所以我有一个小问题。我有一种简单的感觉，我必须要忽视它。在我的第二个片段中，我正在写共享偏好一定数量的键和应用（）后记。在我将数据写入共享偏好后，我用主片段（片段＃1）替换当前片段（片段＃2）。加载此片段后，我调用readPreferences（），它应该读取存储的数据，并将数据写入我在主片段上的各种文本视图。这不会发生。我不确定此时是否由于写入错误或读取错误。你的帮助一如既往，赞赏。感谢。
第二片段
package lucaclock.moticlock;
import android.app.AlertDialog;
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.content.Context;
import android.content.DialogInterface;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.SeekBar;
import android.widget.TextView;
import android.widget.TimePicker;
import android.widget.Toast;
public class secondFragment extends Fragment {
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
private TimePicker timePicker;
private int hour = 0;
private int min = 0;
private String mParam1;
private String mParam2;
public SharedPreferences sharedPreferences;
public SharedPreferences.Editor prefEditor;
public static final String alarmPreferences = "alarmPreferences";
public static final String alarmTimeKey = "alarmTimeKey";
public static final String alarmNameKey = "alarmNameKey";
public static final String alarmOccuranceKey = "alarmOccuranceKey";
public static final String alarmVolumeKey = "alarmVolumeKey";
public static final String alarmSnoozeKey = "alarmSnoozeKey";
public static final String alarmVisibleKey = "alarmVisibleKey";
public int snoozeTime;
public secondFragment() {
// Required empty public constructor
}
// TODO: Rename and change types and number of parameters
public static secondFragment newInstance(String param1, String param2) {
secondFragment fragment = new secondFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
public View onCreateView(final LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final View view = inflater.inflate(R.layout.fragment_second, container, false);
sharedPreferences = getActivity().getPreferences(Context.MODE_PRIVATE);
final Button btnOK = (Button) view.findViewById(R.id.btnOK);
final TimePicker tp = (TimePicker) view.findViewById(R.id.timePicker);
//Stage 1 Components
final EditText edAlarmName = (EditText) view.findViewById(R.id.edAlarmName);
edAlarmName.setOnTouchListener(new View.OnTouchListener()
{
public boolean onTouch(View view, MotionEvent event)
{
if(event.getAction() == MotionEvent.ACTION_DOWN)
{
edAlarmName.setText("");
}
return false;
}
});
final EditText edAlarmTime = (EditText) view.findViewById(R.id.edTime);
final EditText edOccurance = (EditText) view.findViewById(R.id.edOccurance);
edOccurance.setOnTouchListener(new View.OnTouchListener()
{
public boolean onTouch(View v, MotionEvent event)
{
if(event.getAction() == MotionEvent.ACTION_DOWN)
{
dialogOccurance(view);
return true;
}
return false;
}
});
final SeekBar seekVolume = (SeekBar) view.findViewById(R.id.seekVolume);
seekVolume.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener()
{
TextView tv = (TextView) view.findViewById(R.id.txtVolume);
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
// TODO Auto-generated method stub
tv.setText("How Loud?");
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
// TODO Auto-generated method stub
}
@Override
public void onProgressChanged(SeekBar seekBar, int progress,boolean fromUser) {
// TODO Auto-generated method stub
tv.setText("Volume: " + Integer.toString(progress));
//Toast.makeText(getApplicationContext(), String.valueOf(progress), Toast.LENGTH_LONG).show();
}
});
final RadioButton rad5min = (RadioButton) view.findViewById(R.id.radSnooze5min);
final RadioButton rad10min = (RadioButton) view.findViewById(R.id.radSnooze10min);
rad5min.setOnClickListener(new View.OnClickListener()
{
public void onClick(View view)
{
if(rad5min.isChecked() == true)
{
rad10min.setChecked(false);
snoozeTime = 5;
}
}
});
rad10min.setOnClickListener(new View.OnClickListener()
{
public void onClick(View view)
{
if(rad10min.isChecked() == true)
{
rad5min.setChecked(false);
snoozeTime = 10;
}
}
});
final EditText edCustomSnooze = (EditText) view.findViewById(R.id.edSnoozeTime);
edCustomSnooze.setOnTouchListener(new View.OnTouchListener()
{
public boolean onTouch(View view, MotionEvent motion)
{
edCustomSnooze.setText("");
if(motion.getAction() == MotionEvent.ACTION_DOWN)
{
rad5min.setChecked(false);
rad10min.setChecked(false);
snoozeTime = 0;
}
return false;
}
});
Button btnSave = (Button) view.findViewById(R.id.btnSaveAlarm);
TextView txtOccur = (TextView) view.findViewById(R.id.txtOccur);
final TextView txtVolume = (TextView) view.findViewById(R.id.txtVolume);
TextView txtSnooze = (TextView) view.findViewById(R.id.txtSnooze);
final Button btnCancel = (Button) view.findViewById(R.id.btnCancel);
btnOK.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
String minString = null;
tp.setIs24HourView(false);
hour = tp.getCurrentHour();
min = tp.getCurrentMinute();
if(min < 10)
{
minString = new StringBuilder().append(Integer.toString(0)).append(min).toString();
}
else
minString = new StringBuilder().append(Integer.toString(min)).toString();
//tv.setText(formatTime(hour, minString));
//storeSetAlarmTime(formatTime(hour, minString));
setVisibleStage(0, view);
setVisibleStage(1, view);
edAlarmTime.setText(formatTime(hour, minString));
//HomeFragment hFrag = new HomeFragment();
//replaceFragment(hFrag);
}
});
btnCancel.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
HomeFragment hFrag = new HomeFragment();
replaceFragment(hFrag);
}
});
btnSave.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View view)
{
edAlarmName.clearFocus();
edAlarmTime.clearFocus();
edOccurance.clearFocus();
edCustomSnooze.clearFocus();
//INPUT VALIDATION
//ALL INPUT IS OK. NO NULL VALUES ANYWHERE. PROCEED...
if(validateInput(edAlarmTime, edAlarmName, edOccurance, seekVolume, rad5min, rad10min, edCustomSnooze))
{
saveData(view, edAlarmName.getText().toString(), edAlarmTime.getText().toString(), edOccurance.getText().toString(), seekVolume.getProgress(), snoozeTime, sharedPreferences);
//dialogBuilder("Alarm Saved", "Your alarm has been saved");
}
else
dialogBuilder("Validation Error", "Fix your input and try again");
}
});
edAlarmTime.setOnTouchListener(new View.OnTouchListener()
{
public boolean onTouch(View view, MotionEvent event)
{
if(event.getAction() == MotionEvent.ACTION_DOWN)
{
}
return false;
}
});
return view;
}
public void dialogBuilder(String title, String message)
{
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
builder.setTitle(title);
builder.setMessage(message);
builder.show();
}
public void dialogOccurance(final View view)
{
CharSequence colors[] = new CharSequence[] {"Once", "Daily", "Weekly"};
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
builder.setTitle("How often will this alarm repeat?");
builder.setItems(colors, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
TextView tv = (TextView) view.findViewById(R.id.edOccurance);
if(which == 0)
{
tv.setText("ONCE");
}
else if(which == 1)
tv.setText("DAILY");
else if(which == 2)
tv.setText("WEEKLY");
}
});
builder.show();
}
public void saveData(View view, String alarmName, String alarmTime, String occurance, int volume, int snoozeTime, SharedPreferences sharedPreferences)
{
prefEditor = sharedPreferences.edit();
prefEditor.putString(alarmTimeKey, alarmTime);
prefEditor.putString(alarmNameKey, alarmName);
prefEditor.putString(alarmOccuranceKey, occurance);
prefEditor.putInt(alarmVolumeKey, volume);
prefEditor.putInt(alarmSnoozeKey, snoozeTime);
prefEditor.putBoolean(alarmVisibleKey, true);
prefEditor.commit();
if(!sharedPreferences.getBoolean(alarmVisibleKey, true))
{
dialogBuilder("ERROR", "We tried writing the data, however we cant verify it exists");
}
else
{
dialogBuilder("Write Successfull", "true");
}
Toast.makeText(getActivity().getApplicationContext(), "Alarm Added", Toast.LENGTH_LONG).show();
HomeFragment hFrag = new HomeFragment();
replaceFragment(hFrag);
}
public void setVisibleStage(int stage, View view)
{
//Stage 0 Components
TimePicker tp = (TimePicker) view.findViewById(R.id.timePicker);
Button btnOK = (Button) view.findViewById(R.id.btnOK);
Button btnCancel = (Button) view.findViewById(R.id.btnCancel);
//Stage 1 Components
EditText edAlarmName = (EditText) view.findViewById(R.id.edAlarmName);
EditText edAlarmTime = (EditText) view.findViewById(R.id.edTime);
EditText edOccurance = (EditText) view.findViewById(R.id.edOccurance);
SeekBar seekVolume = (SeekBar) view.findViewById(R.id.seekVolume);
RadioButton rad5min = (RadioButton) view.findViewById(R.id.radSnooze5min);
RadioButton rad10min = (RadioButton) view.findViewById(R.id.radSnooze10min);
EditText edCustomSnooze = (EditText) view.findViewById(R.id.edSnoozeTime);
Button btnSave = (Button) view.findViewById(R.id.btnSaveAlarm);
TextView txtOccur = (TextView) view.findViewById(R.id.txtOccur);
TextView txtVolume = (TextView) view.findViewById(R.id.txtVolume);
TextView txtSnooze = (TextView) view.findViewById(R.id.txtSnooze);
if(stage == 0)
{
//STAGE 0 = ANALOG CLOCK DISPLAY ONLY
tp.setVisibility(view.INVISIBLE);
btnOK.setVisibility(view.INVISIBLE);
btnCancel.setVisibility(view.INVISIBLE);
}
else if(stage == 1)
{
//STAGE 1 = EVERYTHING ELSE VISIBLE
edAlarmName.setVisibility(view.VISIBLE);
edAlarmTime.setVisibility(view.VISIBLE);
txtOccur.setVisibility(view.VISIBLE);
edOccurance.setVisibility(view.VISIBLE);
txtVolume.setVisibility(view.VISIBLE);
seekVolume.setVisibility(view.VISIBLE);
txtSnooze.setVisibility(view.VISIBLE);
rad5min.setVisibility(view.VISIBLE);
rad10min.setVisibility(view.VISIBLE);
edCustomSnooze.setVisibility(view.VISIBLE);
btnSave.setVisibility(view.VISIBLE);
}
}
public void replaceFragment(Fragment fragment)
{
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.frame_container, fragment);
//fragmentTransaction.addToBackStack(fragment.toString());
fragmentTransaction.commit();
}
public boolean validateInput(EditText edAlarmTime, EditText edAlarmName, EditText edOccurance, SeekBar seekVolume, RadioButton rad5min, RadioButton rad10min, EditText customSnooze)
{
String alarmTimeOK = edAlarmTime.getText().toString();
String alarmNameOK = edAlarmName.getText().toString();
String OccuranceOK = edOccurance.getText().toString();
int volumeOK = seekVolume.getProgress();
boolean FiveMinChecked = rad5min.isChecked();
boolean TenMinChecked = rad10min.isChecked();
String customSnoozeOK = customSnooze.getText().toString();
if(alarmTimeOK.matches("") || !alarmTimeOK.contains(":"))
return false;
else if(alarmNameOK.matches("") || alarmNameOK.contains("Alarm Name"))
return false;
else if(OccuranceOK.matches("") || OccuranceOK.contains("Choose Occurance"))
return false;
else if(volumeOK == 0)
return false;
else if(FiveMinChecked && customSnoozeOK.matches("Enter your own"))
return true;
else if(TenMinChecked && customSnoozeOK.matches("Enter your own"))
return true;
else if(FiveMinChecked == false && customSnoozeOK.matches("Enter your own"))
return false;
else if(TenMinChecked == false && customSnoozeOK.matches("Enter your own"))
return false;
else
return true;
}
public String formatTime(int hour, String minString)
{
String formattedString = null;
if(hour > 12)
{
formattedString = new StringBuilder().append(Integer.toString(hour - 12)).append(":").append(minString).append("PM").toString();
}
else
formattedString = new StringBuilder().append(Integer.toString(hour)).append(":").append(minString).append("AM").toString();
return formattedString;
}
}
Home Fragment
public class HomeFragment extends Fragment{
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
private boolean alarm1Active = false;
//private boolean alarm1Visible = false;
//public String alarm1Name;
//public String alarm1Time;
//public String alarm1Occurance;
//public int alarm1Snooze;
//public int alarm1Volume;
//public boolean fragmentSwitch;
SharedPreferences sharedPreferences;
SharedPreferences.Editor prefEditor;
public static final String alarmPreferences = "alarmPreferences";
public static final String alarmTimeKey = "alarmTimeKey";
public static final String alarmNameKey = "alarmNameKey";
public static final String alarmOccuranceKey = "alarmOccuranceKey";
public static final String alarmVolumeKey = "alarmVolumeKey";
public static final String alarmSnoozeKey = "alarmSnoozeKey";
public static final String alarmVisibleKey = "alarmVisibleKey";
public boolean devMode = true;
public HomeFragment() {
// Required empty public constructor
}
public static HomeFragment newInstance(String param1, String param2) {
HomeFragment fragment = new HomeFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
final View view = inflater.inflate(R.layout.fragment_home, container, false);
//CODE HERE
readPreferences(view);
FloatingActionButton fabAddAlarm = (FloatingActionButton) view.findViewById(R.id.fabRefresh);
fabAddAlarm.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
Toast.makeText(getActivity().getApplicationContext(), "Reading Preferences", Toast.LENGTH_LONG).show();
readPreferences(view);
}
});
return view;
}
public void readPreferences(View view)
{
TextView tvAlarm1Name = (TextView) view.findViewById(R.id.tvAlarm1Name);
TextView tvAlarm1Time = (TextView) view.findViewById(R.id.tvAlarm1Time);
TextView tvAlarm1Occurance = (TextView) view.findViewById(R.id.tvAlarm1Occurance);
Switch swAlarm1Active = (Switch) view.findViewById(R.id.swEnableAlarm1);
Button btnEditAlarm1 = (Button) view.findViewById(R.id.btnEditAlarm1);
TextView status = (TextView) view.findViewById(R.id.tvNoAlarms);
sharedPreferences = getActivity().getSharedPreferences(alarmPreferences, Context.MODE_PRIVATE);
String alarm1Name = sharedPreferences.getString(alarmNameKey, null);
String alarm1Time = sharedPreferences.getString(alarmTimeKey, null);
String alarm1Occurance = sharedPreferences.getString(alarmOccuranceKey, null);
int alarm1Snooze = sharedPreferences.getInt(alarmSnoozeKey, 0);
int alarm1Volume = sharedPreferences.getInt(alarmVolumeKey, 0);
boolean alarm1Visible = sharedPreferences.getBoolean(alarmVisibleKey, false);
if(!alarm1Visible)
{
status.setVisibility(View.VISIBLE);
status.setText("You have no alarms set!");
}
else if(alarm1Visible)
{
status.setVisibility(View.INVISIBLE);
tvAlarm1Time.setVisibility(View.VISIBLE);
tvAlarm1Name.setVisibility(View.VISIBLE);
tvAlarm1Occurance.setVisibility(View.VISIBLE);
btnEditAlarm1.setVisibility(View.VISIBLE);
swAlarm1Active.setVisibility(View.VISIBLE);
tvAlarm1Time.setText(alarm1Time);
tvAlarm1Name.setText(alarm1Name);
tvAlarm1Occurance.setText(alarm1Occurance);
}
}
}
答案 0 :(得分：0)
在null上保存字符串时，请确保您没有保存prefEditor.putString(alarmOccuranceKey, occurance);
。它将改为清除首选项键。
occurance确保Metric不为空。
答案 1 :(得分：0)
请使用commit（）保存数据。您还可以为SharedPreferences创建一个简单的可重用类。请参考我的自定义课程：https://codebegetter.wordpress.com/2016/08/04/shared-preferences-reusable-class/
答案 2 :(得分：0)
根据其中一个答案中的评论，您似乎已经应用了解决方案。但是，根据您在此处发布的代码是问题：
您不存储和检索同一SharedPreferences文件中的值。存储值时，您使用的是自定义名为SharedPreferences的文件。当您尝试检索这些值时，您引用了SharedPreferences文件，该文件特定于承载您的secondFragment的Activity。 （在某种程度上，它实际上是自定义命名的......框架基于你的Activity名称）。
当您在secondFragment中将值写入SharedPreferences时，请致电：
sharedPreferences = getActivity().getSharedPreferences(alarmPreferences, Context.MODE_PRIVATE);
//...
prefEditor = sharedPreferences.edit();
当您尝试在HomeFragment中阅读这些值时，请致电：
sharedPreferences = getActivity().getPreferences(Context.MODE_PRIVATE);
这两个代码段不引用相同的SharePreferences文件。最直接的解决方案是更新HomeFragment中的代码，以便获得存储值的相同SharePreferences文件，如下所示：
sharedPreferences = getActivity().getSharedPreferences(alarmPreferences, Context.MODE_PRIVATE);