本篇文章给大家分享的是有关Android中如何实现倒计时功能，小编觉得挺实用的，因此分享给大家学习，希望大家阅读完这篇文章后可以有所收获，话不多说，跟着小编一起来看看吧。
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1.Handler2.Timer3.RxJava4.ValueAnimator5.其他
这些方式中，我选择了ValueAnimator,主要是它的API比较友好，不需要我们去封装太多东西,具体的使用方式我就不单独写了，下面的代码都有备注
代码实现：
package com.example.countdownview;import android.animation.Animator;import android.animation.AnimatorListenerAdapter;import android.animation.ValueAnimator;import android.content.Context;import android.content.res.TypedArray;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.RectF;import android.util.AttributeSet;import android.view.View;import android.view.animation.LinearInterpolator;public class CountDownView extends View { //圆轮颜色 private int mRingColor; //圆轮宽度 private float mRingWidth; //宽度 private int mWidth; //高度 private int mHeight; private Paint mPaint; //圆环的矩形区域 private RectF mRectF; // private int mCountdownTime; private float mCurrentProgress; private OnCountDownFinishListener mListener; ValueAnimator valueAnimator; public CountDownView(Context context) { this(context, null); } public CountDownView(Context context, AttributeSet attrs) { this(context, attrs, 0); } public CountDownView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CountDownView); mRingColor = a.getColor(R.styleable.CountDownView_ringColor, Color.RED); mCountdownTime = a.getInteger(R.styleable.CountDownView_countdownTime, 10); mRingWidth=a.getDimension(R.styleable.CountDownView_ringWidth,2); a.recycle(); mPaint = new Paint(Paint.ANTI_ALIAS_FLAG); /** *圆环 */ //颜色 mPaint.setColor(mRingColor); //空心 mPaint.setStyle(Paint.Style.STROKE); mPaint.setAntiAlias(true); // 消除锯齿 //宽度 mPaint.setStrokeWidth(mRingWidth); } public void setCountdownTime(int mCountdownTime) { this.mCountdownTime = mCountdownTime; } @Override protected void onLayout(boolean changed, int left, int top, int right, int bottom) { super.onLayout(changed, left, top, right, bottom); mWidth = getMeasuredWidth(); mHeight = getMeasuredHeight(); mRectF = new RectF(0 + mRingWidth / 2, 0 + mRingWidth / 2, mWidth - mRingWidth / 2, mHeight - mRingWidth / 2); } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); canvas.drawArc(mRectF, -90, mCurrentProgress, false, mPaint); } private ValueAnimator getValA(long countdownTime) { ValueAnimator valueAnimator = ValueAnimator.ofFloat(0, 100); valueAnimator.setDuration(countdownTime); valueAnimator.setInterpolator(new LinearInterpolator()); valueAnimator.setRepeatCount(0); return valueAnimator; } /** * 开始倒计时 */ public void startCountDown() { setClickable(false); valueAnimator = getValA(mCountdownTime * 1000); //状态更新监听 valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator animation) { float i = Float.valueOf(String.valueOf(animation.getAnimatedValue())); mCurrentProgress = (int) (360 * (i / 100f)); invalidate(); } }); valueAnimator.start(); //状态变化结束监听 valueAnimator.addListener(new AnimatorListenerAdapter() { @Override public void onAnimationEnd(Animator animation) { super.onAnimationEnd(animation); //倒计时结束回调 if (mListener != null) { mListener.countDownFinished(); } setClickable(true); } }); } /** * 恢复 */ public void resumeCountDown(){ if (valueAnimator!=null){ valueAnimator.resume(); } } /** * 暂停 */ public void pauseCountDown(){ if (valueAnimator!=null){ valueAnimator.pause(); } } /** * 停止倒计时 */ public void stopCountDown(){ if (valueAnimator!=null){ valueAnimator.cancel(); } } public void setCountDownFinishListener(OnCountDownFinishListener mListener) { this.mListener = mListener; } public interface OnCountDownFinishListener { void countDownFinished(); }}
以上就是Android中如何实现倒计时功能，小编相信有部分知识点可能是我们日常工作会见到或用到的。希望你能通过这篇文章学到更多知识。更多详情敬请关注创新互联行业资讯频道。
