fragment 中的 Android 自定义日历

Question

我正在尝试创建一个自定义日历，从这个例子开始 Here唯一的异常(exception)是我希望它在一个 fragment 中。但是我在这里遇到了一个空点错误:gridview.setAdapter(adapter); 适配器类、xml 和可绘制对象都是相同的。

package com.projectcaruso.naturalfamilyplaning;


import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.GregorianCalendar;
import java.util.Locale;
import android.os.Bundle;
import android.os.Handler;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.GridView;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.widget.Toast;


public class CalendarFragment extends Fragment {

public GregorianCalendar month, itemmonth;// calendar instances.

public CalendarAdapter adapter;// adapter instance
public Handler handler;// for grabbing some event values for showing the dot
                        // marker.
public ArrayList<String> items; // container to store calendar items which
                                // needs showing the event marker


    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }     

    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {     
        View view = inflater.inflate(R.layout.fragment_calendar, null);

        Locale.setDefault( Locale.US );
        month = (GregorianCalendar) GregorianCalendar.getInstance();
        itemmonth = (GregorianCalendar) month.clone();

        items = new ArrayList<String>();
        adapter = new CalendarAdapter(getActivity(), month);

        GridView gridview = (GridView) getActivity().findViewById(R.id.gridview);
        gridview.setAdapter(adapter);

        handler = new Handler();
        handler.post(calendarUpdater);

        TextView title = (TextView) getActivity().findViewById(R.id.title);
        title.setText(android.text.format.DateFormat.format("MMMM yyyy", month));

        RelativeLayout previous = (RelativeLayout) getActivity().findViewById(R.id.previous);

        previous.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                setPreviousMonth();
                refreshCalendar();
            }
        });

        RelativeLayout next = (RelativeLayout) getActivity().findViewById(R.id.next);
        next.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                setNextMonth();
                refreshCalendar();

            }
        });

        gridview.setOnItemClickListener(new OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent, View v,
                    int position, long id) {

                ((CalendarAdapter) parent.getAdapter()).setSelected(v);
                String selectedGridDate = CalendarAdapter.dayString
                        .get(position);
                String[] separatedTime = selectedGridDate.split("-");
                String gridvalueString = separatedTime[2].replaceFirst("^0*",
                        "");// taking last part of date. ie; 2 from 2012-12-02.
                int gridvalue = Integer.parseInt(gridvalueString);
                // navigate to next or previous month on clicking offdays.
                if ((gridvalue > 10) && (position < 8)) {
                    setPreviousMonth();
                    refreshCalendar();
                } else if ((gridvalue < 7) && (position > 28)) {
                    setNextMonth();
                    refreshCalendar();
                }
                ((CalendarAdapter) parent.getAdapter()).setSelected(v);

                showToast(selectedGridDate);

            }
        });
        return view;
    }

    protected void setNextMonth() {
        if (month.get(GregorianCalendar.MONTH) == month
                .getActualMaximum(GregorianCalendar.MONTH)) {
            month.set((month.get(GregorianCalendar.YEAR) + 1),
                    month.getActualMinimum(GregorianCalendar.MONTH), 1);
        } else {
            month.set(GregorianCalendar.MONTH,
                    month.get(GregorianCalendar.MONTH) + 1);
        }

    }

    protected void setPreviousMonth() {
        if (month.get(GregorianCalendar.MONTH) == month
                .getActualMinimum(GregorianCalendar.MONTH)) {
            month.set((month.get(GregorianCalendar.YEAR) - 1),
                    month.getActualMaximum(GregorianCalendar.MONTH), 1);
        } else {
            month.set(GregorianCalendar.MONTH,
                    month.get(GregorianCalendar.MONTH) - 1);
        }

    }

    protected void showToast(String string) {
        Toast.makeText(getActivity(), string, Toast.LENGTH_SHORT).show();

    }

    public void refreshCalendar() {
        TextView title = (TextView) getActivity().findViewById(R.id.title);

        adapter.refreshDays();
        adapter.notifyDataSetChanged();
        handler.post(calendarUpdater); // generate some calendar items

        title.setText(android.text.format.DateFormat.format("MMMM yyyy", month));
    }

    public Runnable calendarUpdater = new Runnable() {

        @Override
        public void run() {
            items.clear();

            // Print dates of the current week
            DateFormat df = new SimpleDateFormat("yyyy-MM-dd",Locale.US);
            String itemvalue;
            for (int i = 0; i < 7; i++) {
                itemvalue = df.format(itemmonth.getTime());
                itemmonth.add(GregorianCalendar.DATE, 1);
                items.add("2012-09-12");
                items.add("2012-10-07");
                items.add("2012-10-15");
                items.add("2012-10-20");
                items.add("2012-11-30");
                items.add("2012-11-28");
            }

            adapter.setItems(items);
            adapter.notifyDataSetChanged();
        }
    };
}

Answer 1

我猜 gridview 是空的。为什么不尝试更改此行....

   GridView gridview = (GridView) getActivity().findViewById(R.id.gridview);

有了这个...

   GridView gridview = (GridView) view.findViewById(R.id.gridview);

设置断点并查看 gridview 现在是否有值。