如何通过Android应用程序设置设备时间

Question

我创建了一个android应用程序，它必须设置设备的时间，因为设备不能记住时间。不知道如何设置设备的时间。

Date c = Calendar.getInstance().getTime();
SimpleDateFormat df = new SimpleDateFormat("dd-MMM-yyyy 
HH:mm:ss");
String formattedDate = df.format(c);

SharedPreferences time = getSharedPreferences("PREFS",0);

Date Time = null;
try {
    Time = df.parse(time.getString("time",""));
} catch (ParseException e) {
    e.printStackTrace();
}
if (Time == null)
{
    SharedPreferences.Editor editor = time.edit();
    editor.putString("time", formattedDate);
    editor.apply();
    Toast.makeText(MainActivity.this, formattedDate, 
    Toast.LENGTH_SHORT).show();
}
else
{
    try {
        if (Time.before(df.parse(formattedDate)))
        {
            SharedPreferences.Editor editor = time.edit();
            editor.putString("time", formattedDate);
            editor.apply();

            **** I want set device's time here from "time"
        }
        if (Time.after(df.parse(formattedDate)))
        {
            **** I want set device's time here from "time"
        }
    } catch (ParseException e) {
        e.printStackTrace();
    }
}

Answer 1

在清单文件中添加以下行以请求权限：

<uses-permission android:name="android.permission.SET_TIME"
        tools:ignore="ProtectedPermissions" />
    <permission android:name="android.permission.SET_TIME" android:protectionLevel="signature|system"/>

在java代码中：

Calendar c = Calendar.getInstance();
    c.set(year, month, day, hour, minutes, seconds);
    AlarmManager am = (AlarmManager) this.getSystemService(Context.ALARM_SERVICE);
    am.setTime(c.getTimeInMillis());