Android中DatePicker只顯示年月的方法

最近項目中有一個選擇信用卡有效期的功能，只需要選擇年月，但是Android原生的DatePicker默認是可以選擇年月日的，所以我們要做下特殊的處理，

並且Android5.0以上和以下的版本的處理方式是不同的

關於5.0以上和以下版本爲什麼這麼處理的原因，詳見so：http://stackoverflow.com/questions/26460682/custom-date-picker-dialog-in-android-lollipop

貼上代碼：

dialog_date_picker.xml

<?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"
    android:orientation="horizontal">
    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:orientation="vertical">
        <DatePicker
            android:id="@+id/datePickerStart"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:calendarViewShown="false"
            android:datePickerMode="spinner"/>
    </LinearLayout>
</LinearLayout>

DatePickerDialog.java

import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.content.res.Resources;
import android.os.Build;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.DatePicker;
import android.widget.DatePicker.OnDateChangedListener;

import java.lang.reflect.Field;


public class DatePickerDialog extends AlertDialog implements OnClickListener, OnDateChangedListener {

    private static final String START_YEAR = "start_year";
    private static final String START_MONTH = "start_month";
    private static final String START_DAY = "start_day";

    private final DatePicker mDatePickerStart;
    private final OnDateSetListener mCallBack;

    public interface OnDateSetListener {
        void onDateSet(DatePicker startDatePicker, int startYear, int startMonthOfYear, int startDayOfMonth);
    }

    public DatePickerDialog(Context context, OnDateSetListener callBack, int year, int monthOfYear, int dayOfMonth) {
        this(context, 0, callBack, year, monthOfYear, dayOfMonth);
    }


    public DatePickerDialog(Context context, int theme, OnDateSetListener callBack, int year, int monthOfYear,
                            int dayOfMonth) {
        super(context, theme);

        mCallBack = callBack;

        Context themeContext = getContext();
        setButton(BUTTON_POSITIVE, "確 定", this);
        setButton(BUTTON_NEGATIVE, "取 消", this);
        setIcon(0);

        LayoutInflater inflater = (LayoutInflater) themeContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View view = inflater.inflate(R.layout.dialog_date_picker, null);
        setView(view);
        mDatePickerStart = (DatePicker) view.findViewById(R.id.datePickerStart);
        mDatePickerStart.init(year, monthOfYear, dayOfMonth, this);

        hideDay(mDatePickerStart);
    }

    private void hideDay(DatePicker mDatePicker) {
        try {
            /* 處理android5.0以上的特殊情況 */
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                int daySpinnerId = Resources.getSystem().getIdentifier("day", "id", "android");
                if (daySpinnerId != 0) {
                    View daySpinner = mDatePicker.findViewById(daySpinnerId);
                    if (daySpinner != null) {
                        daySpinner.setVisibility(View.GONE);
                    }
                }
            } else {
                Field[] datePickerfFields = mDatePicker.getClass().getDeclaredFields();
                for (Field datePickerField : datePickerfFields) {
                    if ("mDaySpinner".equals(datePickerField.getName()) || ("mDayPicker").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();
                        }
                        ((View) dayPicker).setVisibility(View.GONE);
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void onClick(DialogInterface dialog, int which) {
        if (which == BUTTON_POSITIVE)
            tryNotifyDateSet();
    }

    @Override
    public void onDateChanged(DatePicker view, int year, int month, int day) {
        if (view.getId() == R.id.datePickerStart)
            mDatePickerStart.init(year, month, day, this);
    }

    public DatePicker getDatePickerStart() {
        return mDatePickerStart;
    }


    public void updateStartDate(int year, int monthOfYear, int dayOfMonth) {
        mDatePickerStart.updateDate(year, monthOfYear, dayOfMonth);
    }


    private void tryNotifyDateSet() {
        if (mCallBack != null) {
            mDatePickerStart.clearFocus();
            mCallBack.onDateSet(mDatePickerStart, mDatePickerStart.getYear(), mDatePickerStart.getMonth(),
                    mDatePickerStart.getDayOfMonth());
        }
    }

    @Override
    protected void onStop() {
        super.onStop();
    }

    @Override
    public Bundle onSaveInstanceState() {
        Bundle state = super.onSaveInstanceState();
        state.putInt(START_YEAR, mDatePickerStart.getYear());
        state.putInt(START_MONTH, mDatePickerStart.getMonth());
        state.putInt(START_DAY, mDatePickerStart.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);
        mDatePickerStart.init(start_year, start_month, start_day, this);

    }
}

MainActivity.java

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.TextView;

import java.util.Calendar;

public class MainActivity extends Activity {
    private Button mShowDateBTN;
    private TextView mSelectDateTV;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mShowDateBTN = (Button) findViewById(R.id.btn_show_date);
        mSelectDateTV = (TextView) findViewById(R.id.tv_select_date);

        mShowDateBTN.setOnClickListener(new View.OnClickListener() {
            Calendar c = Calendar.getInstance();

            @Override
            public void onClick(View v) {
                new DatePickerDialog(MainActivity.this, 0, new DatePickerDialog.OnDateSetListener() {
                    @Override
                    public void onDateSet(DatePicker startDatePicker, int startYear, int startMonthOfYear,
                                          int startDayOfMonth) {
                        String textString = String.format("選擇年月：%d-%d\n", startYear,
                                startMonthOfYear + 1);
                        mSelectDateTV.setText(textString);
                    }
                }, c.get(Calendar.YEAR), c.get(Calendar.MONTH), c.get(Calendar.DATE)).show();
            }
        });
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
    <Button
        android:id="@+id/btn_show_date"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="open date"/>
    <TextView
        android:id="@+id/tv_select_date"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
</LinearLayout>