Android 自定义圆环倒计时控件

版权声明：转载请标明出处! https://blog.csdn.net/baidu_36619149/article/details/80163745

先来一张最终效果图:

主要思路: 在画渐变色圆环的时候,设置一个属性动画,根据属性动画的执行时长,来作为倒计时的时长.监听属性动画的进度,来达到 倒计时的目的.

二话不说,直接贴代码.具体实现思路都在注释上.

自定义属性:

<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>

主要代码:

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,方法见http://blog.csdn.net/harvic880925/article/details/50423762  
        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布局:

<?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>

页面调用:

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();
                    }
                });
            }
        });
    }
}

如果有什么不对的地方或者疑问,欢迎指正和提出(〃'▽'〃)