MyNotePad

1.0 Version

运行环境

AndroidStudio 3.3.1
JDK 1.8
minSdkVersion 21 TargetSdkVersion 28
模拟机API 23

时间戳

代码分析

（1）在布局文件中增加一个TextView来显示时间戳

（2）数据库中已有文本创建时间和修改时间连个字段，在NodeEditor.java中,找到updateNode()这个函数，选取修改时间这一字段，并将其格式化存入数据库

Date nowTime = new Date(System.currentTimeMillis());SimpleDateFormat sdFormatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");String retStrFormatNowDate = sdFormatter.format(nowTime);

values.put(NotePad.Notes.COLUMN_NAME_MODIFICATION_DATE, retStrFormatNowDate);

（3）在NoteList.java的PROJECTION数组中增加该字段的描述，并在SimpleCursorAdapter中的参数viewsIDs和dataColumns增加子段描述，以达到将其读出和显示的目的

//The columns needed by the cursor adapterprivate static final String[] PROJECTION = new String[] {            NotePad.Notes._ID, // 0            NotePad.Notes.COLUMN_NAME_TITLE, // 1            NotePad.Notes.COLUMN_NAME_MODIFICATION_DATE,    };// The names of the cursor columns to display in the view, initialized to the title columnprivate String[] dataColumns = { NotePad.Notes.COLUMN_NAME_TITLE ,NotePad.Notes.COLUMN_NAME_MODIFICATION_DATE} ;// The view IDs that will display the cursor columns, initialized to the TextView inprivate int[] viewIDs = { R.id.text1,R.id.text2 };

效果

搜索笔记以title为关键字段

代码分析

（1）在NodeList.java的布局文件中新增SearchView控件（备注：引用的是support.v7的包，如未找到，需在build.gradle(Module.app）中添加依赖

（2）在NodeList.java中创建一个函数专门来配置SeachView，实现查询的基本思想是新创建一个Cursor来通过SeacrhView搜索的字段在数据库中进行模糊搜索从而装配数据，并在ListView中即时显示，无需点击搜索按键，最后在onCreate()中调用

private void SearchView(){        searchView=findViewById(R.id.sv);        // a display model        searchView.onActionViewExpanded();        //default display        searchView.setQueryHint("搜索笔记");        //display submit button        searchView.setSubmitButtonEnabled(true);        //implement SearchView TextListener        searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {            // when text has been submitted            @Override            public boolean onQueryTextSubmit(String s) {                return false;            }            // when text is changing            @Override            public boolean onQueryTextChange(String s) {                if(!s.equals("")){                    String selection=NotePad.Notes.COLUMN_NAME_TITLE+" GLOB '*"+s+"*'";//query selection condition                    updatecursor = getContentResolver().query(                            getIntent().getData(),            // Use the default content URI for the provider.                            PROJECTION,                       // Return the note ID and title for each note.                            selection,                             // No where clause, return all records.                            null,                             // No where clause, therefore no where column values.                            NotePad.Notes.DEFAULT_SORT_ORDER  // Use the default sort order.                    );                }               else {                    updatecursor = getContentResolver().query(                            getIntent().getData(),            // Use the default content URI for the provider.                            PROJECTION,                       // Return the note ID and title for each note.                            null,                             // No where clause, return all records.                            null,                             // No where clause, therefore no where column values.                            NotePad.Notes.DEFAULT_SORT_ORDER  // Use the default sort order.                    );                }                // change adapter from SimpleCursorAdapter cursor                adapter.swapCursor(updatecursor);               // adapter.notifyDataSetChanged();                return false;            }        });    }

效果

修改背景色及字体颜色

代码分析

（1）在OptionMenu中添加修改颜色这一选项，并划分为两类，修改背景颜色和修改字体颜色

（2）采用AlertDialog来实现界面交互效果，并采用自定义布局定义UI界面，因为两种修改颜色调用的是同一个函数showColor（），因此定义一个boolean变量flag来判断

private void showColor(){        AlertDialog alertDialog=new AlertDialog.Builder(this).setTitle("请选择颜色").                setIcon(R.mipmap.ic_launcher).setView(R.layout.color_layout)                .setPositiveButton("确定", new DialogInterface.OnClickListener() {                    @Override                    public void onClick(DialogInterface dialog, int which) {                        dialog.dismiss();                    }                }).create();        alertDialog.show();    }

AlertDialog布局文件

布局文件按钮的点击事件

public void onClick(View v) {        switch (v.getId()){            case R.id.orange:                if(isFlag){                    mText.setBackgroundColor(Color.parseColor("#FF8C00"));                    colorBack="#FF8C00";                }else{                    mText.setTextColor(Color.parseColor("#FF8C00"));                    colorText="#FF8C00";                }                break;            case R.id.chocolate:                if(isFlag){                    mText.setBackgroundColor(Color.parseColor("#D2691E"));                    colorBack="#D2691E";                }else{                    mText.setTextColor(Color.parseColor("#D2691E"));                    colorText="#D2691E";                }                break;            case R.id.aqua:                if(isFlag){                    mText.setBackgroundColor(Color.parseColor("#00FFFF"));                    colorBack="#00FFFF";                }else{                    mText.setTextColor(Color.parseColor("#00FFFF"));                    colorText="#00FFFF";                }                break;            case R.id.gray:                if(isFlag){                    mText.setBackgroundColor(Color.parseColor("#696969"));                    colorBack="#696969";                }else{                    mText.setTextColor(Color.parseColor("#696969"));                    colorText="#696969";                }                break;            case R.id.pink:                if(isFlag){                    mText.setBackgroundColor(Color.parseColor("#D81B60"));                    colorBack="#D81B60";                }else{                    mText.setTextColor(Color.parseColor("#D81B60"));                    colorText="#D81B60";                }                break;            case R.id.green:                if(isFlag){                    mText.setBackgroundColor(Color.parseColor("#00FF7F"));                    colorBack="#00FF7F";                }else{                    mText.setTextColor(Color.parseColor("#00FF7F"));                    colorText="#00FF7F";                }                break;        }    }

（3）在onOptionItemSelected（）中添加点击事件

case R.id.background_color:    isFlag=true;    showColor();    break;case R.id.text_color:    isFlag=false;    showColor();    break;

（4）点击保存之后将颜色的16进制保存到数据库,也是通过updateNote()函数，具体实现与时间戳功能类似，这里说明一下数据库新增字段的实现

1.在NotePad.java中的内部类Notes添加契约

/** NoteEditor.java EditText setBackGroundColor* */public static final String COLUMN_BACKGROUND_COLOR="bColor";/* * NoteEditor.java EditText setTextColor * */public static final String COLUMN_TEXT_COLOR="tColor";

2.在NotePadProvider.java的静态构造块往sNotesProjectionMap添加相应的键值对

//Maps "bColor" to "bColor"sNotesProjectionMap.put(        NotePad.Notes.COLUMN_BACKGROUND_COLOR,        NotePad.Notes.COLUMN_BACKGROUND_COLOR);//Maps "tColor" to "tColor"sNotesProjectionMap.put(        NotePad.Notes.COLUMN_TEXT_COLOR,        NotePad.Notes.COLUMN_TEXT_COLOR);

备注：如果已经在手机中安装app之后要新增或删减字段，需要在onUpgrade（）中更换版本号，或者卸载重装。

效果

添加标签以将文本分类

代码分析

（1）在数据库中添加标签字段，与修改颜色功能类似，不作相应代码显示
（2）在NodeEditor.java布局文件中添加Button控件，点击弹出AlertDialog显示类别选项，设置按钮文本

//tag selection definedprivate final String items[]={"Default","Travel","Work","Study","Life"};

public void tagSelect(View v){        AlertDialog.Builder tagbuilder;        AlertDialog alertDialog;        tagbuilder=new AlertDialog.Builder(this);        tagbuilder.setTitle("Tag Selection:");        tagbuilder.setIcon(R.mipmap.ic_launcher);        tagbuilder.setSingleChoiceItems(items, checkItem, new DialogInterface.OnClickListener() {            @Override            public void onClick(DialogInterface dialog, int which) {                checkItem=which;                button.setText(items[checkItem]);            }        });        tagbuilder.setPositiveButton("确定", new DialogInterface.OnClickListener() {            @Override            public void onClick(DialogInterface dialog, int which) {                dialog.dismiss();            }        });        alertDialog=tagbuilder.create();        alertDialog.show();    }

（3）点击保存之后会将按钮文本保存到数据库，与时间戳功能类似，不再作具体演示
（4）在NoteList.java添加抽屉布局，以显示侧滑菜单栏的效果

1.在AndroidManifest.xml中更改主题，禁用ActionBar，查看引用，在styles.xml中进行修改

android:theme="@style/AppTheme"

style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar"

2.在布局文件中使用DrawerLayout布局和toolbar，还有NavigationView，与之前同理，导入的分别是v4和v7的包，如果没有，需要添加依赖（注：CoordinatorLayout是之前想做一个浮动布局加的，但后来放弃了，所以这个布局是可以删除的，只要修改号里面控件的width和height就可以）

3.NavigationView的菜单编写

<?xml version="1.0" encoding="utf-8"?>                                                                                                                                                                                                                                                                                                

（3）编写toolbar的监听事件和NavigationView的监听事件
1.toolbar

setSupportActionBar(toolbar); //set support toolbar in this Activitytoolbar.setNavigationOnClickListener(new View.OnClickListener() {    @Override    public void onClick(View v) {        drawerLayout.openDrawer(Gravity.START);// set from left open NavigationView Menu    }});

2.NavigationView

navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {            @Override            public boolean onNavigationItemSelected(@NonNull MenuItem menuItem) {                switch (menuItem.getItemId()){                    case R.id.notepad:                        tagCursor = getContentResolver().query(                                getIntent().getData(),            // Use the default content URI for the provider.                                PROJECTION,                       // Return the note ID and title for each note.                                null,                             // No where clause, return all records.                                null,                             // No where clause, therefore no where column values.                                NotePad.Notes.DEFAULT_SORT_ORDER  // Use the default sort order.                        );                        adapter.swapCursor(tagCursor);//swap cursor from SimpleCursorAdapter                        toolbar.setTitle("MyNotePad");                        drawerLayout.closeDrawer(navigationView);//close NavigationView menu                        break;                    case R.id.travel:                        tagSelection=NotePad.Notes.COLUMN_TAG_SELECTION_INDEX+" = 'Travel'";                        tagCursor = getContentResolver().query(                                getIntent().getData(),            // Use the default content URI for the provider.                                PROJECTION,                       // Return the note ID and title for each note.                                tagSelection,                             // No where clause, return all records.                                null,                             // No where clause, therefore no where column values.                                NotePad.Notes.DEFAULT_SORT_ORDER  // Use the default sort order.                        );                        adapter.swapCursor(tagCursor);//swap cursor from SimpleCursorAdapter                        toolbar.setTitle("Travel");                        drawerLayout.closeDrawer(navigationView);//close NavigationView menu                        break;                    case R.id.work:                        tagSelection=NotePad.Notes.COLUMN_TAG_SELECTION_INDEX+" = 'Work'";                        tagCursor = getContentResolver().query(                                getIntent().getData(),            // Use the default content URI for the provider.                                PROJECTION,                       // Return the note ID and title for each note.                                tagSelection,                             // No where clause, return all records.                                null,                             // No where clause, therefore no where column values.                                NotePad.Notes.DEFAULT_SORT_ORDER  // Use the default sort order.                        );                        adapter.swapCursor(tagCursor);//swap cursor from SimpleCursorAdapter                        toolbar.setTitle("Work");                        drawerLayout.closeDrawer(navigationView);//close NavigationView menu                        break;                    case R.id.study:                        tagSelection=NotePad.Notes.COLUMN_TAG_SELECTION_INDEX+" = 'Study'";                        tagCursor = getContentResolver().query(                                getIntent().getData(),            // Use the default content URI for the provider.                                PROJECTION,                       // Return the note ID and title for each note.                                tagSelection,                             // No where clause, return all records.                                null,                             // No where clause, therefore no where column values.                                NotePad.Notes.DEFAULT_SORT_ORDER  // Use the default sort order.                        );                        adapter.swapCursor(tagCursor);//swap cursor from SimpleCursorAdapter                        toolbar.setTitle("Study");                        drawerLayout.closeDrawer(navigationView);//close NavigationView menu                        break;                    case R.id.life:                        tagSelection=NotePad.Notes.COLUMN_TAG_SELECTION_INDEX+" = 'Life'";                        tagCursor = getContentResolver().query(                                getIntent().getData(),            // Use the default content URI for the provider.                                PROJECTION,                       // Return the note ID and title for each note.                                tagSelection,                             // No where clause, return all records.                                null,                             // No where clause, therefore no where column values.                                NotePad.Notes.DEFAULT_SORT_ORDER  // Use the default sort order.                        );                        adapter.swapCursor(tagCursor);//swap cursor from SimpleCursorAdapter                        toolbar.setTitle("Life");                        drawerLayout.closeDrawer(navigationView);//close NavigationView menu                        break;                    case R.id.def:                        tagSelection=NotePad.Notes.COLUMN_TAG_SELECTION_INDEX+" = 'Default'";                        tagCursor = getContentResolver().query(                                getIntent().getData(),            // Use the default content URI for the provider.                                PROJECTION,                       // Return the note ID and title for each note.                                tagSelection,                             // No where clause, return all records.                                null,                             // No where clause, therefore no where column values.                                NotePad.Notes.DEFAULT_SORT_ORDER  // Use the default sort order.                        );                        adapter.swapCursor(tagCursor);//swap cursor from SimpleCursorAdapter                        toolbar.setTitle("Default");                        drawerLayout.closeDrawer(navigationView);//close NavigationView menu                        break;                }                return true;            }        });

效果

在文本中插入图片

代码分析

（1）在NodeEditor.java的optionmenu中添加选项

（2）拍照要在AndroidManifest.xml中设置权限，API23以上还要在代码中设置动态权限，API28以上权限设置更为严格，本功能并不适用。而从图库中选取照片权限要求较低.

//从相册取图片public void getPhoto() {        Intent intent = new Intent();        intent.setType("image/*");        intent.setAction(Intent.ACTION_OPEN_DOCUMENT);        startActivityForResult(intent, PHOTO_FROM_GALLERY);}//拍照取照片public void takeCamera() {        if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {            ActivityCompat.requestPermissions( this, new String[] { Manifest.permission.CAMERA }, PHOTO_FROM_CAMERA);        }        else {            File file=new File(Environment.getExternalStorageDirectory(),System.currentTimeMillis()+".jpg");            try {                if(file.exists()){                    file.delete();                }                file.createNewFile();            }catch (IOException e){                e.printStackTrace();            }            imageUri=Uri.fromFile(file);            Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);            intent.putExtra(MediaStore.EXTRA_OUTPUT,imageUri);            startActivityForResult(intent, PHOTO_FROM_CAMERA);        }}

（3）编写onActivityResult定义返回动作

    @Override    protected void onActivityResult(int requestCode, int resultCode, Intent data) {        ContentResolver resolver = getContentResolver();        super.onActivityResult(requestCode, resultCode, data);        //第一层switch        switch (requestCode) {            case PHOTO_FROM_GALLERY:                //第二层switch                switch (resultCode) {                    case RESULT_OK:                        if (data != null) {                            Uri uri = data.getData();//获取Intent uri                            Bitmap bitmap = null;                            //判断该路径是否存在                            try {                                Bitmap originalBitmap = BitmapFactory.decodeStream(resolver.openInputStream(uri));                                bitmap = resizeImage(originalBitmap, 200, 200);//图片缩放                            } catch (FileNotFoundException e) {                                e.printStackTrace();                            }                            if(bitmap != null){//如果图片存在                                //将选择的图片追加到EditText中光标所在位置                                int index = mText.getSelectionStart(); //获取光标所在位置                                Editable edit_text = mText.getEditableText();//编辑文本框                                if(index <0 || index >= edit_text.length()){                                    edit_text.append(uri.toString());                                    updateNoteText(mText.getText().toString());//更新到数据库                                }else{                                    edit_text.insert(index,uri.toString());                                    updateNoteText(mText.getText().toString());//更新到数据库                                }                            }else{                                Toast.makeText(NoteEditor.this, "获取图片失败", Toast.LENGTH_SHORT).show();                            }                        }                        break;                    case RESULT_CANCELED:                        break;                }                break;            case PHOTO_FROM_CAMERA:                if (resultCode == RESULT_OK) {                    Bitmap originalBitmap1=null;                    //判断图片是否存在                    try{                        originalBitmap1=BitmapFactory.decodeStream(getContentResolver().openInputStream(imageUri));                    }catch (FileNotFoundException e){                        e.printStackTrace();                    }                    if(originalBitmap1 != null){//如果图片存在保存URI                        //将选择的图片追加到EditText中光标所在位置                        int index = mText.getSelectionStart(); //获取光标所在位置                        Editable edit_text = mText.getEditableText();//编辑文本框                        if(index <0 || index >= edit_text.length()){                            edit_text.append(imageUri.toString());                            updateNoteText(mText.getText().toString());//更新到数据库                        }else{                            edit_text.insert(index, imageUri.toString());                            updateNoteText(mText.getText().toString());//更新到数据库                        }                    }else{                        Toast.makeText(NoteEditor.this, "获取图片失败", Toast.LENGTH_SHORT).show();                    }                } else {                    Log.e("result", "is not ok" + resultCode);                }                break;            default:                break;        }    }

（4）定义两个正则表达式，提取文本的图片路径，用SpannableString进行图片文字替换，从而实现图片的插入

private static final String regex="content://com.android.providers.media.documents/"    +"document/image%\\w{4}";private static final String reg="file:///storage/emulated/0/\\d+.jpg";

onResumn（）和cancelNote（）中编写

    int colNoteIndex = mCursor.getColumnIndex(NotePad.Notes.COLUMN_NAME_NOTE);//提取数据库中的文本    String note = mCursor.getString(colNoteIndex);    ArrayList contentList=new ArrayList<>();//存放图片路径    ArrayList startList=new ArrayList<>();//存放图片路径起点位置    ArrayList endList=new ArrayList<>();//存放图片路径终点位置    Pattern p=Pattern.compile(regex);    Matcher m=p.matcher(note);    //当匹配到图库相应资源地址，将对应信息存入List    while(m.find()){        contentList.add(m.group());        startList.add(m.start());        endList.add(m.end());        flag=true;    }    p=Pattern.compile(reg);    m=p.matcher(note);    //当匹配到拍照的图片相应资源地址，将对应信息存入List    while(m.find()){        contentList.add(m.group());        startList.add(m.start());        endList.add(m.end());        flag=true;    }    //判断文本中是否有图片资源地址    if(!flag){        mText.setText(note);    }else{        pushPicture(note,contentList,startList,endList);    }

图片处理

private void pushPicture(String note,ArrayList contentList,ArrayList startList,ArrayList endList) {        //创建一个SpannableString对象，以便插入用ImageSpan对象封装的图像        SpannableString spannableString = new SpannableString(note);        for(int i=0;i

private void createDateDialog(){        final Calendar calendar=Calendar.getInstance();        DatePickerDialog dialog = new DatePickerDialog(this, AlertDialog.THEME_HOLO_DARK,                new DatePickerDialog.OnDateSetListener() {                    @Override                    public void onDateSet(DatePicker view, int year, int month, int dayOfMonth) {                        date=year+"-"+(month+1)+"-"+dayOfMonth;                        if(time!=null){                            dateButton.setText(date+time);                        }else{                            String text=calendar.get(Calendar.HOUR_OF_DAY)+":"+(calendar.get(Calendar.MINUTE)+5);                            time=" "+text;//如果时间未指定，则默认为当前时间的5分钟后提醒                            dateButton.setText(date+" "+text);                        }                        dateButton.setVisibility(View.VISIBLE);                    }                },                calendar.get(Calendar.YEAR),                calendar.get(Calendar.MONTH),                calendar.get(Calendar.DAY_OF_MONTH));        dialog.getDatePicker().setMinDate(System.currentTimeMillis()-1000);//选择以当前时间开始，避免无效时间的选择        dialog.setTitle("选择日期：");        dialog.show();    }

private void createTimeDialog(){        final Calendar calendar=Calendar.getInstance();        TimePickerDialog dialog=new TimePickerDialog(this, AlertDialog.THEME_HOLO_DARK,new TimePickerDialog.OnTimeSetListener() {            @Override            public void onTimeSet(TimePicker view, int hourOfDay, int minute) {                String text=calendar.get(Calendar.YEAR)+"-"+(calendar.get(Calendar.MONTH)+1)+"-"+calendar.get(Calendar.DAY_OF_MONTH);                /*                * 判断时间的选择是否为无效时间，在当前的时间之前                * */                if(text.equals(date)||date==null){                    if(hourOfDay<=calendar.get(Calendar.HOUR_OF_DAY))                        if(minute-5<=calendar.get(Calendar.MINUTE)){                            //为无效时间的话就将时间设为五分钟之后                            time=" "+calendar.get(Calendar.HOUR_OF_DAY)+":"+(calendar.get(Calendar.MINUTE)+5);                        }                        else{                            time=" "+calendar.get(Calendar.HOUR_OF_DAY)+":"+minute;                        }                    else{                        time=" "+hourOfDay+":"+minute;                    }                }else{                    time=" "+hourOfDay+":"+minute;                }                if(date!=null){                    dateButton.setText(date+time);                }else{                    date=text;                    dateButton.setText(text+time);                }                dateButton.setVisibility(View.VISIBLE);            }        },                calendar.get(Calendar.HOUR_OF_DAY),                calendar.get(Calendar.MINUTE), true);        dialog.setTitle("选择时间：");        dialog.show();    }

private void notifyMessage(){        if(time!=null&&date!=null){            SimpleDateFormat simpleDateFormat=new SimpleDateFormat("yyyy-MM-dd HH:mm");            long t=System.currentTimeMillis()+5000;            try {                t=simpleDateFormat.parse(date+time).getTime();            } catch (Exception e) {                // TODO: handle exception                e.printStackTrace();            }            //是Intent跳转到指定的广播处理            Intent intent=new Intent(NoteEditor.this, RemindActionBroadcast.class);            /*            * 把文本的内容和标题存入Intent            * */            intent.putExtra("title",mCursor.getString(mCursor.getColumnIndex(NotePad.Notes.COLUMN_NAME_TITLE)));            intent.putExtra("context",mCursor.getString(mCursor.getColumnIndex(NotePad.Notes.COLUMN_NAME_NOTE)));            //将requestCode设为每个文本的ID以实现能够发送不同的信息，不会被覆盖            PendingIntent pendingIntent=PendingIntent.getBroadcast(NoteEditor.this,mCursor.getInt(mCursor.getColumnIndex(NotePad.Notes._ID)),intent,PendingIntent.FLAG_UPDATE_CURRENT);            Calendar calendar=Calendar.getInstance();            calendar.setTimeInMillis(System.currentTimeMillis());            calendar.add(Calendar.SECOND,(int)((t-System.currentTimeMillis())/1000));            //使用AlarmManager实现定时功能            AlarmManager alarmManager=(AlarmManager)getSystemService(ALARM_SERVICE);            alarmManager.set(AlarmManager.RTC_WAKEUP,calendar.getTimeInMillis(),pendingIntent);        }    }

public class RemindActionBroadcast extends BroadcastReceiver {    public static int id=0;    @Override    public void onReceive(Context context, Intent intent) {        PendingIntent pendingIntent=PendingIntent.getActivity(context,0,intent,0);        NotificationManager notificationManager=(NotificationManager)context.getSystemService(context.NOTIFICATION_SERVICE);        Notification.Builder mbuilder=new Notification.Builder(context);        mbuilder.setContentTitle(intent.getStringExtra("title"));//设置通知栏标题        mbuilder.setContentText(intent.getStringExtra("context"));//设置通知栏内容        mbuilder.setSmallIcon(R.mipmap.ic_launcher);//设置小图标        mbuilder.setLargeIcon(BitmapFactory.decodeResource(context.getResources(),R.mipmap.ic_launcher));//设置大图标        mbuilder.setContentIntent(pendingIntent);//设置点击跳转的Intent，因为没有设置uri，所以跳转为空        mbuilder.setAutoCancel(true);//点击之后消失        Notification notification=mbuilder.build();        notificationManager.notify(id++,notification);//能够传送多条消息    }}

public void dateClick(View view){        AlertDialog.Builder builder=new AlertDialog.Builder(this);        builder.setMessage("请确认是否删除提醒时间：").setPositiveButton("确认", new DialogInterface.OnClickListener() {            @Override            public void onClick(DialogInterface dialog, int which) {                date=null;                time=null;                dateButton.setVisibility(View.GONE);                dialog.dismiss();            }        }).setNegativeButton("取消", new DialogInterface.OnClickListener() {            @Override            public void onClick(DialogInterface dialog, int which) {                dialog.dismiss();            }        });        builder.create().show();    }