Android自定义圆环倒计时控件

<declare-styleable name="CountDownProgressBar">
  <attr name="countDown_circleWidth" format="dimension" />
  <attr name="countDown_centerTextSize" format="dimension" />
  <attr name="countDown_betaAngle" format="integer" />
  <attr name="countDown_firstColor" format="color" />
  <attr name="countDown_secondColor" format="color" />
  <attr name="countDown_centerTextColor" format="color" />
  <attr name="countDown_isShowGradient" format="boolean" />
</declare-styleable>

import android.animation.ValueAnimator;
import android.content.Context;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.LinearGradient;
import android.graphics.Paint;
import android.graphics.Paint.FontMetricsInt;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.Shader;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.view.View;
import android.view.animation.LinearInterpolator;
 
import com.daodaojk.myapplication.R;
 
public class CountDownProgressBar extends View {
 /**
  * 进度条最大值
  */
 private int maxValue = 200;
 
 /**
  * 当前进度值
  */
 private int currentValue ;
 
 /**
  * 每次扫过的角度，用来设置进度条圆弧所对应的圆心角，alphaAngle=(currentValue/maxValue)*360
  */
 private float alphaAngle;
 
 /**
  * 底部圆弧的颜色，默认为Color.LTGRAY
  */
 private int firstColor;
 
 /**
  * 进度条圆弧块的颜色
  */
 private int secondColor;
 /**
  * 中间文字颜色(默认蓝色)
  */
 private int centerTextColor = Color.BLUE;
 /**
  * 中间文字的字体大小(默认40dp)
  */
 private int centerTextSize;
 
 /**
  * 圆环的宽度
  */
 private int circleWidth;
 
 /**
  * 画圆弧的画笔
  */
 private Paint circlePaint;
 
 /**
  * 画文字的画笔
  */
 private Paint textPaint;
 /**
  * 是否使用渐变色
  */
 private boolean isShowGradient = false;
 
 /**
  * 渐变圆周颜色数组
  */
 private int[] colorArray = new int[]{Color.parseColor("#2773FF"),
   Color.parseColor("#27C0D2"), Color.parseColor("#40C66E")};
 private int duration;
 private OnFinishListener listener;
 private ValueAnimator animator;
 
 public CountDownProgressBar(Context context) {
  this(context, null);
 }
 
 
 public CountDownProgressBar(Context context, AttributeSet attrs) {
  this(context, attrs, 0);
 }
 
 
 public CountDownProgressBar(Context context, AttributeSet attrs, int defStyleAttr) {
  super(context, attrs, defStyleAttr);
 
  TypedArray ta = context.getTheme().obtainStyledAttributes(attrs, R.styleable.CountDownProgressBar,
    defStyleAttr, 0);
  int n = ta.getIndexCount();
 
  for (int i = 0; i < n; i++) {
   int attr = ta.getIndex(i);
   switch (attr) {
    case R.styleable.CountDownProgressBar_countDown_firstColor:
     firstColor = ta.getColor(attr, Color.LTGRAY); // 默认底色为亮灰色
     break;
    case R.styleable.CountDownProgressBar_countDown_secondColor:
     secondColor = ta.getColor(attr, Color.BLUE); // 默认进度条颜色为蓝色
     break;
    case R.styleable.CountDownProgressBar_countDown_centerTextSize:
     centerTextSize = ta.getDimensionPixelSize(attr, (int) dip2px(40)); // 默认中间文字字体大小为40dp
     break;
    case R.styleable.CountDownProgressBar_countDown_circleWidth:
     circleWidth = ta.getDimensionPixelSize(attr, (int) dip2px(6f)); // 默认圆弧宽度为6dp
     break;
    case R.styleable.CountDownProgressBar_countDown_centerTextColor:
     centerTextColor = ta.getColor(attr, Color.BLUE); // 默认中间文字颜色为蓝色
     break;
    case R.styleable.CountDownProgressBar_countDown_isShowGradient:
     isShowGradient = ta.getBoolean(attr, false); // 默认不适用渐变色
     break;
    default:
     break;
   }
  }
  ta.recycle();
 
  circlePaint = new Paint();
  circlePaint.setAntiAlias(true); // 抗锯齿
  circlePaint.setDither(true); // 防抖动
  circlePaint.setStrokeWidth(circleWidth);//画笔宽度
 
  textPaint = new Paint();
  textPaint.setAntiAlias(true);
  textPaint.setDither(true);
 }
 
 @Override
 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
  // 分别获取期望的宽度和高度，并取其中较小的尺寸作为该控件的宽和高,并且不超过屏幕宽高
  int widthPixels = this.getResources().getDisplayMetrics().widthPixels;//获取屏幕宽
  int heightPixels = this.getResources().getDisplayMetrics().heightPixels;//获取屏幕高
  int width = MeasureSpec.getSize(widthMeasureSpec);
  int hedight = MeasureSpec.getSize(heightMeasureSpec);
  int minWidth = Math.min(widthPixels, width);
  int minHedight = Math.min(heightPixels, hedight);
  setMeasuredDimension(Math.min(minWidth, minHedight), Math.min(minWidth, minHedight));
 }
 
 @Override
 protected void onDraw(Canvas canvas) {
  int center = this.getWidth() / 2;
  int radius = center - circleWidth / 2;
 
  drawCircle(canvas, center, radius); // 绘制进度圆弧
  drawText(canvas, center);
 }
 
 /**
  * 绘制进度圆弧
  *
  * @param canvas 画布对象
  * @param center 圆心的x和y坐标
  * @param radius 圆的半径
  */
 private void drawCircle(Canvas canvas, int center, int radius) {
  circlePaint.setShader(null); // 清除上一次的shader
  circlePaint.setColor(firstColor); // 设置底部圆环的颜色，这里使用第一种颜色
  circlePaint.setStyle(Paint.Style.STROKE); // 设置绘制的圆为空心
  canvas.drawCircle(center, center, radius, circlePaint); // 画底部的空心圆
  RectF oval = new RectF(center - radius, center - radius, center + radius, center + radius); // 圆的外接正方形
  if (isShowGradient) {
   // 绘制颜色渐变圆环
   // shader类是Android在图形变换中非常重要的一个类。Shader在三维软件中我们称之为着色器，其作用是来给图像着色。
   LinearGradient linearGradient = new LinearGradient(circleWidth, circleWidth, getMeasuredWidth()
     - circleWidth, getMeasuredHeight() - circleWidth, colorArray, null, Shader.TileMode.MIRROR);
   circlePaint.setShader(linearGradient);
  }
  circlePaint.setShadowLayer(10, 10, 10, Color.BLUE);
  circlePaint.setColor(secondColor); // 设置圆弧的颜色
  circlePaint.setStrokeCap(Paint.Cap.ROUND); // 把每段圆弧改成圆角的
 
  alphaAngle = currentValue * 360.0f / maxValue * 1.0f; // 计算每次画圆弧时扫过的角度，这里计算要注意分母要转为float类型，否则alphaAngle永远为0
  canvas.drawArc(oval, -90, alphaAngle, false, circlePaint);
 }
 
 /**
  * 绘制文字
  *
  * @param canvas 画布对象
  * @param center 圆心的x和y坐标
  */
 private void drawText(Canvas canvas, int center) {
  int result = ((maxValue - currentValue) * (duration / 1000) / maxValue); // 计算进度
  String percent;
  if (maxValue == currentValue) {
   percent = "完成";
   textPaint.setTextSize(centerTextSize); // 设置要绘制的文字大小
  } else {
   percent = (result / 60 < 10 ? "0" + result / 60 : result / 60) + ":" + (result % 60 < 10 ? "0" + result % 60 : result % 60);
//   percent = result+"秒";
   textPaint.setTextSize(centerTextSize+centerTextSize/3); // 设置要绘制的文字大小
  }
  textPaint.setTextAlign(Paint.Align.CENTER); // 设置文字居中，文字的x坐标要注意
  textPaint.setColor(centerTextColor); // 设置文字颜色
 
  textPaint.setStrokeWidth(0); // 注意此处一定要重新设置宽度为0,否则绘制的文字会重叠
  Rect bounds = new Rect(); // 文字边框
  textPaint.getTextBounds(percent, 0, percent.length(), bounds); // 获得绘制文字的边界矩形 
  FontMetricsInt fontMetrics = textPaint.getFontMetricsInt(); // 获取绘制Text时的四条线 
  int baseline = center + (fontMetrics.bottom - fontMetrics.top) / 2 - fontMetrics.bottom; // 计算文字的基线  canvas.drawText(percent, center, baseline, textPaint); // 绘制表示进度的文字
 
 }
 
 /**
  * 设置圆环的宽度
  *
  * @param width
  */
 public void setCircleWidth(int width) {
  this.circleWidth = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, width, getResources()
    .getDisplayMetrics());
  circlePaint.setStrokeWidth(circleWidth);
  //一般只是希望在View发生改变时对UI进行重绘。invalidate()方法系统会自动调用 View的onDraw()方法。
  invalidate();
 }
 
 /**
  * 设置圆环的底色，默认为亮灰色LTGRAY
  *
  * @param color
  */
 public void setFirstColor(int color) {
  this.firstColor = color;
  circlePaint.setColor(firstColor);
  //一般只是希望在View发生改变时对UI进行重绘。invalidate()方法系统会自动调用 View的onDraw()方法。
  invalidate();
 }
 
 /**
  * 设置进度条的颜色，默认为蓝色<br>
  *
  * @param color
  */
 public void setSecondColor(int color) {
  this.secondColor = color;
  circlePaint.setColor(secondColor);
  //一般只是希望在View发生改变时对UI进行重绘。invalidate()方法系统会自动调用 View的onDraw()方法。
  invalidate();
 }
 
 /**
  * 设置进度条渐变色颜色数组
  *
  * @param colors 颜色数组，类型为int[]
  */
 public void setColorArray(int[] colors) {
  this.colorArray = colors;
  //一般只是希望在View发生改变时对UI进行重绘。invalidate()方法系统会自动调用 View的onDraw()方法。
  invalidate();
 }
 
 
 /**
  * 按进度显示百分比，可选择是否启用数字动画
  *
  * @param duration 动画时长
  */
 public void setDuration(int duration, OnFinishListener listener) {
   this.listener = listener;
  this.duration = duration + 1000;
  if (animator != null) {
   animator.cancel();
  } else {
   animator = ValueAnimator.ofInt(0, maxValue);
   animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
    @Override
    public void onAnimationUpdate(ValueAnimator animation) {
     currentValue = (int) animation.getAnimatedValue();
     //一般只是希望在View发生改变时对UI进行重绘。invalidate()方法系统会自动调用 View的onDraw()方法。
     invalidate();
     if (maxValue == currentValue && CountDownProgressBar.this.listener != null) {
      CountDownProgressBar.this.listener.onFinish();
     }
    }
   });
   animator.setInterpolator(new LinearInterpolator());
  }
  animator.setDuration(duration);
  animator.start();
 }
 
 public interface OnFinishListener {
  void onFinish();
 }
 
 public void setOnFinishListener(OnFinishListener listener) {
  this.listener = listener;
 }
 
 public static int px2dip(int pxValue) {
  final float scale = Resources.getSystem().getDisplayMetrics().density;
  return (int) (pxValue / scale + 0.5f);
 }
 
 
 public static float dip2px(float dipValue) {
  final float scale = Resources.getSystem().getDisplayMetrics().density;
  return (dipValue * scale + 0.5f);
 }
} 

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 xmlns:app="http://schemas.android.com/apk/res-auto"
 android:orientation="vertical">
<Button
 android:layout_width="match_parent"
 android:text="开始"
 android:id="@+id/btn_start"
 android:layout_height="wrap_content" />
 <com.daodaojk.myapplication.view.CountDownProgressBar
  android:id="@+id/cpb_countdown"
  android:layout_width="200dp"
  android:layout_marginTop="100dp"
  android:layout_gravity="center_horizontal"
  app:countDown_centerTextSize="25dp"
  app:countDown_circleWidth="4dp"
  app:countDown_firstColor="@color/text_gray_ccc"
  app:countDown_secondColor="@color/text_blue"
  app:countDown_isShowGradient="true"
  app:countDown_centerTextColor="#2395FF"
  android:layout_height="200dp" />
</LinearLayout>

package com.daodaojk.myapplication.ui;
 
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
 
import com.daodaojk.myapplication.R;
import com.daodaojk.myapplication.view.CountDownProgressBar;
 
public class CountDownActivity extends AppCompatActivity {
 
 private CountDownProgressBar cpb_countdown;
 
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_count_down);
  Button btn_start = findViewById(R.id.btn_start);
  cpb_countdown = (CountDownProgressBar) findViewById(R.id.cpb_countdown);
  btn_start.setOnClickListener(new View.OnClickListener() {
   @Override
   public void onClick(View v) {
    cpb_countdown.setDuration(10000, new CountDownProgressBar.OnFinishListener() {
     @Override
     public void onFinish() {
      Toast.makeText(CountDownActivity.this, "完成了", Toast.LENGTH_SHORT).show();
     }
    });
   }
  });
 }
}