模仿百度红包福袋界面实例代码

新年到新年到，红包抢不停。在我抢红包的时候意外的发现了百度的福袋界面挺不错的，于是抽时间专门写篇文章来完成百度红包界面吧。

当然啦，这其实就是解锁界面的进化版本。不过其包含的知识点还是挺多的，写篇博文记录一下看看具体有哪些技术点啦。看看百度的效果图：

1.编程思路

看看界面，不难发现，其就是一个放入九张图片的容器，绘制其实可以在其上面另创建一个透明View负责绘制线与圆圈。下面我们将介绍一下实现过程。

㈠自定义ViewGroup

我们知道，自定义ViewGroup一定需要实现其onLayout()方法。该方法是设置子View位置与尺寸的时候调用。还有一个onMeasure()方法，该方法是测量view及其内容来确定view的宽度和高度。

㈡存储其点与圆的位置及绘制参数

当重回界面的时候，是不会保存上一次绘制界面的内容，必须存储以备重绘时候绘制到界面

㈢简单的缩放动画

㈣自定义View实现绘制界面

㈤绘制完成时，清除界面绘制内容，并且保证不连接重复图片

下面我们将完成这些步骤。

2.自定义ViewGroup

开始的任务就是将九张图片平均分布到图片的位置，显示在手机界面中。其代码如下：

public class LYJViewGroup extends ViewGroup implements LYJGestureDrawline.OnAnimationCallback{/*** 每个点区域的宽度*/private int childWidth;/**** 上下文*/private Context context;/**** 保存图片点的位置*/private List<LYJGesturePoint> list;/**** 创建view使其在ViewGroup之上。*/private LYJGestureView gestureDrawline;private int baseNum = 5;public LYJViewGroup(Context context) {super(context);this.context = context;this.list = new ArrayList<>();DisplayMetrics metric = new DisplayMetrics();((Activity) context).getWindowManager().getDefaultDisplay().getMetrics(metric);childWidth = metric.widthPixels / 3; // 屏幕宽度（像素）addChild();// 初始化一个可以画线的viewgestureDrawline = new LYJGestureView(context, list);gestureDrawline.setAnimationCallback(this);}public void setParentView(ViewGroup parent){// 得到屏幕的宽度DisplayMetrics metric = new DisplayMetrics();((Activity) context).getWindowManager().getDefaultDisplay().getMetrics(metric);int width = metric.widthPixels;LayoutParams layoutParams = new LayoutParams(width, width);this.setLayoutParams(layoutParams);gestureDrawline.setLayoutParams(layoutParams);parent.addView(this);parent.addView(gestureDrawline);}@Overrideprotected void onLayout(boolean changed, int l, int t, int r, int b) {for (int i = 0; i < getChildCount(); i++) {//第几行int rowspan = i / 3;//第几列int column = i % 3;android.view.View v = getChildAt(i);v.layout(column * childWidth + childWidth / baseNum, rowspan * childWidth + childWidth / baseNum,column * childWidth + childWidth - childWidth / baseNum, rowspan * childWidth + childWidth - childWidth / baseNum);}}@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {super.onMeasure(widthMeasureSpec, heightMeasureSpec);// 遍历设置每个子view的大小for (int i = 0; i < getChildCount(); i++) {View v = getChildAt(i);v.measure(widthMeasureSpec, heightMeasureSpec);}}private void addChild() {for (int i = 0; i < 9; i++) {ImageView image = new ImageView(context);image.setBackgroundResource(R.drawable.marker);this.addView(image);invalidate();// 第几行int rowspan = i / 3;// 第几列int column = i % 3;// 定义点的左上角与右下角的坐标int leftX = column * childWidth + childWidth / baseNum;int topY = rowspan * childWidth + childWidth / baseNum;int rightX = column * childWidth + childWidth - childWidth / baseNum;int bottomY = rowspan * childWidth + childWidth - childWidth / baseNum;LYJGesturePoint p = new LYJGesturePoint(leftX, topY, rightX,bottomY,i);this.list.add(p);}}@Overridepublic void startAnimationImage(int i) {Animation animation= AnimationUtils.loadAnimation(getContext(), R.anim.gridlayout_child_scale_anim);getChildAt(i).startAnimation(animation);}}

3.自定义点类

顾名思义，就是为了获取点的相关的属性，其中基础属性图片左上角坐标与右下角坐标，计算图片中心位置以便获取图片中心点。状态标记，表示该点是否绘制到图片。下面是其实体类：

public class LYJGesturePoint {private Point pointLeftTop;//左上角坐标private Point pointRightBottom;//右下角坐标private int centerX;//图片中心点X坐标private int centerY;//图片中心点Y坐标private int pointState;//是否点击了该图片private int num;public int getNum() {return num;}public int getPointState() {return pointState;}public void setPointState(int pointState) {this.pointState = pointState;}public Point getPointLeftTop() {return pointLeftTop;}public Point getPointRightBottom() {return pointRightBottom;}public LYJGesturePoint(int left,int top,int right,int bottom,int i){this.pointLeftTop=new Point(left,top);this.pointRightBottom=new Point(right,bottom);this.num=i;}public int getCenterX() {this.centerX=(this.pointLeftTop.x+this.pointRightBottom.x)/2;return centerX;}public int getCenterY() {this.centerY=(this.pointLeftTop.y+this.pointRightBottom.y)/2;return centerY;}}

4.自定义圆类

这个类较简单就三个属性而已（圆中心点坐标及半径），代码如下：

public class LYJCirclePoint {private int roundX;//圆中心点X坐标private int roundY;//圆中心点Y坐标private int radiu;//圆半径public int getRadiu() {return radiu;}public int getRoundX() {return roundX;}public int getRoundY() {return roundY;}public LYJCirclePoint(int roundX,int roundY,int radiu){this.roundX=roundX;this.roundY=roundY;this.radiu=radiu;}}

5.实现自定义绘制类View

代码如下：

public class LYJGestureView extends android.view.View {/**** 声明直线画笔*/private Paint paint;/**** 声明圆圈画笔*/private Paint circlePaint;/**** 画布*/private Canvas canvas;/**** 位图*/private Bitmap bitmap;/**** 装有各个view坐标的集合，用于判断点是否在其中*/private List<LYJGesturePoint> list;/**** 记录画过的线*/private List<Pair<LYJGesturePoint, LYJGesturePoint>> lineList;/**** 记录画过的圆*/private List<LYJCirclePoint> circlePoints;/*** 手指当前在哪个Point内*/private LYJGesturePoint currentPoint;/**** 手指按下动画*/private OnAnimationCallback animationCallback;public interface OnAnimationCallback{public void startAnimationImage(int i);}public void setAnimationCallback(OnAnimationCallback animationCallback) {this.animationCallback = animationCallback;}public LYJGestureView(Context context, List<LYJGesturePoint> list){super(context);Log.i(getClass().getName(), "GestureDrawline");paint = new Paint(Paint.DITHER_FLAG);// 创建一个画笔circlePaint=new Paint(Paint.DITHER_FLAG);DisplayMetrics metric = new DisplayMetrics();((Activity)context).getWindowManager().getDefaultDisplay().getMetrics(metric);Log.i(getClass().getName(), "widthPixels" + metric.widthPixels);Log.i(getClass().getName(), "heightPixels" + metric.heightPixels);bitmap = Bitmap.createBitmap(metric.widthPixels, metric.heightPixels, Bitmap.Config.ARGB_8888); // 设置位图的宽高canvas = new Canvas();canvas.setBitmap(bitmap);paint.setStyle(Paint.Style.STROKE);// 设置非填充paint.setStrokeWidth(20);// 笔宽20像素paint.setColor(Color.rgb(245, 142, 33));// 设置默认连线颜色paint.setAntiAlias(true);// 不显示锯齿circlePaint.setStyle(Paint.Style.FILL);circlePaint.setStrokeWidth(1);circlePaint.setAntiAlias(true);circlePaint.setColor(Color.rgb(245, 142, 33));this.list = list;this.lineList = new ArrayList<>();this.circlePoints=new ArrayList<>();}@Overridepublic boolean onTouchEvent(MotionEvent event) {switch (event.getAction()){case MotionEvent.ACTION_DOWN:// 判断当前点击的位置是处于哪个点之内currentPoint = getPointAt((int) event.getX(), (int) event.getY());if (currentPoint != null) {currentPoint.setPointState(Constants.POINT_STATE_SELECTED);this.animationCallback.startAnimationImage(currentPoint.getNum());canvas.drawCircle(currentPoint.getCenterX(), currentPoint.getCenterY(), 20, circlePaint);circlePoints.add(new LYJCirclePoint(currentPoint.getCenterX(),currentPoint.getCenterY(),20));}invalidate();break;case MotionEvent.ACTION_MOVE:clearScreenAndDrawList();// 得到当前移动位置是处于哪个点内LYJGesturePoint pointAt = getPointAt((int) event.getX(), (int) event.getY());if (currentPoint == null && pointAt == null) {//你把手指按在屏幕滑动，如果终点与起点都不图片那么返回return true;} else {// 代表用户的手指移动到了点上if (currentPoint == null) {// 先判断当前的point是不是为null// 如果为空，那么把手指移动到的点赋值给currentPointcurrentPoint = pointAt;// 把currentPoint这个点设置选中状态;currentPoint.setPointState(Constants.POINT_STATE_SELECTED);}}//如果移动到的点不为图片区域或者移动到自己的地方，或者该图片已经为选中状态，直接画直线就可以了if(pointAt == null || currentPoint.equals(pointAt) || Constants.POINT_STATE_SELECTED == pointAt.getPointState()){canvas.drawCircle(currentPoint.getCenterX(), currentPoint.getCenterY(), 20, circlePaint);circlePoints.add(new LYJCirclePoint(currentPoint.getCenterX(), currentPoint.getCenterY(), 20));canvas.drawLine(currentPoint.getCenterX(), currentPoint.getCenterY(), event.getX(), event.getY(), paint);}else{//其他情况画两点相连直线，并且保存绘制圆与直线，并调用按下图片的缩放动画canvas.drawCircle(pointAt.getCenterX(),pointAt.getCenterY(),20,circlePaint);circlePoints.add(new LYJCirclePoint(pointAt.getCenterX(), pointAt.getCenterY(), 20));this.animationCallback.startAnimationImage(pointAt.getNum());pointAt.setPointState(Constants.POINT_STATE_SELECTED);canvas.drawLine(currentPoint.getCenterX(), currentPoint.getCenterY(), pointAt.getCenterX(), pointAt.getCenterY(), paint);Pair<LYJGesturePoint, LYJGesturePoint> pair = new Pair<>(currentPoint, pointAt);lineList.add(pair);currentPoint=pointAt;//设置选中点为当前点。}invalidate();//重绘break;case MotionEvent.ACTION_UP:clearScreenAndDrawList();//防止多出一条没有终点的直线new Handler().postDelayed(new clearLineRunnable(), 1000);//1秒后清空绘制界面invalidate();//重绘break;default:break;}return true;}class clearLineRunnable implements Runnable {public void run() {// 清空保存点与圆的集合lineList.clear();circlePoints.clear();// 重新绘制界面clearScreenAndDrawList();for (LYJGesturePoint p : list) {//设置其为初始化不选中状态p.setPointState(Constants.POINT_STATE_NORMAL);}invalidate();}}/*** 通过点的位置去集合里面查找这个点是包含在哪个Point里面的** @param x* @param y* @return 如果没有找到，则返回null，代表用户当前移动的地方属于点与点之间*/private LYJGesturePoint getPointAt(int x, int y) {for (LYJGesturePoint point : list) {// 先判断点是否在图片的X坐标内int leftX = point.getPointLeftTop().x;int rightX = point.getPointRightBottom().x;if (!(x >= leftX && x < rightX)) {// 如果为假，则跳到下一个对比continue;}//在判断点是否在图片的Y坐标内int topY = point.getPointLeftTop().y;int bottomY = point.getPointRightBottom().y;if (!(y >= topY && y < bottomY)) {// 如果为假，则跳到下一个对比continue;}// 如果执行到这，那么说明当前点击的点的位置在遍历到点的位置这个地方return point;}return null;}/*** 清掉屏幕上所有的线，然后画出集合里面的线*/private void clearScreenAndDrawList() {canvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);for (Pair<LYJGesturePoint, LYJGesturePoint> pair : lineList) {canvas.drawLine(pair.first.getCenterX(), pair.first.getCenterY(),pair.second.getCenterX(), pair.second.getCenterY(), paint);// 画线}for(LYJCirclePoint lyjCirclePoint : circlePoints){canvas.drawCircle(lyjCirclePoint.getRoundX(),lyjCirclePoint.getRoundY(), lyjCirclePoint.getRadiu(),circlePaint);}}//绘制用bitmap创建出来的画布@Overrideprotected void onDraw(Canvas canvas) {canvas.drawBitmap(bitmap, 0, 0, null);}}

这样就可以得到如下界面效果(当然反编译百度钱包，并没有百度钱包中的图片，只好随便找了一张图片)：