android 時鐘控件

時鐘控件包括AnalogClock和DigitalClock，它們都負責顯示時鐘，所不同的是AnalogClock控件顯示模擬時鐘，且只顯示時針和分針，而DigitalClock顯示數字時鐘，可精確到秒

控件代碼如下：

 

<?xml version="1.0" encoding="utf-8"?>
<!-- AnalogClock與DigitalClock這兩個時鐘控件都不需要Java代碼，
只要在layout的xml裏插入以下代碼即可自動顯示時間-->
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <!-- 模擬時鐘控件 -->
    <AnalogClock android:id="@+id/analogClock"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"/>
    <!-- 數字時鐘控件 -->
    <DigitalClock android:id="@+id/digitalClock"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"/>
</LinearLayout>

DigitalClock自定義日期輸出格式

通過看源碼可知，只需修改以下兩行代碼其他全部複製過來即可：

  

private final static String m12 = "h:mm:ss aa";
    private final static String m24 = "k:mm:ss";

如果想做得更好更通用的話可以把設置日期格式的方法暴露出來，或者爲其增加一個xml屬性。

完整代碼:

Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/-->package com.test;

import java.util.Calendar;

import android.content.Context;
import android.content.res.Resources;
import android.database.ContentObserver;
import android.os.Handler;
import android.os.SystemClock;
import android.provider.Settings;
import android.text.format.DateFormat;
import android.util.AttributeSet;

/**
 * 自定義DigitalClock輸出格式
 * @author 農民伯伯
 *
 */
public class DigitalClock extends android.widget.DigitalClock {

    Calendar mCalendar;
    private final static String m12 = "h:mm aa";//h:mm:ss aa
    private final static String m24 = "k:mm";//k:mm:ss
    private FormatChangeObserver mFormatChangeObserver;

    private Runnable mTicker;
    private Handler mHandler;

    private boolean mTickerStopped = false;

    String mFormat;

    public DigitalClock(Context context) {
        super(context);
        initClock(context);
    }

    public DigitalClock(Context context, AttributeSet attrs) {
        super(context, attrs);
        initClock(context);
    }

    private void initClock(Context context) {
        Resources r = context.getResources();

        if (mCalendar == null) {
            mCalendar = Calendar.getInstance();
        }

        mFormatChangeObserver = new FormatChangeObserver();
        getContext().getContentResolver().registerContentObserver(
                Settings.System.CONTENT_URI, true, mFormatChangeObserver);

        setFormat();
    }

    @Override
    protected void onAttachedToWindow() {
        mTickerStopped = false;
        super.onAttachedToWindow();
        mHandler = new Handler();

        /**
         * requests a tick on the next hard-second boundary
         */
        mTicker = new Runnable() {
                public void run() {
                    if (mTickerStopped) return;
                    mCalendar.setTimeInMillis(System.currentTimeMillis());
                    setText(DateFormat.format(mFormat, mCalendar));
                    invalidate();
                    long now = SystemClock.uptimeMillis();
                    long next = now + (1000 - now % 1000);
                    mHandler.postAtTime(mTicker, next);
                }
            };
        mTicker.run();
    }

    @Override
    protected void onDetachedFromWindow() {
        super.onDetachedFromWindow();
        mTickerStopped = true;
    }

    /**
     * Pulls 12/24 mode from system settings
     */
    private boolean get24HourMode() {
        return android.text.format.DateFormat.is24HourFormat(getContext());
    }

    private void setFormat() {
        if (get24HourMode()) {
            mFormat = m24;
        } else {
            mFormat = m12;
        }
    }

    private class FormatChangeObserver extends ContentObserver {
        public FormatChangeObserver() {
            super(new Handler());
        }

        @Override
        public void onChange(boolean selfChange) {
            setFormat();
        }
    }
}

使用方法  

<com.test.DigitalClock android:layout_x="15dp" android:layout_y="30dp" 
            android:layout_width="wrap_content" android:layout_height="wrap_content"
            android:textColor="@android:color/white" android:textSize="55sp"
             android:shadowColor="@android:color/white" android:shadowRadius="2.0"
            >
        </com.test.DigitalClock>