如今APP越来越多,我们每天所使用的的软件也越来越多,可是在我们不付费的情况下,App制造商如何实现,实现收入甚至是盈利呢?答案就是在我们打开软件所必须经过的地方穿插广告,当然为了顾及用户的感受,一般都会以倒计时的形式展示给用户,用户可以选择跳过.可能是因为自己的强迫症,总想着是怎么做的,自己就尝试了一下,分享给大家的同时,顺便加深自己的理解.效果如图：

1.为了满足产品和设计,先搞几个自定义属性

1)内层背景
2)数字的颜色
3)外层圆环宽度
4)文字大小
5)外层圆环颜色
6)圆的半径

这里,我的外环颜色和文字颜色相同,具体的自定义属性如下:

<declare-styleable name="AdTimePickView"> <attr name="mSmallCircleBg" format="color"></attr> <attr name="mTextSize1" format="dimension"></attr> <attr name="mTextColor1" format="color"></attr> <attr name="mProgressWidth" format="dimension"></attr> <attr name="mRadius" format="dimension"></attr> </declare-styleable>

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2.在自定义View的构造方法中读取自定义属性:

mProgressViewWidth = typedArray.getDimensionPixelSize(R.styleable.AdTimePickView_mProgressWidth, DEFAULT_PROGRESS_WIDTH); mRadius = typedArray.getDimensionPixelSize(R.styleable.AdTimePickView_mRadius1, DEFAULT_RADIUS); mSmallCircleBg = typedArray.getColor(R.styleable.AdTimePickView_mSmallCircleBg, Color.parseColor(DEFAULT_BG_COLOR)); mTextSize = typedArray.getDimensionPixelSize(R.styleable.AdTimePickView_mTextSize1, DEFAULT_TEXT_SIZE); mTextColor = typedArray.getColor(R.styleable.AdTimePickView_mTextColor1, Color.parseColor(DEFAULT_TEXT_COLOR));

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3.重写onMeasure()方法,

根据宽高得出半径,为什么不适用自定义半径呢?因为根据宽高得出的半径才是这个View的内切圆半径,自定义半径只是为了在根据宽高无法得出半径的情况下才使用的.

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); mWidth = getViewSize(widthMeasureSpec, 0); mHeight = getViewSize(heightMeasureSpec, 1); mRadius = Math.min(mWidth, mHeight) / 2; setMeasuredDimension(mWidth, mHeight); }

getViewSize方法如下：

private int getViewSize(int viewMeasureSpec, int type) { int viewValue = 0; int viewSize = MeasureSpec.getSize(viewMeasureSpec); int viewMode = MeasureSpec.getMode(viewMeasureSpec); if (MeasureSpec.EXACTLY == viewMode) { viewValue = viewSize; if (type == 0) { mCirCleX = viewSize / 2; } else { mCircleY = viewSize / 2; } } else { if (type == 0) { mCirCleX = mRadius; } else { mCircleY = mRadius; } viewValue = 2 * (mRadius + mProgressViewWidth); } return viewValue; }

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4.onDraw方法进行绘制

1)绘制内层圆

canvas.drawCircle(mCirCleX, mCircleY, (float) (mRadius - 1.5 * mProgressViewWidth), mPaint);

2)绘制文字,要计算好文字的位置,保持居中

Rect textRect = getTextRect(String.valueOf(mAdTIme)); Paint.FontMetrics fontMetrics = mTextPaint.getFontMetrics(); int baseLine = (int) (mHeight / 2 + (fontMetrics.descent - fontMetrics.ascent) / 2 - fontMetrics.descent); int x = mWidth / 2 - textRect.width() / 2; canvas.drawText(String.valueOf(mAdTIme), x, baseLine, mTextPaint);//获取绘制内容的Rect private Rect getTextRect(String centerContent) { Rect rect = new Rect(); mTextPaint.getTextBounds(centerContent, 0, centerContent.length(), rect); return rect; }

3)绘制外层不断刷新的圆环

原理:从360度开始每隔一段时间进行圆弧绘制,角度分别为:360,359,1,0,因此需要一个轮询器,不断的去绘制刷新.
绘制圆弧的代码：

//保存Canvans的状态,因为绘制其他地方时,Canvas坐标系不需要变化 canvas.save(); //将坐标系围绕View的中心逆时针旋转90度数,为了从正上方开始绘制 canvas.rotate(-90, mCirCleX, mCircleY); //计算圆弧的RectF RectF rectF = new RectF(mCirCleX - mRadius + mProgressViewWidth, mCirCleX - mRadius + mProgressViewWidth, mCirCleX + mRadius - mProgressViewWidth, mCirCleX + mRadius - mProgressViewWidth); //第四个参数表示逆时针还是顺时针绘制 canvas.drawArc(rectF, 0, -mCurrentAngle, false, mPaint); //恢复坐标系 canvas.restore();

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5.刷新的轮询器

1)使用RxAndroid和lambda实现

//interval操作符：从1开始每隔一段时间发射递增的数Observable.interval(1, TIME_DIFF, TimeUnit.MILLISECONDS) //map操作符将发射的数据转换成我们需要的数据 .map(value -> { return countAngel - value.intValue(); }) //限制发射的数据个数，让其停止，负责会一直发射下去 .limit(361) //接收结果并处理 .subscribe(action -> { if (action % 72 == 0) { mAdTIme = action / 72; } mCurrentAngle = action; AdTimePickView.this.postInvalidate(); });

2)使用线程的方式实现

new Thread(new Runnable() { @Override public void run() { for (int i = 360; i>=0;i--){ try { Thread.sleep(100); } catch (InterruptedException e) { e.printStackTrace(); } if (i % 72 == 0) { mAdTIme = i / 72; } mCurrentAngle = i; AdTimePickView.this.postInvalidate(); } } }).start();

OK,这样我们的广告倒计时View就完成了,欢迎大家指正.

附:整个自定义View的代码

public class AdTimePickView extends View {private Paint mPaint;private Paint mTextPaint;//大圆半径private int mRadius = 200;//内层小圆背景private int mSmallCircleBg = Color.parseColor("#66f1679b");//小圆外层线条宽度private int mProgressViewWidth = 10;private float mCurrentAngle;private static final int TIME_DIFF = 25;//圆心坐标private int mCirCleX;private int mCircleY;//测量之后View的宽高,绘制中心文字时需要用到private int mWidth;private int mHeight;//中心文字的大小与样式private int mTextSize;private int mTextColor;//广告总时间private int mAdTIme = 5;private Context mContext;public AdTimePickView(Context context) { this(context, null);}public AdTimePickView(Context context, AttributeSet attrs) { this(context, attrs, 0);}public AdTimePickView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.AdTimePickView, defStyleAttr, 0); mProgressViewWidth = typedArray.getDimensionPixelSize(R.styleable.AdTimePickView_mProgressWidth, 10); mRadius = typedArray.getDimensionPixelSize(R.styleable.AdTimePickView_mRadius1, 100); mSmallCircleBg = typedArray.getColor(R.styleable.AdTimePickView_mSmallCircleBg, Color.parseColor("#66f1679b")); mTextSize = typedArray.getDimensionPixelSize(R.styleable.AdTimePickView_mTextSize1, 20); mTextColor = typedArray.getColor(R.styleable.AdTimePickView_mTextColor1, Color.parseColor("#333333")); //注意资源的回收 typedArray.recycle(); this.mContext = context; init();}private void init() { mPaint = new Paint(Paint.ANTI_ALIAS_FLAG); mPaint.setAntiAlias(true); mTextPaint = new Paint(Paint.ANTI_ALIAS_FLAG); mTextPaint.setColor(mTextColor); mTextPaint.setTextSize(mTextSize); mTextPaint.setStyle(Paint.Style.FILL); mTextPaint.setAntiAlias(true);}@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); mWidth = getViewSize(widthMeasureSpec, 0); mHeight = getViewSize(heightMeasureSpec, 1); //大半径 mRadius = Math.min(mWidth, mHeight) / 2; setMeasuredDimension(mWidth, mHeight);}private int getViewSize(int viewMeasureSpec, int type) { int viewValue = 0; int viewSize = MeasureSpec.getSize(viewMeasureSpec); int viewMode = MeasureSpec.getMode(viewMeasureSpec); if (MeasureSpec.EXACTLY == viewMode) { viewValue = viewSize; if (type == 0) { mCirCleX = viewSize / 2; } else { mCircleY = viewSize / 2; } } else { if (type == 0) { mCirCleX = mRadius; } else { mCircleY = mRadius; } viewValue = 2 * (mRadius + mProgressViewWidth); } return viewValue;}@Overrideprotected void onDraw(Canvas canvas) { super.onDraw(canvas); mPaint.setColor(mSmallCircleBg); mPaint.setStyle(Paint.Style.FILL); canvas.drawCircle(mCirCleX, mCircleY, (float) (mRadius - 1.5 * mProgressViewWidth), mPaint); //设置画笔状态 mPaint.setColor(mTextColor); mPaint.setStyle(Paint.Style.STROKE); mPaint.setStrokeWidth(mProgressViewWidth); //保存Canvans的状态 canvas.save(); //将坐标系围绕View的中心逆时针旋转90度数 canvas.rotate(-90, mCirCleX, mCircleY); RectF rectF = new RectF(mCirCleX - mRadius + mProgressViewWidth, mCirCleX - mRadius + mProgressViewWidth, mCirCleX + mRadius - mProgressViewWidth, mCirCleX + mRadius - mProgressViewWidth); //第四个参数表示逆时针还是顺时针绘制 canvas.drawArc(rectF, 0, -mCurrentAngle, false, mPaint); canvas.restore(); Rect textRect = getTextRect(String.valueOf(mAdTIme)); Paint.FontMetrics fontMetrics = mTextPaint.getFontMetrics(); int baseLine = (int) (mHeight / 2 + (fontMetrics.descent - fontMetrics.ascent) / 2 - fontMetrics.descent); int x = mWidth / 2 - textRect.width() / 2; canvas.drawText(String.valueOf(mAdTIme), x, baseLine, mTextPaint);}private Rect getTextRect(String centerContent) { Rect rect = new Rect(); mTextPaint.getTextBounds(centerContent, 0, centerContent.length(), rect); return rect;}public void refresh() { final int countAngel = 360; Observable.interval(1, TIME_DIFF, TimeUnit.MILLISECONDS) .map(value -> { return countAngel - value.intValue(); }) .limit(361) .subscribe(action -> { if (action % 72 == 0) { mAdTIme = action / 72; } mCurrentAngle = action; AdTimePickView.this.postInvalidate(); });}}

以上所述是小编给大家介绍的Android 自定义闪屏页广告倒计时view效果，希望对大家有所帮助，如果大家有任何疑问欢迎给我留言，小编会及时回复大家的，在此也非常感谢大家对网站的支持！