Android 渐变圆环，圆形进度条效果实现，android系统开发工程师

public CircleProgressBar(Context context, AttributeSet attrs) {

super(context, attrs);

init(attrs, 0);

}

public CircleProgressBar(Context context, AttributeSet attrs, int defStyle) {

super(context, attrs, defStyle);

init(attrs, defStyle);

}

private void init(AttributeSet attrs, int defStyle) {

mFinishWheelPaint = new Paint();

mFinishWheelPaint.setColor(Color.rgb(100, 113, 205));

mFinishWheelPaint.setStyle(Paint.Style.STROKE);// 空心

mFinishWheelPaint.setStrokeCap(Paint.Cap.ROUND);// 圆角画笔

mFinishWheelPaint.setAntiAlias(true);// 去锯齿

mCenterWheelPaint = new Paint();

mCenterWheelPaint.setColor(Color.rgb(243, 243, 243));

mCenterWheelPaint.setStyle(Paint.Style.STROKE);

mCenterWheelPaint.setStrokeCap(Paint.Cap.ROUND);

mCenterWheelPaint.setAntiAlias(true);

mDefaultWheelPaint = new Paint();

mDefaultWheelPaint.setColor(Color.rgb(127, 127, 127));

mDefaultWheelPaint.setStyle(Paint.Style.STROKE);

mDefaultWheelPaint.setStrokeCap(Paint.Cap.ROUND);

mDefaultWheelPaint.setAntiAlias(true);

mTitlePaint = new Paint();

mTitlePaint.setAntiAlias(true);

mTitlePaint.setColor(Color.WHITE);

mStepPaint = new Paint();

mStepPaint.setAntiAlias(true);

mStepPaint.setColor(Color.WHITE);

mTargetPaint = new Paint();

mTargetPaint.setAntiAlias(true);

mTargetPaint.setColor(Color.WHITE);

mAnim = new BarAnimation();

}

@Override

protected void onDraw(Canvas canvas) {

canvas.drawArc(mWheelRect, 0, 359, false, mDefaultWheelPaint);

canvas.drawArc(mWheelRect, 0, 359, false, mCenterWheelPaint);

canvas.drawArc(mWheelRect, 90, mSweepAnglePer, false, mFinishWheelPaint);

// canvas.drawText(“步数”, mWheelRect.centerX() - (mTitlePaint.measureText(“步数”) / 2), mTitleY,

// mTitlePaint);

canvas.drawText(mCurrStepNum + “”,

mWheelRect.centerX() - (mStepPaint.measureText(String.valueOf(mCurrStepNum)) / 2), mStepY,

mStepPaint);

String description = “”;

float percent = getPercent();

if(percent > 0.5){

description =“严重污染”;

}else if(percent<0.5){

description =“中等污染”;

}else{

description =“普通污染”;

}

canvas.drawText(description , mWheelRect.centerX() -

(mTargetPaint.measureText(description) / 2), mTargetY, mTargetPaint);

SweepGradient sweepGradient = new SweepGradient(mWheelRect.centerX(), mWheelRect.centerY(),

new int[]{getResources().getColor(R.color.color_environment_severe), getResources().getColor(R.color.color_environment_serious),

getResources().getColor(R.color.color_environment_excellent),

getResources().getColor(R.color.color_environment_good), getResources().getColor(R.color.color_environment_mild),

getResources().getColor(R.color.color_environment_moderate)}, null);

mFinishWheelPaint.setShader(sweepGradient);

}

@Override

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

int height = getDefaultSize(getSuggestedMinimumHeight(), heightMeasureSpec);

int width = getDefaultSize(getSuggestedMinimumWidth(), widthMeasureSpec);

int min = Math.min(width, height);// 获取View最短边的长度

setMeasuredDimension(min, min);// 强制改View为以最短边为长度的正方形

mCircleStrokeWidth = getTextScale(15, min);// 圆弧的宽度

pressExtraStrokeWidth = getTextScale(10, min);// 圆弧离矩形的距离

mWheelRect.set(mCircleStrokeWidth + pressExtraStrokeWidth, mCircleStrokeWidth + pressExtraStrokeWidth,

min - mCircleStrokeWidth - pressExtraStrokeWidth, min - mCircleStrokeWidth - pressExtraStrokeWidth);// 设置矩形

mTitlePaint.setTextSize(getTextScale(60, min));

mStepPaint.setTextSize(getTextScale(120, min));

mTargetPaint.setTextSize(getTextScale(40, min));

mTitleY = getTextScale(170, min);

mStepY = getTextScale(300, min);

mTargetY = getTextScale(380, min);

mFini

《Android学习笔记总结+最新移动架构视频+大厂安卓面试真题+项目实战源码讲义》

【docs.qq.com/doc/DSkNLaERkbnFoS0ZF】 完整资料开源分享

shWheelPaint.setStrokeWidth(mCircleStrokeWidth);

mCenterWheelPaint.setStrokeWidth(mCircleStrokeWidth);

mDefaultWheelPaint.setStrokeWidth(mCircleStrokeWidth - getTextScale(2, min));

mDefaultWheelPaint.setShadowLayer(getTextScale(10, min), 0, 0, Color.rgb(127, 127, 127));// 设置阴影

}

/**

• 进度条动画

• @author Administrator

*/

public class BarAnimation extends Animation {

/**

• 每次系统调用这个方法时， 改变mSweepAnglePer，mPercent，stepnumbernow的值，

• 然后调用postInvalidate()不停的绘制view。

*/

@Override

protected void applyTransformation(float interpolatedTime, Transformation t) {

// if (interpolatedTime < 1.0f) {

// mPercent = Float.parseFloat(mDecimalFormat.format(interpolatedTime * mStepNum * 100f / mMaxStepNum));// 将浮点值四舍五入保留一位小数

// mSweepAnglePer = interpolatedTime * mStepNum * 360 / mMaxStepNum;

// mCurrStepNum = (int) (interpolatedTime * mStepNum);

// } else {

mPercent = Float.parseFloat(mDecimalFormat.format(mStepNum * 100f / mMaxStepNum));// 将浮点值四舍五入保留一位小数

if (mPercent > 100.0f) {

mPercent = 100.0f;

}

PERCENT = String.valueOf(mPercent);

mSweepAnglePer = mStepNum * 360 / mMaxStepNum;

mCurrStepNum = mStepNum;

// }

requestLayout();

}

}

public float getPercent() {

return mPercent;

}

/**

• 根据控件的大小改变绝对位置的比例

• @param n

• @param m

• @return

*/

public float getTextScale(float n, float m) {

return n / 500 * m;

}

/**

• 更新步数和设置一圈动画时间

• @param stepCount

• @param time

*/

public void update(int stepCount, int time) {

this.mStepNum = stepCount;

mAnim.setDuration(time);

// setAnimationTime(time);

this.startAnimation(mAnim);

}

/**

• @param stepNum

*/

public void setMaxStepNum(int stepNum) {

mMaxStepNum = stepNum;

GOAL_STEP = String.valueOf(mMaxStepNum);

}

public void setColor(int color) {

mFinishWheelPaint.setColor(color);

mStepPaint.setColor(color);

写在最后

由于本文罗列的知识点是根据我自身总结出来的，并且由于本人水平有限，无法全部提及，欢迎大神们能补充~

将来我会对上面的知识点一个一个深入学习，也希望有童鞋跟我一起学习，一起进阶。

提升架构认知不是一蹴而就的，它离不开刻意学习和思考。

**这里，笔者分享一份从架构哲学的层面来剖析的视频及资料分享给大家，**梳理了多年的架构经验，筹备近1个月最新录制的，相信这份视频能给你带来不一样的启发、收获。

最近还在整理并复习一些Android基础知识点，有问题希望大家够指出，谢谢。

希望读到这的您能转发分享和关注一下我，以后还会更新技术干货，谢谢您的支持！

转发+点赞+关注，第一时间获取最新知识点

Android架构师之路很漫长，一起共勉吧！

希望有童鞋跟我一起学习，一起进阶。

提升架构认知不是一蹴而就的，它离不开刻意学习和思考。

**这里，笔者分享一份从架构哲学的层面来剖析的视频及资料分享给大家，**梳理了多年的架构经验，筹备近1个月最新录制的，相信这份视频能给你带来不一样的启发、收获。

[外链图片转存中…(img-SXL4I15H-1640921847421)]

[外链图片转存中…(img-geur0FzR-1640921847422)]

最近还在整理并复习一些Android基础知识点，有问题希望大家够指出，谢谢。

希望读到这的您能转发分享和关注一下我，以后还会更新技术干货，谢谢您的支持！

转发+点赞+关注，第一时间获取最新知识点

Android架构师之路很漫长，一起共勉吧！

本文已被CODING开源项目：《Android学习笔记总结+移动架构视频+大厂面试真题+项目实战源码》收录