ListView添加值重复

最新推荐文章于 2019-10-07 09:07:43 发布

chanqi2862

最新推荐文章于 2019-10-07 09:07:43 发布

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文章标签：移动开发 java

本文链接：https://blog.youkuaiyun.com/chanqi2862/article/details/53975185

本文介绍了一个关于ListView在点击按钮后重复添加项的问题，并提供了解决方案。涉及到Android开发中的ListView适配器更新机制和数据存储方式。

一个LinearLayout的布局(api 19),一个ListView,通过按钮往里面添加值,但是重复.求解决办法,

AlarmView.java:







import android.app.AlarmManager;

import android.app.AlertDialog;

import android.app.PendingIntent;

import android.app.TimePickerDialog;

import android.content.Context;

import android.content.DialogInterface;

import android.content.Intent;

import android.content.SharedPreferences;

import android.util.AttributeSet;

import android.view.View;

import android.widget.*;

//import com.jikexueyuan.xlclock.app.AlarmReceiver;//忽略这个类.

import com.jikexueyuan.xlclock.app.R;



import java.util.Calendar;





public class AlarmView extends LinearLayout {



    public AlarmView(Context context, AttributeSet attrs) {

        super(context, attrs);

        init();

    }



    /*public AlarmView(Context context, AttributeSet attrs, int defStyleAttr) {

        super(context, attrs, defStyleAttr);

        init();

    }*/



    public AlarmView(Context context) {

        super(context);

        init();

    }



    private void init() {

        alarmManager = (AlarmManager) getContext().getSystemService(Context.ALARM_SERVICE);

    }





    @Override

    protected void onFinishInflate() {

        super.onFinishInflate();

        btnAddAlarm = (Button) findViewById(R.id.btnAddAlarm);

        lvAlarmList = (ListView) findViewById(R.id.lvAlarmList);



        adapter = new ArrayAdapter<AlarmData>(getContext(), android.R.layout.simple_list_item_1);

        lvAlarmList.setAdapter(adapter);

        readSavedAlarm();



        btnAddAlarm.setOnClickListener(new OnClickListener() {

            @Override

            public void onClick(View v) {

                addAlarm();

            }

        });



        lvAlarmList.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {

            @Override

            public boolean onItemLongClick(AdapterView<?> parent, View view, final int position, long id) {

                new AlertDialog.Builder(getContext()).setTitle("操作选项")

                        .setItems(new CharSequence[]{"刪除"}, new DialogInterface.OnClickListener() {

                            @Override

                            public void onClick(DialogInterface dialog, int which) {

                                switch (which) {

                                    case 0:

                                        //刪除.

                                        deleteAlarm(position);

                                        break;

                                }

                            }

                        }).setNegativeButton("取消", null).show();



                return true;

            }

        });



    }





    private void deleteAlarm(int position) {

        AlarmData ad = adapter.getItem(position);

        adapter.remove(ad);

        saveAlarmList();

    }



    private void addAlarm() {



        Calendar c = Calendar.getInstance();

        new TimePickerDialog(getContext(), new TimePickerDialog.OnTimeSetListener() {

            @Override

            public void onTimeSet(TimePicker view, int hourOfDay, int minute) {

                Calendar calendar = Calendar.getInstance();

                calendar.set(Calendar.HOUR_OF_DAY, hourOfDay);

                calendar.set(Calendar.MINUTE, minute);

                calendar.set(Calendar.SECOND, 0);

                calendar.set(Calendar.MILLISECOND, 0);

                Calendar currentTime = Calendar.getInstance();

                if (calendar.getTimeInMillis() <= currentTime.getTimeInMillis()) {

                    calendar.setTimeInMillis(calendar.getTimeInMillis() + 24 * 60 * 60 * 1000);

                }

                AlarmData ad = new AlarmData(calendar.getTimeInMillis());

                adapter.add(ad);

                /*alarmManager.setRepeating(AlarmManager.RTC_WAKEUP,ad.getTime(), 3 * 60 * 1000, PendingIntent.getBroadcast(getContext(), ad.getId(), new Intent(getContext(), AlarmReceiver.class), 0));*/

                saveAlarmList();



            }

        }, c.get(Calendar.HOUR_OF_DAY), c.get(Calendar.MINUTE), true).show();

    }





    private void saveAlarmList() {

        SharedPreferences.Editor et = getContext().getSharedPreferences(

                AlarmView.class.getName(), Context.MODE_PRIVATE

        ).edit();

        StringBuffer sur = new StringBuffer();

        for (int i = 0; i < adapter.getCount(); i++) {

            sur.append(adapter.getItem(i).getTime()).append(",");

        }

        if (sur.length() > 1) {

            String content = sur.substring(0, sur.length() - 1);

            et.putString(KEY_ALARM_LIST, content);

        } else {

            et.putString(KEY_ALARM_LIST, null);

        }

        et.commit();

    }





    private void readSavedAlarm() {

        SharedPreferences sp = getContext().getSharedPreferences(

                AlarmView.class.getName(), Context.MODE_PRIVATE

        );

        String content = sp.getString(KEY_ALARM_LIST, null);

        if (content != null) {

            String[] timeStrings = content.split(",");

            for (String str : timeStrings) {

                adapter.add(new AlarmData(Long.parseLong(str)));

            }

        }



    }





    private Button btnAddAlarm;

    private ListView lvAlarmList;

    private static final String KEY_ALARM_LIST = "alarmlist";

    private ArrayAdapter<AlarmData> adapter=null;

    private AlarmManager alarmManager;





    private static class AlarmData {

        public AlarmData(long time) {

            this.time = time;

            date = Calendar.getInstance();

            date.setTimeInMillis(time);



            timeLabel = String.format("%d-%d %d:%d",

                    date.get(Calendar.MONTH) + 1,

                    date.get(Calendar.DAY_OF_MONTH),

                    date.get(Calendar.HOUR_OF_DAY),

                    date.get(Calendar.MINUTE));

        }



        private long time = 0;

        private String timeLabel = "";

        private Calendar date;



        @Override

        public String toString() {

            return getTimeLabel();

        }



        public long getTime() {

            return time;

        }



        public String getTimeLabel() {

            return timeLabel;

        }



        public int getId() {

            return (int) (getTime() / 1000 / 60);

        }

    }

}

布局文件:



<com.jikexueyuan.xlclock.app.view.AlarmView

                        android:id="@+id/tabAlarm"

                        android:layout_width="match_parent"

                        android:layout_height="match_parent"

                        android:orientation="vertical"

                        >



                    <ListView

                            android:id="@+id/lvAlarmList"

                            android:layout_width="fill_parent"

                            android:layout_height="0dp"

                            android:layout_weight="1"

                            />

                    <Button

                            android:id="@+id/btnAddAlarm"

                            android:text="@string/AddAlarm"

                            android:layout_width="fill_parent"

                            android:layout_height="wrap_content"

                            />



                </com.jikexueyuan.xlclock.app.view.AlarmView>