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view
gesturedrawline = 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);
}
@override
protected 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);
}
}
@override
protected 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);
}
}
@override
public 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<>();
}
@override
public 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currentpoint
currentpoint = 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
@override
protected 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)：