAngle, sweedAngle);
        //获取文字的长度
        float textwidth = mTextPaint.measureText(s);
        float hOffset = (float) (sweedAngle * Math.PI / 180 / 4 * mRadius - textwidth / 2);
        float vOffset = mRadius / 2 / 4;
        mCanvas.drawTextOnPath(s, path, hOffset, vOffset, mTextPaint);

    }

    /**
     * 绘制背景
     */
    private void drawBg() {

        mCanvas.drawColor(0xffffffff);
        mCanvas.drawBitmap(bg_bitmap, null, new RectF(mPadding / 2, mPadding / 2,
                getMeasuredHeight() - mPadding / 2, getMeasuredHeight() - mPadding / 2), null);

    }

    /**
     * 开始转动
     * @param mSpeed
     */
    public void start(int mSpeed,int index) {

        this.mSpeed = mSpeed;
        float angle = 360/lack_count;
        //当前项的中奖范围
        //0的话 正中奖是旋转240度，可以偏差30度 所以为 210-270
        //1的话 正中奖是旋转180,180-30~180+30 （150-210）
        //2
        float start = 270 - (index + 1 )* angle + 360*3;//转4圈
        float end = start + angle;

        double mSpeed1 = (-1 +(Math.sqrt(1+4*2*start)))/2;
        double mSpeed2 = (-1 +(Math.sqrt(1+4*2*end)))/2;
        Log.i("LackPan","mSpeed1的值为" + mSpeed1);
        Log.i("LackPan","mSpeed2的值为" + mSpeed2);
        //设置速度为mSpeed1~mSpeed2中的一个随机数
        this.mSpeed = mSpeed1;
        //重新设置开始角度为0；

    }

    /**
     * 停止转动
     */
    public void stop() {
        mStartAngle = 0;
        isOnClickStop = true;
       /* final Timer timer = new Timer();
        timer.schedule(new TimerTask() {

            @Override
            public void run() {
                mSpeed--;
                Log.i("LackPan", "mSpeed的值为" + mSpeed);
                if (mSpeed <= 0) {
                    mSpeed = 0;
                    timer.cancel();

                }
            }
        }, 0, 20);*/
    }

}

2、MainActivity类

package app.kuxiao.com.demo.lack;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;


public class MainActivity extends AppCompatActivity {

    private LackPan mLackPan = null;
    private ImageView mImageView = null;
    private  boolean isOnclickStart = false;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.content_main);
        mLackPan = (LackPan) findViewById(R.id.lackPan);
        mImageView = (ImageView) findViewById(R.id.image_start);
        mImageView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                  if (isOnclickStart)
                  {
                       mLackPan.stop();
                      isOnclickStart = false;
                      mImageView.setImageResource(R.drawable.start);
                  }else
                  {
                      isOnclickStart = true;
                      mImageView.setImageResource(R.drawable.stop);
                      mLackPan.start(50,0);

                  }
            }
        });
    }
}

通过改变每一次绘制的初始角度，让转盘运动。