上来就干，是我一贯的作风！

先预览下效果图

未签到效果.png

已签到效果.png

分析控件结构：

从上到下依次是TextView→GridView→GridView

布局代码：

xmlns:android="http://schemas.android.com/apk/res/android"

android:orientation="vertical"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:background="@android:color/white">

android:id="@+id/tvYear"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:padding="10dp"

android:text="2017年7月"

android:gravity="center"

android:textColor="@android:color/white"

android:background="@color/colorAccent"/>

android:id="@+id/gvWeek"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:numColumns="7">

android:id="@+id/gvDate"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:numColumns="7">

1、tvYear负责显示年月。

2、gvWeek负责显示星期几

3、gvDate负责显示日历

把整体布局作为组合控件封装在SignDate类里面，SignDate主要代码如下：

public class SignDate extends LinearLayout {

private TextView tvYear;

private InnerGridView gvWeek;

private InnerGridView gvDate;

private AdapterDate adapterDate;

public SignDate(Context context) {

super(context);

init();

}

...

private void init(){

View view = View.inflate(getContext(),R.layout.layout_signdate,this);

tvYear = view.findViewById(R.id.tvYear);

gvWeek = view.findViewById(R.id.gvWeek);

gvDate = view.findViewById(R.id.gvDate);

tvYear.setText(DateUtil.getCurrentYearAndMonth());

gvWeek.setAdapter(new AdapterWeek(getContext()));

adapterDate = new AdapterDate(getContext());

gvDate.setAdapter(adapterDate);

}

/**

* 签到成功的回调

* @param onSignedSuccess

*/

public void setOnSignedSuccess(OnSignedSuccess onSignedSuccess){

adapterDate.setOnSignedSuccess(onSignedSuccess);

}

}

代码中AdapterWeek就是简单的设置星期几数据，这里不多介绍。

在AdapterDate中实现了本月天数计算，开始天数应该显示在星期几的位置，和点击签到实现签到效果，代码如下：

public class AdapterDate extends BaseAdapter {

private Context context;

private List days = new ArrayList<>();

//日历数据

private List status = new ArrayList<>();

//签到状态，实际应用中初始化签到状态可通过该字段传递

private OnSignedSuccess onSignedSuccess;

//签到成功的回调方法，相应的可自行添加签到失败时的回调方法

public AdapterDate(Context context) {

this.context = context;

int maxDay = DateUtil.getCurrentMonthLastDay();//获取当月天数

for (int i = 0; i < DateUtil.getFirstDayOfMonth() - 1; i++) {

//DateUtil.getFirstDayOfMonth()获取当月第一天是星期几，星期日是第一天，依次类推

days.add(0);

//0代表需要隐藏的item

status.add(false);

//false代表为签到状态

}

for (int i = 0; i < maxDay; i++) {

days.add(i+1);

//初始化日历数据

status.add(false);

//初始化日历签到状态

}

}

@Override

public int getCount() {

return days.size();

}

@Override

public Object getItem(int i) {

return days.get(i);

}

@Override

public long getItemId(int i) {

return i;

}

@Override

public View getView(final int i, View view, ViewGroup viewGroup) {

ViewHolder viewHolder;

if(view==null){

view = LayoutInflater.from(context).inflate(R.layout.item_gv,null);

viewHolder = new ViewHolder();

view.setTag(viewHolder);

}else{

viewHolder = (ViewHolder) view.getTag();

}

viewHolder.tv = view.findViewById(R.id.tvWeek);

viewHolder.rlItem = view.findViewById(R.id.rlItem);

viewHolder.ivStatus = view.findViewById(R.id.ivStatus);

viewHolder.tv.setText(days.get(i)+"");

if(days.get(i)==0){

viewHolder.rlItem.setVisibility(View.GONE);

}

if(status.get(i)){

viewHolder.tv.setTextColor(Color.parseColor("#FD0000"));

viewHolder.ivStatus.setVisibility(View.VISIBLE);

}else{

viewHolder.tv.setTextColor(Color.parseColor("#666666"));

viewHolder.ivStatus.setVisibility(View.GONE);

}

view.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View view) {

if(status.get(i)){

Toast.makeText(context,"Already sign in!",Toast.LENGTH_SHORT).show();

}else{

Toast.makeText(context,"Sign in success!",Toast.LENGTH_SHORT).show();

status.set(i,true);

notifyDataSetChanged();

if(onSignedSuccess!=null){

onSignedSuccess.OnSignedSuccess();

}

}

}

});

return view;

}

class ViewHolder{

RelativeLayout rlItem;

TextView tv;

ImageView ivStatus;

}

public void setOnSignedSuccess(OnSignedSuccess onSignedSuccess){

this.onSignedSuccess = onSignedSuccess;

}

}

代码实在简单，没有什么技术上的难点，初始化数据、签到失败回调、界面效果等一些功能，大家可以自行补充。

工程源码地址：https://github.com/StormFeng/SignDate