转载自：books1958 原文：/books1958/article/details/48267903
本博文包含两个组件，首先上效果图：
1.ProgressBarView1（支持拖动）：
2.ProgressBarView2（不同进度值显示不同颜色，不支持拖拽）：
代码不多，注释也比较详细，全部贴上了：
（一）ProgressBarView1:
/*** 自定义绚丽的ProgressBar.*/public class ProgressBarView1 extends View {/*** 进度条所占用的角度*/private static final int ARC_FULL_DEGREE = 300;/*** 弧线的宽度*/private int STROKE_WIDTH;/*** 组件的宽，高*/private int width, height;/*** 进度条最大值和当前进度值*/private float max, progress;/*** 是否允许拖动进度条*/private boolean draggingEnabled = false;/*** 绘制弧线的矩形区域*/private RectF circleRectF;/*** 绘制弧线的画笔*/private Paint progressPaint;/*** 绘制文字的画笔*/private Paint textPaint;/*** 绘制当前进度值的画笔*/private Paint thumbPaint;/*** 圆弧的半径*/private int circleRadius;/*** 圆弧圆心位置*/private int centerX, centerY;public ProgressBarView1(Context context) {super(context);init();}public ProgressBarView1(Context context, AttributeSet attrs) {super(context, attrs);init();}public ProgressBarView1(Context context, AttributeSet attrs, int defStyleAttr) {super(context, attrs, defStyleAttr);init();}private void init() {progressPaint = new Paint();progressPaint.setAntiAlias(true);textPaint = new Paint();textPaint.setColor(Color.WHITE);textPaint.setAntiAlias(true);thumbPaint = new Paint();thumbPaint.setAntiAlias(true);//使用自定义字体textPaint.setTypeface(Typeface.createFromAsset(getContext().getAssets(), "fangz.ttf"));}@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {super.onMeasure(widthMeasureSpec, heightMeasureSpec);if (width == 0 || height == 0) {width = getWidth();height = getHeight();//计算圆弧半径和圆心点circleRadius = Math.min(width, height) / 2;STROKE_WIDTH = circleRadius / 12;circleRadius -= STROKE_WIDTH;centerX = width / 2;centerY = height / 2;//圆弧所在矩形区域circleRectF = new RectF();circleRectF.left = centerX - circleRadius;circleRectF.top = centerY - circleRadius;circleRectF.right = centerX + circleRadius;circleRectF.bottom = centerY + circleRadius;}}private Rect textBounds = new Rect();@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);float start = 90 + ((360 - ARC_FULL_DEGREE) >> 1); //进度条起始点float sweep1 = ARC_FULL_DEGREE * (progress / max); //进度划过的角度float sweep2 = ARC_FULL_DEGREE - sweep1; //剩余的角度//绘制起始位置小圆形progressPaint.setColor(Color.WHITE);progressPaint.setStrokeWidth(0);progressPaint.setStyle(Paint.Style.FILL);float radians = (float) (((360.0f - ARC_FULL_DEGREE) / 2) / 180 * Math.PI);float startX = centerX - circleRadius * (float) Math.sin(radians);float startY = centerY + circleRadius * (float) Math.cos(radians);canvas.drawCircle(startX, startY, STROKE_WIDTH / 2, progressPaint);//绘制进度条progressPaint.setStrokeWidth(STROKE_WIDTH);progressPaint.setStyle(Paint.Style.STROKE);//设置空心canvas.drawArc(circleRectF, start, sweep1, false, progressPaint);//绘制进度条背景progressPaint.setColor(Color.parseColor("#d64444"));canvas.drawArc(circleRectF, start + sweep1, sweep2, false, progressPaint);//绘制结束位置小圆形progressPaint.setStrokeWidth(0);progressPaint.setStyle(Paint.Style.FILL);float endX = centerX + circleRadius * (float) Math.sin(radians);float endY = centerY + circleRadius * (float) Math.cos(radians);canvas.drawCircle(endX, endY, STROKE_WIDTH / 2, progressPaint);//上一行文字textPaint.setTextSize(circleRadius >> 1);String text = (int) (100 * progress / max) + "";float textLen = textPaint.measureText(text);//计算文字高度textPaint.getTextBounds("8", 0, 1, textBounds);float h1 = textBounds.height();//% 前面的数字水平居中，适当调整float extra = text.startsWith("1") ? -textPaint.measureText("1") / 2 : 0;canvas.drawText(text, centerX - textLen / 2 + extra, centerY - 30 + h1 / 2, textPaint);//百分号textPaint.setTextSize(circleRadius >> 2);canvas.drawText("%", centerX + textLen / 2 + extra + 5, centerY - 30 + h1 / 2, textPaint);//下一行文字textPaint.setTextSize(circleRadius / 5);text = "可用内存充足";textLen = textPaint.measureText(text);textPaint.getTextBounds(text, 0, text.length(), textBounds);float h2 = textBounds.height();canvas.drawText(text, centerX - textLen / 2, centerY + h1 / 2 + h2, textPaint);//绘制进度位置，也可以直接替换成一张图片float progressRadians = (float) (((360.0f - ARC_FULL_DEGREE) / 2 + sweep1) / 180 * Math.PI);float thumbX = centerX - circleRadius * (float) Math.sin(progressRadians);float thumbY = centerY + circleRadius * (float) Math.cos(progressRadians);thumbPaint.setColor(Color.parseColor("#33d64444"));canvas.drawCircle(thumbX, thumbY, STROKE_WIDTH * 2.0f, thumbPaint);thumbPaint.setColor(Color.parseColor("#99d64444"));canvas.drawCircle(thumbX, thumbY, STROKE_WIDTH * 1.4f, thumbPaint);thumbPaint.setColor(Color.WHITE);canvas.drawCircle(thumbX, thumbY, STROKE_WIDTH * 0.8f, thumbPaint);}private boolean isDragging = false;@Overridepublic boolean onTouchEvent(@NonNull MotionEvent event) {if (!draggingEnabled) {return super.onTouchEvent(event);}//处理拖动事件float currentX = event.getX();float currentY = event.getY();int action = event.getAction();switch (action) {case MotionEvent.ACTION_DOWN://判断是否在进度条thumb位置if (checkOnArc(currentX, currentY)) {float newProgress = calDegreeByPosition(currentX, currentY) / ARC_FULL_DEGREE * max;setProgressSync(newProgress);isDragging = true;}break;case MotionEvent.ACTION_MOVE:if (isDragging) {//判断拖动时是否移出去了if (checkOnArc(currentX, currentY)) {setProgressSync(calDegreeByPosition(currentX, currentY) / ARC_FULL_DEGREE * max);} else {isDragging = false;}}break;case MotionEvent.ACTION_UP:isDragging = false;break;}return true;}private float calDistance(float x1, float y1, float x2, float y2) {return (float) Math.sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2));}/*** 判断该点是否在弧线上（附近）*/private boolean checkOnArc(float currentX, float currentY) {float distance = calDistance(currentX, currentY, centerX, centerY);float degree = calDegreeByPosition(currentX, currentY);return distance > circleRadius - STROKE_WIDTH * 5 && distance < circleRadius + STROKE_WIDTH * 5&& (degree >= -8 && degree <= ARC_FULL_DEGREE + 8);}/*** 根据当前位置，计算出进度条已经转过的角度。*/private float calDegreeByPosition(float currentX, float currentY) {float a1 = (float) (Math.atan(1.0f * (centerX - currentX) / (currentY - centerY)) / Math.PI * 180);if (currentY < centerY) {a1 += 180;} else if (currentY > centerY && currentX > centerX) {a1 += 360;}return a1 - (360 - ARC_FULL_DEGREE) / 2;}public void setMax(int max) {this.max = max;invalidate();}public void setProgress(float progress) {final float validProgress = checkProgress(progress);//动画切换进度值new Thread(new Runnable() {@Overridepublic void run() {float oldProgress = ProgressBarView1.this.progress;for (int i = 1; i <= 100; i++) {ProgressBarView1.this.progress = oldProgress + (validProgress - oldProgress) * (1.0f * i / 100);postInvalidate();SystemClock.sleep(20);}}}).start();}public void setProgressSync(float progress) {this.progress = checkProgress(progress);invalidate();}//保证progress的值位于[0,max]private float checkProgress(float progress) {if (progress < 0) {return 0;}return progress > max ? max : progress;}public void setDraggingEnabled(boolean draggingEnabled) {this.draggingEnabled = draggingEnabled;}}
（二）ProgressBarView2:
/*** 自定义绚丽的ProgressBar.*/public class ProgressBarView2 extends View {/*** 进度条所占用的角度*/private static final int ARC_FULL_DEGREE = 300;//进度条个数private static final int COUNT = 100;//每个进度条所占用角度private static final float ARC_EACH_PROGRESS = ARC_FULL_DEGREE * 1.0f / (COUNT - 1);/*** 弧线细线条的长度*/private int ARC_LINE_LENGTH;/*** 弧线细线条的宽度*/private int ARC_LINE_WIDTH;/*** 组件的宽，高*/private int width, height;/*** 进度条最大值和当前进度值*/private float max, progress;/*** 绘制弧线的画笔*/private Paint progressPaint;/*** 绘制文字的画笔*/private Paint textPaint;/*** 绘制文字背景圆形的画笔*/private Paint textBgPaint;/*** 圆弧的半径*/private int circleRadius;/*** 圆弧圆心位置*/private int centerX, centerY;public ProgressBarView2(Context context) {super(context);init();}public ProgressBarView2(Context context, AttributeSet attrs) {super(context, attrs);init();}public ProgressBarView2(Context context, AttributeSet attrs, int defStyleAttr) {super(context, attrs, defStyleAttr);init();}private void init() {progressPaint = new Paint();progressPaint.setAntiAlias(true);textPaint = new Paint();textPaint.setColor(Color.WHITE);textPaint.setAntiAlias(true);textBgPaint = new Paint();textBgPaint.setAntiAlias(true);}@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {super.onMeasure(widthMeasureSpec, heightMeasureSpec);if (width == 0 || height == 0) {width = getWidth();height = getHeight();//计算圆弧半径和圆心点circleRadius = Math.min(width, height) / 2;ARC_LINE_LENGTH = circleRadius / 6;ARC_LINE_WIDTH = ARC_LINE_LENGTH / 8;centerX = width / 2;centerY = height / 2;}}private Rect textBounds = new Rect();@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);float start = (360 - ARC_FULL_DEGREE) >> 1; //进度条起始角度float sweep1 = ARC_FULL_DEGREE * (progress / max); //进度划过的角度//绘制进度条progressPaint.setColor(Color.parseColor(calColor(progress / max, "#ffff0000", "#ff00ff00")));progressPaint.setStrokeWidth(ARC_LINE_WIDTH);float drawDegree = 1.6f;while (drawDegree <= ARC_FULL_DEGREE) {double a = (start + drawDegree) / 180 * Math.PI;float lineStartX = centerX - circleRadius * (float) Math.sin(a);float lineStartY = centerY + circleRadius * (float) Math.cos(a);float lineStopX = lineStartX + ARC_LINE_LENGTH * (float) Math.sin(a);float lineStopY = lineStartY - ARC_LINE_LENGTH * (float) Math.cos(a);if (drawDegree > sweep1) {//绘制进度条背景progressPaint.setColor(Color.parseColor("#88aaaaaa"));progressPaint.setStrokeWidth(ARC_LINE_WIDTH >> 1);}canvas.drawLine(lineStartX, lineStartY, lineStopX, lineStopY, progressPaint);drawDegree += ARC_EACH_PROGRESS;}//绘制文字背景圆形textBgPaint.setStyle(Paint.Style.FILL);//设置填充textBgPaint.setColor(Color.parseColor("#41668b"));canvas.drawCircle(centerX, centerY, (circleRadius - ARC_LINE_LENGTH) * 0.8f, textBgPaint);textBgPaint.setStyle(Paint.Style.STROKE);//设置空心textBgPaint.setStrokeWidth(2);textBgPaint.setColor(Color.parseColor("#aaaaaaaa"));canvas.drawCircle(centerX, centerY, (circleRadius - ARC_LINE_LENGTH) * 0.8f, textBgPaint);//上一行文字textPaint.setTextSize(circleRadius >> 1);String text = (int) (100 * progress / max) + "";float textLen = textPaint.measureText(text);//计算文字高度textPaint.getTextBounds("8", 0, 1, textBounds);float h1 = textBounds.height();canvas.drawText(text, centerX - textLen / 2, centerY - circleRadius / 10 + h1 / 2, textPaint);//分textPaint.setTextSize(circleRadius >> 3);textPaint.getTextBounds("分", 0, 1, textBounds);float h11 = textBounds.height();canvas.drawText("分", centerX + textLen / 2 + 5, centerY - circleRadius / 10 + h1 / 2 - (h1 - h11), textPaint);//下一行文字textPaint.setTextSize(circleRadius / 6);text = "点击优化";textLen = textPaint.measureText(text);canvas.drawText(text, centerX - textLen / 2, centerY + circleRadius / 2.5f, textPaint);}public void setMax(int max) {this.max = max;invalidate();}//动画切换进度值(异步)public void setProgress(final float progress) {new Thread(new Runnable() {@Overridepublic void run() {float oldProgress = ProgressBarView2.this.progress;for (int i = 1; i <= 100; i++) {ProgressBarView2.this.progress = oldProgress + (progress - oldProgress) * (1.0f * i / 100);postInvalidate();SystemClock.sleep(20);}}}).start();}//直接设置进度值（同步）public void setProgressSync(float progress) {this.progress = progress;invalidate();}/*** 计算渐变效果中间的某个颜色值。* 仅支持 #aarrggbb 模式,例如 #ccc9c9b2*/public String calColor(float fraction, String startValue, String endValue) {int start_a, start_r, start_g, start_b;int end_a, end_r, end_g, end_b;//startstart_a = getIntValue(startValue, 1, 3);start_r = getIntValue(startValue, 3, 5);start_g = getIntValue(startValue, 5, 7);start_b = getIntValue(startValue, 7, 9);//endend_a = getIntValue(endValue, 1, 3);end_r = getIntValue(endValue, 3, 5);end_g = getIntValue(endValue, 5, 7);end_b = getIntValue(endValue, 7, 9);return "#" + getHexString((int) (start_a + fraction * (end_a - start_a)))+ getHexString((int) (start_r + fraction * (end_r - start_r)))+ getHexString((int) (start_g + fraction * (end_g - start_g)))+ getHexString((int) (start_b + fraction * (end_b - start_b)));}//从原始#AARRGGBB颜色值中指定位置截取，并转为int.private int getIntValue(String hexValue, int start, int end) {return Integer.parseInt(hexValue.substring(start, end), 16);}private String getHexString(int value) {String a = Integer.toHexString(value);if (a.length() == 1) {a = "0" + a;}return a;}}
