这个是在网上能搜到的方法，用来判断当前系统是12小时制或者24小时制，当时做项目用的就是这个判断。
ContentResolver cv = this.getContentResolver();
String strTimeFormat = android.provider.Settings.System.getString(cv,
android.provider.Settings.System.TIME_12_24);
if(strTimeFormat.equals("24")){
Log.i("activity","24");
}以上来自： http://www.cnblogs.com/liwqiang/archive/2010/08/08/1795172.html，感谢他的分享，解决了我当时的问题。
最近没事看了看DeskClock的源码，里边也有一个判断是否是24小时制的方法，API提供的，写的更加完善，考虑的更加周全。
/**
* @return true if clock is set to 24-hour mode
*/
public static boolean get24HourMode(final Context context) {
return android.text.format.DateFormat.is24HourFormat(context);
}进入源码
/**
* Returns true if user preference is set to 24-hour format.
* @param context the context to use for the content resolver
* @return true if 24 hour time format is selected, false otherwise.
*/
public static boolean is24HourFormat(Context context) {
String value = https://www.it610.com/article/Settings.System.getString(context.getContentResolver(),
Settings.System.TIME_12_24);
if (value == null) {
Locale locale = context.getResources().getConfiguration().locale;
synchronized (sLocaleLock) {
if (sIs24HourLocale != null && sIs24HourLocale.equals(locale)) {
return sIs24Hour;
}
}java.text.DateFormat natural =
java.text.DateFormat.getTimeInstance(java.text.DateFormat.LONG, locale);
if (natural instanceof SimpleDateFormat) {
SimpleDateFormat sdf = (SimpleDateFormat) natural;
String pattern = sdf.toPattern();
if (pattern.indexOf('H') >= 0) {
value = "https://www.it610.com/article/24";
} else {
value = "https://www.it610.com/article/12";
}
} else {
value = "https://www.it610.com/article/12";
}synchronized (sLocaleLock) {
sIs24HourLocale = locale;
sIs24Hour = value.equals("24");
}return sIs24Hour;
}return value.equals("24");
}【获取Android系统时间是24小时制还是12小时制】
