自定义控件之圆形颜色渐变进度条--SweepGradient

前几天在群里面有人找圆形可颜色渐变进度条，其中主要的知识点是SweepGradient；

 mSweepGradient = new SweepGradient(240, 360, new int[] {　　Color.CYAN,　　Color.DKGRAY,　　Color.GRAY,　　Color.LTGRAY,　　Color.MAGENTA,
　　Color.GREEN,　　Color.TRANSPARENT, 　　Color.BLUE },　　 null); 

如上：第三个参数为渐变颜色内容，前两个是坐标信息，240：渲染中心点x 坐标；360：渲染中心y 点坐标。

先绘制圆形：

package com.soyoungboy.sweepgradientprogress;

import android.content.Context;
import android.graphics.BlurMaskFilter;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.EmbossMaskFilter;
import android.graphics.Paint;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.view.View;
/**
 * 圆形颜色渐变的进度条
 * @author soyoungboy
 *
 */
public class SweepGradientCircleProgressBar extends View {
    private Paint pathPaint;
    private Paint fillArcPaint;
    // 设置光源的方向
    private float[] direction = new float[] {1, 1, 1};

    // 设置环境光亮度
    private float light = 0.4f;

    // 选择要应用的反射等级
    private float specular = 6;
    private EmbossMaskFilter emboss;
    private RectF oval ;
    private BlurMaskFilter mBlur;
    // view重绘的标记
    private boolean reset = false;
    // 向 mask应用一定级别的模糊
    private float blur = 3.5f;
    private int arcradus = 30;
    public SweepGradientCircleProgressBar(Context context ,AttributeSet attrs) {
        super(context,attrs);
        initPaint();
        oval = new RectF();
        emboss = new EmbossMaskFilter(direction, light, specular, blur);
        mBlur = new BlurMaskFilter(20, BlurMaskFilter.Blur.NORMAL);
    }

    //初始化画笔操作
    private void initPaint() {
        //初始化画笔操作
        pathPaint = new Paint();
        // 设置是否抗锯齿
        pathPaint.setAntiAlias(true);
        // 帮助消除锯齿
        pathPaint.setFlags(Paint.ANTI_ALIAS_FLAG);
        // 设置中空的样式
        pathPaint.setStyle(Paint.Style.STROKE);
        pathPaint.setDither(true);
        pathPaint.setStrokeJoin(Paint.Join.ROUND);

        fillArcPaint = new Paint();
        // 设置是否抗锯齿
        fillArcPaint.setAntiAlias(true);
        // 帮助消除锯齿
        fillArcPaint.setFlags(Paint.ANTI_ALIAS_FLAG);
        // 设置中空的样式
        fillArcPaint.setStyle(Paint.Style.STROKE);
        fillArcPaint.setDither(true);
        fillArcPaint.setStrokeJoin(Paint.Join.ROUND);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        int height = getMeasuredWidth();
        int width = getMeasuredWidth();
        //半径 = 宽/2-圆环的宽度
        int radius = width/2-arcradus;
        int cx = width/2;
        int cy = height/2;
        //绘制画笔颜色
        pathPaint.setColor(Color.RED);
        //画笔的宽度
        pathPaint.setStrokeWidth(10);
        pathPaint.setMaskFilter(emboss);
        canvas.drawCircle(cx, cy, radius, pathPaint);
    }

}

效果如下：