編輯:關於Android編程
在安卓開發中,會碰到選開始日期和結束日期的問題。特別是在使用Pad時,如果彈出一個Dialog,能夠同時選擇開始日期和結束日期,那將是極好的。我在開發中在DatePickerDialog的基礎上做了修改,實現了這種Dialog。效果如下:
具體實現方法為:
先新建一個安卓項目DoubleDatePicker,在res/layout文件夾下新建date_picker_dialog.xml,內容如下:
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="wrap_content" android:layout_height="wrap_content" android:gravity="center_horizontal" android:orientation="horizontal" android:paddingTop="10dp" > <LinearLayout android:layout_width="wrap_content" android:layout_height="wrap_content" android:gravity="center_horizontal" android:orientation="vertical" android:padding="5dip" > <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="開始日期" /> <DatePicker android:id="@+id/datePickerStart" android:layout_width="wrap_content" android:layout_height="wrap_content" android:calendarViewShown="false" /> </LinearLayout> <ImageView android:layout_width="wrap_content" android:layout_height="fill_parent" android:src="@drawable/fenge" /> <LinearLayout android:layout_width="wrap_content" android:layout_height="wrap_content" android:gravity="center_horizontal" android:orientation="vertical" android:padding="5dip" > <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="結束日期" /> <DatePicker android:id="@+id/datePickerEnd" android:layout_width="wrap_content" android:layout_height="wrap_content" android:calendarViewShown="false" /> </LinearLayout> </LinearLayout>
然後,在src的 默認包下新建文件DoubleDatePickerDialog.java,內容如下:
/* * Copyright (C) 2007 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.example.doubledatepicker; import java.lang.reflect.Field; import android.app.AlertDialog; import android.content.Context; import android.content.DialogInterface; import android.content.DialogInterface.OnClickListener; import android.os.Bundle; import android.view.LayoutInflater; import android.view.View; import android.widget.DatePicker; import android.widget.DatePicker.OnDateChangedListener; /** * A simple dialog containing an {@link android.widget.DatePicker}. * * <p> * See the <a href="{@docRoot}guide/topics/ui/controls/pickers.html">Pickers</a> * guide. * </p> */ public class DoubleDatePickerDialog extends AlertDialog implements OnClickListener, OnDateChangedListener { private static final String START_YEAR = "start_year"; private static final String END_YEAR = "end_year"; private static final String START_MONTH = "start_month"; private static final String END_MONTH = "end_month"; private static final String START_DAY = "start_day"; private static final String END_DAY = "end_day"; private final DatePicker mDatePicker_start; private final DatePicker mDatePicker_end; private final OnDateSetListener mCallBack; /** * The callback used to indicate the user is done filling in the date. */ public interface OnDateSetListener { /** * @param view * The view associated with this listener. * @param year * The year that was set. * @param monthOfYear * The month that was set (0-11) for compatibility with * {@link java.util.Calendar}. * @param dayOfMonth * The day of the month that was set. */ void onDateSet(DatePicker startDatePicker, int startYear, int startMonthOfYear, int startDayOfMonth, DatePicker endDatePicker, int endYear, int endMonthOfYear, int endDayOfMonth); } /** * @param context * The context the dialog is to run in. * @param callBack * How the parent is notified that the date is set. * @param year * The initial year of the dialog. * @param monthOfYear * The initial month of the dialog. * @param dayOfMonth * The initial day of the dialog. */ public DoubleDatePickerDialog(Context context, OnDateSetListener callBack, int year, int monthOfYear, int dayOfMonth) { this(context, 0, callBack, year, monthOfYear, dayOfMonth); } public DoubleDatePickerDialog(Context context, int theme, OnDateSetListener callBack, int year, int monthOfYear, int dayOfMonth) { this(context, 0, callBack, year, monthOfYear, dayOfMonth, true); } /** * @param context * The context the dialog is to run in. * @param theme * the theme to apply to this dialog * @param callBack * How the parent is notified that the date is set. * @param year * The initial year of the dialog. * @param monthOfYear * The initial month of the dialog. * @param dayOfMonth * The initial day of the dialog. */ public DoubleDatePickerDialog(Context context, int theme, OnDateSetListener callBack, int year, int monthOfYear, int dayOfMonth, boolean isDayVisible) { super(context, theme); mCallBack = callBack; Context themeContext = getContext(); setButton(BUTTON_POSITIVE, "確 定", this); setButton(BUTTON_NEGATIVE, "取 消", this); // setButton(BUTTON_POSITIVE, // themeContext.getText(android.R.string.date_time_done), this); setIcon(0); LayoutInflater inflater = (LayoutInflater) themeContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE); View view = inflater.inflate(R.layout.date_picker_dialog, null); setView(view); mDatePicker_start = (DatePicker) view.findViewById(R.id.datePickerStart); mDatePicker_end = (DatePicker) view.findViewById(R.id.datePickerEnd); mDatePicker_start.init(year, monthOfYear, dayOfMonth, this); mDatePicker_end.init(year, monthOfYear, dayOfMonth, this); // updateTitle(year, monthOfYear, dayOfMonth); // 如果要隱藏當前日期,則使用下面方法。 if (!isDayVisible) { hidDay(mDatePicker_start); hidDay(mDatePicker_end); } } /** * 隱藏DatePicker中的日期顯示 * * @param mDatePicker */ private void hidDay(DatePicker mDatePicker) { Field[] datePickerfFields = mDatePicker.getClass().getDeclaredFields(); for (Field datePickerField : datePickerfFields) { if ("mDaySpinner".equals(datePickerField.getName())) { datePickerField.setAccessible(true); Object dayPicker = new Object(); try { dayPicker = datePickerField.get(mDatePicker); } catch (IllegalAccessException e) { e.printStackTrace(); } catch (IllegalArgumentException e) { e.printStackTrace(); } // datePicker.getCalendarView().setVisibility(View.GONE); ((View) dayPicker).setVisibility(View.GONE); } } } public void onClick(DialogInterface dialog, int which) { // Log.d(this.getClass().getSimpleName(), String.format("which:%d", // which)); // 如果是“取 消”按鈕,則返回,如果是“確 定”按鈕,則往下執行 if (which == BUTTON_POSITIVE) tryNotifyDateSet(); } @Override public void onDateChanged(DatePicker view, int year, int month, int day) { if (view.getId() == R.id.datePickerStart) mDatePicker_start.init(year, month, day, this); if (view.getId() == R.id.datePickerEnd) mDatePicker_end.init(year, month, day, this); // updateTitle(year, month, day); } /** * 獲得開始日期的DatePicker * * @return The calendar view. */ public DatePicker getDatePickerStart() { return mDatePicker_start; } /** * 獲得結束日期的DatePicker * * @return The calendar view. */ public DatePicker getDatePickerEnd() { return mDatePicker_end; } /** * Sets the start date. * * @param year * The date year. * @param monthOfYear * The date month. * @param dayOfMonth * The date day of month. */ public void updateStartDate(int year, int monthOfYear, int dayOfMonth) { mDatePicker_start.updateDate(year, monthOfYear, dayOfMonth); } /** * Sets the end date. * * @param year * The date year. * @param monthOfYear * The date month. * @param dayOfMonth * The date day of month. */ public void updateEndDate(int year, int monthOfYear, int dayOfMonth) { mDatePicker_end.updateDate(year, monthOfYear, dayOfMonth); } private void tryNotifyDateSet() { if (mCallBack != null) { mDatePicker_start.clearFocus(); mDatePicker_end.clearFocus(); mCallBack.onDateSet(mDatePicker_start, mDatePicker_start.getYear(), mDatePicker_start.getMonth(), mDatePicker_start.getDayOfMonth(), mDatePicker_end, mDatePicker_end.getYear(), mDatePicker_end.getMonth(), mDatePicker_end.getDayOfMonth()); } } @Override protected void onStop() { // tryNotifyDateSet(); super.onStop(); } @Override public Bundle onSaveInstanceState() { Bundle state = super.onSaveInstanceState(); state.putInt(START_YEAR, mDatePicker_start.getYear()); state.putInt(START_MONTH, mDatePicker_start.getMonth()); state.putInt(START_DAY, mDatePicker_start.getDayOfMonth()); state.putInt(END_YEAR, mDatePicker_end.getYear()); state.putInt(END_MONTH, mDatePicker_end.getMonth()); state.putInt(END_DAY, mDatePicker_end.getDayOfMonth()); return state; } @Override public void onRestoreInstanceState(Bundle savedInstanceState) { super.onRestoreInstanceState(savedInstanceState); int start_year = savedInstanceState.getInt(START_YEAR); int start_month = savedInstanceState.getInt(START_MONTH); int start_day = savedInstanceState.getInt(START_DAY); mDatePicker_start.init(start_year, start_month, start_day, this); int end_year = savedInstanceState.getInt(END_YEAR); int end_month = savedInstanceState.getInt(END_MONTH); int end_day = savedInstanceState.getInt(END_DAY); mDatePicker_end.init(end_year, end_month, end_day, this); } }
這些代碼是以DatePickerDialog.java為基礎修改的。總的來說,閱讀源碼是一種好習慣。這裡面最需要注意的是hidDay方法,該方法如果調用,則隱藏“日”的選擇框,只能選擇“年月”。這個方法的實現也比較有難度,需要通過反射,找出DatePicker中表示日的字段,並將其設置為隱藏。
還有一點需要注意的是,為了讓控件顯示更加好看,我用了一張名字為fenge.png的圖片,圖片在我提供的源碼中可以找到。
下面就需要編輯activity_main.xml了,這個內容相當簡單,只要一個顯示的text和一個button即可,代碼如下:
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/LinearLayout01" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" > <EditText android:id="@+id/et" android:layout_width="fill_parent" android:layout_height="wrap_content" android:cursorVisible="false" android:editable="false" /> <Button android:id="@+id/dateBtn" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="日期對話框" /> </LinearLayout>
最後,在MainActivity.java中,加入測試代碼:
package com.example.doubledatepicker; import java.util.Calendar; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.DatePicker; import android.widget.TextView; public class MainActivity extends Activity { Button btn; TextView et; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); btn = (Button) findViewById(R.id.dateBtn); et = (TextView) findViewById(R.id.et); btn.setOnClickListener(new View.OnClickListener() { Calendar c = Calendar.getInstance(); @Override public void onClick(View v) { // 最後一個false表示不顯示日期,如果要顯示日期,最後參數可以是true或者不用輸入 new DoubleDatePickerDialog(MainActivity.this, 0, new DoubleDatePickerDialog.OnDateSetListener() { @Override public void onDateSet(DatePicker startDatePicker, int startYear, int startMonthOfYear, int startDayOfMonth, DatePicker endDatePicker, int endYear, int endMonthOfYear, int endDayOfMonth) { String textString = String.format("開始時間:%d-%d-%d\n結束時間:%d-%d-%d\n", startYear, startMonthOfYear + 1, startDayOfMonth, endYear, endMonthOfYear + 1, endDayOfMonth); et.setText(textString); } }, c.get(Calendar.YEAR), c.get(Calendar.MONTH), c.get(Calendar.DATE), true).show(); } }); } }
可以看到,在新建DoubleDatePickerDialog時, 我們實現了一個new DoubleDatePickerDialog.OnDateSetListener()的匿名類,這個類被DoubleDatePickerDialog引用,當DoubleDatePickerDialog中的“確 定”按鈕被點擊時,就會調用匿名類的onDateSet方法。(這也是事件綁定的基本原理)。
DoubleDatePickerDialog構造函數的最後一個參數,true為顯示日期,false為不顯示日期。
當最後一個參數為true時,顯示效果如下:
當最後一個參數為false時,顯示如下
源碼下載地址:http://xiazai.jb51.net/201701/yuanma/DoubleDatePicker_jb51.rar
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