android 圆环倒计时控件

1.自定义属性

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <!-- 倒计时控件属性 -->
    <declare-styleable name="CountDownView">
        <!--颜色-->
        <attr name="ringColor" format="color" />
        <!-- 进度文本的字体大小 -->
        <attr name="progressTextSize" format="dimension" />
        <!-- 圆环宽度 -->
        <attr name="ringWidth" format="float" />
        <!--进度文本颜色-->
        <attr name="progressTextColor" format="color"/>
        <!--倒计时-->
        <attr name="countdownTime" format="integer"/>
    </declare-styleable>
</resources>

2.自定义view

public class CountDownView extends View {
    //圆环颜色
    private int mRingColor;
    //圆环宽度
    private float mRingWidth;
    //圆环进度值文本大小
    private int mRingProgessTextSize;
    //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 mProgessTextColor;
    private int mCountdownTime;
    private float mCurrentProgress;


    ValueAnimator valueAnimator;

    /**
     * 监听事件
     */
    private OnCountDownListener mListener;

    public CountDownView(Context context) {
        this(context, null);

    }

    public CountDownView(Context context, @Nullable AttributeSet attrs) {
        this(context, attrs, 0);


    }

    public CountDownView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
       // init();

        /**
         * 获取相关属性值
         */
        TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.CountDownView);
        mRingColor = typedArray.getColor(R.styleable.CountDownView_ringColor, context.getResources().getColor(R.color.colorAccent));
        mRingWidth = typedArray.getFloat(R.styleable.CountDownView_ringWidth, 40);
        mRingProgessTextSize = typedArray.getDimensionPixelSize(R.styleable.CountDownView_progressTextSize, 20);
        mProgessTextColor = typedArray.getColor(R.styleable.CountDownView_progressTextColor, context.getResources().getColor(R.color.colorAccent));
        mCountdownTime = typedArray.getInteger(R.styleable.CountDownView_countdownTime, 60);
        typedArray.recycle();
        mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mPaint.setAntiAlias(true);
        this.setWillNotDraw(false);

    }

    @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);
    }


    /**
     * 设置倒计时间 单位秒
     * @param mCountdownTime
     */
    public void setCountdownTime(int mCountdownTime) {
        this.mCountdownTime = mCountdownTime;

        invalidate();

    }

//    public CountDownView(Context context, @Nullable AttributeSet attrs, int defStyleAttr, int defStyleRes) {
//        super(context, attrs, defStyleAttr, defStyleRes);
//    }

    /**
     * 动画
     * @param countdownTime
     * @return
     */
    private ValueAnimator getValueAnimator(long countdownTime) {
        ValueAnimator valueAnimator = ValueAnimator.ofFloat(0, 100);
        valueAnimator.setDuration(countdownTime);
        valueAnimator.setInterpolator(new LinearInterpolator());
        valueAnimator.setRepeatCount(0);
        return valueAnimator;
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        /**
         *圆环
         */
        //颜色
        mPaint.setColor(mRingColor);
        //空心
        mPaint.setStyle(Paint.Style.STROKE);
        //宽度
        mPaint.setStrokeWidth(mRingWidth);
        canvas.drawArc(mRectF, -90, mCurrentProgress - 360, false, mPaint);
        //绘制文本
        Paint textPaint = new Paint();
        textPaint.setAntiAlias(true);
        textPaint.setTextAlign(Paint.Align.CENTER);
        String text = mCountdownTime - (int) (mCurrentProgress / 360f * mCountdownTime) + "";
        textPaint.setTextSize(mRingProgessTextSize);
        textPaint.setColor(mProgessTextColor);

        //文字居中显示
        Paint.FontMetricsInt fontMetrics = textPaint.getFontMetricsInt();
        int baseline = (int) ((mRectF.bottom + mRectF.top - fontMetrics.bottom - fontMetrics.top) / 2);
        canvas.drawText(text, mRectF.centerX(), baseline, textPaint);
    }


    /**
     * 开始倒计时
     */
    public void startCountDown() {
        valueAnimator = getValueAnimator(mCountdownTime * 1000);
        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();
        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();
                }
            }

        });
    }


    /**
     * 停止倒计时
     */
    public void stopCountDdwn(){

        valueAnimator.cancel();


    }
    public void setOnCountDownListener(OnCountDownListener mListener) {
        this.mListener = mListener;
    }
}

3.布局文件

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <demo.com.countdowndemo.CountDownView
        android:id="@+id/countDownView"
        android:layout_width="50dp"
        android:layout_height="50dp"
        app:countdownTime="5"
        app:ringWidth="2"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>

4.Activity

public class MainActivity extends AppCompatActivity {

    CountDownView countDownView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

         countDownView = findViewById(R.id.countDownView);

        countDownView.setOnCountDownListener(new OnCountDownListener() {
            @Override
            public void countDownFinished() {
                //倒计时结束
                //countDownView.setCountdownTime(10);

                Intent intent = new Intent(MainActivity.this, Main2Activity.class);
                startActivity(intent);
            }
        });

        countDownView.startCountDown();


        countDownView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                countDownView.stopCountDdwn();
                Intent intent = new Intent(MainActivity.this, Main2Activity.class);
                startActivity(intent);
            }
        });
    }
}