转盘旋转兼拖动

package com.example.administrator.jlj20180412demo.newview;

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

import java.util.Timer;
import java.util.TimerTask;

/**
 * Created by Administrator on 2018/4/12.
 */

public class MyView extends View{

    private Paint paint;
    private int[] col;
    private int w;
    private int h;
    private RectF rectF;
    private float firstX;
    float z = -400;
    float s = -400;
    float y = 400;
    float x = 400;



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

    public MyView(Context context, @Nullable AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public MyView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        //实例化一个画笔
        paint = new Paint();
        //给画笔上颜色
        paint.setColor(Color.RED);
        /**
         * 可以弄个色盘，使用for循环给画笔上颜色
         */
        col = new int[]{Color.LTGRAY, Color.BLUE, Color.RED, Color.GREEN, Color.MAGENTA, Color.WHITE};

        //矩形
        rectF = new RectF(z, s, y, x);
    }

    /**
     * 取到宽高，点一个自定义view的中心点
     *
     * @param widthMeasureSpec
     * @param heightMeasureSpec
     */

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        int width = getMeasuredWidth();
        int height = getMeasuredHeight();
        w = width / 2;
        h = height / 2;
    }

    /**
     * 搞起来，画
     *
     * @param canvas
     */
    int d = 60;

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        canvas.translate(w, h);//把当前画布的原点移到       位置变换
        canvas.rotate(d);//旋转角度，用于控制角度位置
        drawCircleWithColor(canvas);//用色彩画圆
    }

    int starteangle = 0;

    private void drawCircleWithColor(Canvas canvas) {
        for (int i = 0; i < col.length; i++) {
            paint.setColor(col[i]);
            canvas.drawArc(rectF, starteangle, 360 / col.length, true, paint);
            starteangle += 360 / col.length;
        }
    }


        @Override
        public boolean onTouchEvent(MotionEvent event) {
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN://按下
                float lastX;
                firstX = lastX = event.getX();
                break;
            case MotionEvent.ACTION_MOVE://移动
                w = (int) event.getX();
                h = (int) event.getY();
                invalidate();
                break;
            case MotionEvent.ACTION_UP:// 抬起
                lastX = event.getX();
                if (lastX - firstX == 0) {
                    Timer timer = new Timer();
                    TimerTask timerTask = new TimerTask() {
                        @Override
                        public void run() {
                            d += 1;
                            postInvalidate();
                        }
                    };
                    timer.schedule(timerTask, 0, 1);
                } else {
                    //发生了拖拽
                }
                break;
        }
        return true;
    }

}