Android自定义View模仿虎扑直播界面的打赏按钮功能

2019-12-12 03:11:50

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前言

作为一个资深篮球爱好者，我经常会用虎扑app看比赛直播，后来注意到文字直播界面右下角加了两个按钮，可以在直播过程中送虎扑币，为自己支持的球队加油。

具体的效果如下图所示：

我个人觉得挺好玩的，所以决定自己实现下这个按钮，废话不多说，先看实现的效果吧：

这个效果看起来和popupwindow差不多，但我是采用自定义view的方式来实现，下面说说过程。

实现过程

首先从虎扑的效果可以看到，它这两个按钮时浮在整个界面之上的，所以它需要和FrameLayout结合使用，因此我让它的宽度跟随屏幕大小，高度根据dpi固定，它的实际尺寸时这样的：

另外这个view初始化出来我们看到可以分为三块，背景圆、圆内文字、圆上方数字，所以正常状态下，只需要在onDraw方法中画出这三块内容即可。先在初始化方法中将自定义的属性和画笔以及初始化数据准备好：

private void init(Context context, AttributeSet attrs) {//获取自定义属性TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.HoopView);mThemeColor = typedArray.getColor(R.styleable.HoopView_theme_color, Color.YELLOW);mText = typedArray.getString(R.styleable.HoopView_text);mCount = typedArray.getString(R.styleable.HoopView_count);mBgPaint = new Paint();mBgPaint.setAntiAlias(true);mBgPaint.setColor(mThemeColor);mBgPaint.setAlpha(190);mBgPaint.setStyle(Paint.Style.FILL);mPopPaint = new Paint();mPopPaint.setAntiAlias(true);mPopPaint.setColor(Color.LTGRAY);mPopPaint.setAlpha(190);mPopPaint.setStyle(Paint.Style.FILL_AND_STROKE);mTextPaint = new TextPaint();mTextPaint.setAntiAlias(true);mTextPaint.setColor(mTextColor);mTextPaint.setTextSize(context.getResources().getDimension(R.dimen.hoop_text_size));mCountTextPaint = new TextPaint();mCountTextPaint.setAntiAlias(true);mCountTextPaint.setColor(mThemeColor);mCountTextPaint.setTextSize(context.getResources().getDimension(R.dimen.hoop_count_text_size));typedArray.recycle();mBigRadius = context.getResources().getDimension(R.dimen.hoop_big_circle_radius);mSmallRadius = context.getResources().getDimension(R.dimen.hoop_small_circle_radius);margin = (int) context.getResources().getDimension(R.dimen.hoop_margin);mHeight = (int) context.getResources().getDimension(R.dimen.hoop_view_height);countMargin = (int) context.getResources().getDimension(R.dimen.hoop_count_margin);mDatas = new String[] {"1", "10", "100"};// 计算背景框改变的长度，默认是三个按钮mChangeWidth = (int) (2 * mSmallRadius * 3 + 4 * margin);}

在onMeasure中测出view的宽度后，根据宽度计算出背景圆的圆心坐标和一些相关的数据值。

@Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {int widthSize = MeasureSpec.getSize(widthMeasureSpec);mWidth = getDefaultSize(widthSize, widthMeasureSpec);setMeasuredDimension(mWidth, mHeight);// 此时才测出了mWidth值，再计算圆心坐标及相关值cx = mWidth - mBigRadius;cy = mHeight - mBigRadius;// 大圆圆心circle = new PointF(cx, cy);// 三个按钮的圆心circleOne = new PointF(cx - mBigRadius - mSmallRadius - margin, cy);circleTwo = new PointF(cx - mBigRadius - 3 * mSmallRadius - 2 * margin, cy);circleThree = new PointF(cx - mBigRadius - 5 * mSmallRadius - 3 * margin, cy);// 初始的背景框的边界即为大圆的四个边界点top = cy - mBigRadius;bottom = cy + mBigRadius;}

因为这里面涉及到点击按钮展开和收缩的过程，所以我定义了如下几种状态，只有在特定的状态下才能进行某些操作。

private int mState = STATE_NORMAL;//当前展开收缩的状态private boolean mIsRun = false;//是否正在展开或收缩//正常状态public static final int STATE_NORMAL = 0;//按钮展开public static final int STATE_EXPAND = 1;//按钮收缩public static final int STATE_SHRINK = 2;//正在展开public static final int STATE_EXPANDING = 3;//正在收缩public static final int STATE_SHRINKING = 4;

接下来就执行onDraw方法了，先看看代码：

@Override protected void onDraw(Canvas canvas) {switch (mState) {case STATE_NORMAL:drawCircle(canvas);break;case STATE_SHRINK:case STATE_SHRINKING:drawBackground(canvas);break;case STATE_EXPAND:case STATE_EXPANDING:drawBackground(canvas);break;}drawCircleText(canvas);drawCountText(canvas);}

圆上方的数字和圆内的文字是整个过程中一直存在的，所以我将这两个操作放在switch之外，正常状态下绘制圆和之前两部分文字，点击展开时绘制背景框展开过程和文字，展开状态下再次点击绘制收缩过程和文字，当然在绘制背景框的方法中也需要不断绘制大圆，大圆也是一直存在的。

上面的绘制方法：

/** * 画背景大圆 * @param canvas */private void drawCircle(Canvas canvas) {left = cx - mBigRadius;right = cx + mBigRadius;canvas.drawCircle(cx, cy, mBigRadius, mBgPaint);}/** * 画大圆上面表示金币数的文字 * @param canvas */private void drawCountText(Canvas canvas) {canvas.translate(0, -countMargin);//计算文字的宽度float textWidth = mCountTextPaint.measureText(mCount, 0, mCount.length());canvas.drawText(mCount, 0, mCount.length(), (2 * mBigRadius - textWidth - 35) / 2, 0.2f, mCountTextPaint);}/** * 画大圆内的文字 * @param canvas */private void drawCircleText(Canvas canvas) {StaticLayout layout = new StaticLayout(mText, mTextPaint, (int) (mBigRadius * Math.sqrt(2)), Layout.Alignment.ALIGN_CENTER, 1.0f, 0.0f, true);canvas.translate(mWidth - mBigRadius * 1.707f, mHeight - mBigRadius * 1.707f);layout.draw(canvas);canvas.save();}/** * 画背景框展开和收缩 * @param canvas */private void drawBackground(Canvas canvas) {left = cx - mBigRadius - mChange;right = cx + mBigRadius;canvas.drawRoundRect(left, top, right, bottom, mBigRadius, mBigRadius, mPopPaint);if ((mChange > 0) && (mChange <= 2 * mSmallRadius + margin)) {// 绘制第一个按钮canvas.drawCircle(cx - mChange, cy, mSmallRadius, mBgPaint);// 绘制第一个按钮内的文字canvas.drawText(mDatas[0], cx - (mBigRadius - mSmallRadius) - mChange, cy + 15, mTextPaint);} else if ((mChange > 2 * mSmallRadius + margin) && (mChange <= 4 * mSmallRadius + 2 * margin)) {// 绘制第一个按钮canvas.drawCircle(cx - mBigRadius - mSmallRadius - margin, cy, mSmallRadius, mBgPaint);// 绘制第一个按钮内的文字canvas.drawText(mDatas[0], cx - mBigRadius - mSmallRadius - margin - 20, cy + 15, mTextPaint);// 绘制第二个按钮canvas.drawCircle(cx - mChange, cy, mSmallRadius, mBgPaint);// 绘制第二个按钮内的文字canvas.drawText(mDatas[1], cx - mChange - 20, cy + 15, mTextPaint);} else if ((mChange > 4 * mSmallRadius + 2 * margin) && (mChange <= 6 * mSmallRadius + 3 * margin)) {// 绘制第一个按钮canvas.drawCircle(cx - mBigRadius - mSmallRadius - margin, cy, mSmallRadius, mBgPaint);// 绘制第一个按钮内的文字canvas.drawText(mDatas[0], cx - mBigRadius - mSmallRadius - margin - 16, cy + 15, mTextPaint);// 绘制第二个按钮canvas.drawCircle(cx - mBigRadius - 3 * mSmallRadius - 2 * margin, cy, mSmallRadius, mBgPaint);// 绘制第二个按钮内的文字canvas.drawText(mDatas[1], cx - mBigRadius - 3 * mSmallRadius - 2 * margin - 25, cy + 15, mTextPaint);// 绘制第三个按钮canvas.drawCircle(cx - mChange, cy, mSmallRadius, mBgPaint);// 绘制第三个按钮内的文字canvas.drawText(mDatas[2], cx - mChange - 34, cy + 15, mTextPaint);} else if (mChange > 6 * mSmallRadius + 3 * margin) {// 绘制第一个按钮canvas.drawCircle(cx - mBigRadius - mSmallRadius - margin, cy, mSmallRadius, mBgPaint);// 绘制第一个按钮内的文字canvas.drawText(mDatas[0], cx - mBigRadius - mSmallRadius - margin - 16, cy + 15, mTextPaint);// 绘制第二个按钮canvas.drawCircle(cx - mBigRadius - 3 * mSmallRadius - 2 * margin, cy, mSmallRadius, mBgPaint);// 绘制第二个按钮内的文字canvas.drawText(mDatas[1], cx - mBigRadius - 3 * mSmallRadius - 2 * margin - 25, cy + 15, mTextPaint);// 绘制第三个按钮canvas.drawCircle(cx - mBigRadius - 5 * mSmallRadius - 3 * margin, cy, mSmallRadius, mBgPaint);// 绘制第三个按钮内的文字canvas.drawText(mDatas[2], cx - mBigRadius - 5 * mSmallRadius - 3 * margin - 34, cy + 15, mTextPaint);}drawCircle(canvas);}

然后是点击事件的处理，只有触摸点在大圆内时才会触发展开或收缩的操作，点击小圆时提供了一个接口给外部调用。

@Override public boolean onTouchEvent(MotionEvent event) {int action = event.getAction();switch (action) {case MotionEvent.ACTION_DOWN://如果点击的时候动画在进行，不处理if (mIsRun) return true;PointF pointF = new PointF(event.getX(), event.getY());if (isPointInCircle(pointF, circle, mBigRadius)) { //如果触摸点在大圆内，根据弹出方向弹出或者收缩按钮if ((mState == STATE_SHRINK || mState == STATE_NORMAL) && !mIsRun) {//展开mIsRun = true;//这是必须先设置true，因为onAnimationStart在onAnimationUpdate之后才调用showPopMenu();} else {//收缩mIsRun = true;hidePopMenu();}} else { //触摸点不在大圆内if (mState == STATE_EXPAND) { //如果是展开状态if (isPointInCircle(pointF, circleOne, mSmallRadius)) {listener.clickButton(this, Integer.parseInt(mDatas[0]));} else if (isPointInCircle(pointF, circleTwo, mSmallRadius)) {listener.clickButton(this, Integer.parseInt(mDatas[1]));} else if (isPointInCircle(pointF, circleThree, mSmallRadius)) {listener.clickButton(this, Integer.parseInt(mDatas[2]));}mIsRun = true;hidePopMenu();}}break;}return super.onTouchEvent(event);}

展开和收缩的动画是改变背景框的宽度属性的动画，并监听这个属性动画，在宽度值改变的过程中去重新绘制整个view。因为一开始我就确定了大圆小圆的半径和小圆与背景框之间的间距，所以初始化时已经计算好了背景框的宽度：

mChangeWidth = (int) (2 * mSmallRadius * 3 + 4 * margin);

/** * 弹出背景框 */private void showPopMenu() {if (mState == STATE_SHRINK || mState == STATE_NORMAL) {ValueAnimator animator = ValueAnimator.ofInt(0, mChangeWidth);animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {@Override public void onAnimationUpdate(ValueAnimator animation) {if (mIsRun) {mChange = (int) animation.getAnimatedValue();invalidate();} else {animation.cancel();mState = STATE_NORMAL;}}});animator.addListener(new AnimatorListenerAdapter() {@Override public void onAnimationStart(Animator animation) {super.onAnimationStart(animation);mIsRun = true;mState = STATE_EXPANDING;}@Override public void onAnimationCancel(Animator animation) {super.onAnimationCancel(animation);mIsRun = false;mState = STATE_NORMAL;}@Override public void onAnimationEnd(Animator animation) {super.onAnimationEnd(animation);mIsRun = false;//动画结束后设置状态为展开mState = STATE_EXPAND;}});animator.setDuration(500);animator.start();}}

/** * 隐藏弹出框 */private void hidePopMenu() {if (mState == STATE_EXPAND) {ValueAnimator animator = ValueAnimator.ofInt(mChangeWidth, 0);animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {@Override public void onAnimationUpdate(ValueAnimator animation) {if (mIsRun) {mChange = (int) animation.getAnimatedValue();invalidate();} else {animation.cancel();}}});animator.addListener(new AnimatorListenerAdapter() {@Override public void onAnimationStart(Animator animation) {super.onAnimationStart(animation);mIsRun = true;mState = STATE_SHRINKING;}@Override public void onAnimationCancel(Animator animation) {super.onAnimationCancel(animation);mIsRun = false;mState = STATE_EXPAND;}@Override public void onAnimationEnd(Animator animation) {super.onAnimationEnd(animation);mIsRun = false;//动画结束后设置状态为收缩mState = STATE_SHRINK;}});animator.setDuration(500);animator.start();}}

这个过程看起来是弹出或收缩，实际上宽度值每改变一点，就将所有的组件重绘一次，只是文字和大圆等内容的尺寸及位置都没有变化，只有背景框的宽度值在变，所以才有这种效果。

在xml中的使用：

<LinearLayoutandroid:layout_width="match_parent"android:layout_height="wrap_content"android:layout_alignParentBottom="true"android:layout_marginBottom="20dp"android:layout_alignParentRight="true"android:orientation="vertical"><com.xx.hoopcustomview.HoopViewandroid:id="@+id/hoopview1"android:layout_width="match_parent"android:layout_height="wrap_content"android:layout_marginRight="10dp"app:text="支持火箭"app:count="1358"app:theme_color="#31A129"/><com.xx.hoopcustomview.HoopViewandroid:id="@+id/hoopview2"android:layout_width="match_parent"android:layout_height="wrap_content"android:layout_marginRight="10dp"app:text="热火无敌"app:count="251"app:theme_color="#F49C11"/></LinearLayout>

activity中使用：

hoopview1 = (HoopView) findViewById(R.id.hoopview1);hoopview1.setOnClickButtonListener(new HoopView.OnClickButtonListener() {@Override public void clickButton(View view, int num) {Toast.makeText(MainActivity.this, "hoopview1增加了" + num, Toast.LENGTH_SHORT).show();}});

大致实现过程就是这样，与原始效果还是有点区别，我这个还有很多瑕疵，比如文字的位置居中问题，弹出或收缩时，小圆内的文字的旋转动画我没有实现。

总结

以上就是这篇文章的全部内容了，希望本文的内容对各位Android开发者们能带来一定的帮助，如果有疑问大家可以留言交流，谢谢大家对武林网的支持。

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