Implementing Android TimePicker from Tutorial – Source Force Closes-Collection of common programming errors
I’m trying to implement a TimePicker into my source code from the following tutorial:
http://www.lukehorvat.com/blog/android-time-picker-example/
However when implementing it in my app – I’m getting force close issues.
Any suggestions?
JAVA:
import android.app.Activity;
import android.app.AlertDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.ViewGroup;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.FrameLayout;
import android.widget.TimePicker;
import android.os.Bundle;
import android.support.v4.app.DialogFragment;
import android.support.v4.app.FragmentActivity;
import android.text.format.DateFormat;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.app.Activity;
import android.app.Dialog;
import android.app.TimePickerDialog;
import android.os.Bundle;
import android.support.v4.app.DialogFragment;
import android.text.format.DateFormat;
import android.widget.TimePicker;
import com.nfc.linkingmanager.TimePickerFragment.TimePickedListener;
import java.util.Calendar;
public class AddEditCountry extends Activity implements TimePickedListener
{
private TextView mPickedTimeText;
private Button mPickTimeButton;
private long rowID;
private EditText nameEt;
private EditText capEt;
private EditText codeEt;
private TimePicker timeEt;
public static final String KEY_BUNDLE_TIME = "time";
public static final String KEY_BUNDLE_MIN = "min";
@Override
public void onCreate(Bundle savedInstanceState)
{
nameEt = (EditText) findViewById(R.id.nameEdit);
capEt = (EditText) findViewById(R.id.capEdit);
codeEt = (EditText) findViewById(R.id.codeEdit);
timeEt = (TimePicker) findViewById(R.id.timeEdit);
Bundle extras = getIntent().getExtras();
if (extras != null)
{
rowID = extras.getLong("row_id");
nameEt.setText(extras.getString("name"));
capEt.setText(extras.getString("cap"));
codeEt.setText(extras.getString("code"));
timeEt.setCurrentHour(extras.containsKey(KEY_BUNDLE_TIME) ? extras.getInt(KEY_BUNDLE_TIME) : 0);
}
Button saveButton =(Button) findViewById(R.id.saveBtn);
saveButton.setOnClickListener(new OnClickListener() {
public void onClick(View v)
{
if (nameEt.getText().length() != 0)
{
AsyncTask saveContactTask =
new AsyncTask()
{
@Override
protected Object doInBackground(Object... params)
{
saveContact();
return null;
}
@Override
protected void onPostExecute(Object result)
{
finish();
}
};
saveContactTask.execute((Object[]) null);
}
else
{
AlertDialog.Builder alert = new AlertDialog.Builder(AddEditCountry.this);
alert.setTitle(R.string.errorTitle);
alert.setMessage(R.string.errorMessage);
alert.setPositiveButton(R.string.errorButton, null);
alert.show();
}
}
});
}
private void saveContact()
{
DatabaseConnector dbConnector = new DatabaseConnector(this);
if (getIntent().getExtras() == null)
{
dbConnector.insertContact(nameEt.getText().toString(),
capEt.getText().toString(),
timeEt.getCurrentHour().toString(),
codeEt.getText().toString());
}
else
{
dbConnector.updateContact(rowID,
nameEt.getText().toString(),
capEt.getText().toString(),
timeEt.getCurrentHour().toString(),
codeEt.getText().toString());
}
}
@Override
public void onTimePicked(Calendar time)
{
// display the selected time in the TextView
mPickedTimeText.setText(DateFormat.format("h:mm a", time));
}
}
ADD COUNTRY XML:
TIMEPICKERFRAGMENT.JAVA
package com.nfc.linkingmanager;
import android.app.Activity;
import android.app.Dialog;
import android.app.TimePickerDialog;
import android.os.Bundle;
import android.support.v4.app.DialogFragment;
import android.text.format.DateFormat;
import android.widget.TimePicker;
import java.util.Calendar;
public class TimePickerFragment extends DialogFragment implements TimePickerDialog.OnTimeSetListener
{
private TimePickedListener mListener;
@Override
public Dialog onCreateDialog(Bundle savedInstanceState)
{
// use the current time as the default values for the picker
final Calendar c = Calendar.getInstance();
int hour = c.get(Calendar.HOUR_OF_DAY);
int minute = c.get(Calendar.MINUTE);
// create a new instance of TimePickerDialog and return it
return new TimePickerDialog(getActivity(), this, hour, minute, DateFormat.is24HourFormat(getActivity()));
}
@Override
public void onAttach(Activity activity)
{
// when the fragment is initially shown (i.e. attached to the activity), cast the activity to the callback interface type
super.onAttach(activity);
try
{
mListener = (TimePickedListener) activity;
}
catch (ClassCastException e)
{
throw new ClassCastException(activity.toString() + " must implement " + TimePickedListener.class.getName());
}
}
@Override
public void onTimeSet(TimePicker view, int hourOfDay, int minute)
{
// when the time is selected, send it to the activity via its callback interface method
Calendar c = Calendar.getInstance();
c.set(Calendar.HOUR_OF_DAY, hourOfDay);
c.set(Calendar.MINUTE, minute);
mListener.onTimePicked(c);
}
public static interface TimePickedListener
{
public void onTimePicked(Calendar time);
}
}
LOGCAT:
03-25 02:50:06.783: I/Adreno200-EGLSUB(27045): : Format RGBA_8888.
03-25 02:50:06.783: D/memalloc(27045): ion: Mapped buffer base:0x5ca43000 size:614400 offset:0 fd:57
03-25 02:50:06.783: E/(27045): Can't open file for reading
03-25 02:50:06.783: E/(27045): Can't open file for reading
03-25 02:50:06.823: D/memalloc(27045): ion: Mapped buffer base:0x5d234000 size:614400 offset:0 fd:61
03-25 02:50:08.695: D/Activity(27045): Activity.onPause(), editTextTapSensorList size: 0
03-25 02:50:08.715: W/dalvikvm(27045): threadid=1: thread exiting with uncaught exception (group=0x4108b9d8)
03-25 02:50:08.715: E/AndroidRuntime(27045): FATAL EXCEPTION: main
03-25 02:50:08.715: E/AndroidRuntime(27045): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.nfc.linkingmanager/com.nfc.linkingmanager.AddEditCountry}: java.lang.NullPointerException
03-25 02:50:08.715: E/AndroidRuntime(27045): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1960)
03-25 02:50:08.715: E/AndroidRuntime(27045): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1985)
03-25 02:50:08.715: E/AndroidRuntime(27045): at android.app.ActivityThread.access$600(ActivityThread.java:127)
03-25 02:50:08.715: E/AndroidRuntime(27045): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1151)
03-25 02:50:08.715: E/AndroidRuntime(27045): at android.os.Handler.dispatchMessage(Handler.java:99)
03-25 02:50:08.715: E/AndroidRuntime(27045): at android.os.Looper.loop(Looper.java:137)
03-25 02:50:08.715: E/AndroidRuntime(27045): at android.app.ActivityThread.main(ActivityThread.java:4477)
03-25 02:50:08.715: E/AndroidRuntime(27045): at java.lang.reflect.Method.invokeNative(Native Method)
03-25 02:50:08.715: E/AndroidRuntime(27045): at java.lang.reflect.Method.invoke(Method.java:511)
03-25 02:50:08.715: E/AndroidRuntime(27045): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:788)
03-25 02:50:08.715: E/AndroidRuntime(27045): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:555)
03-25 02:50:08.715: E/AndroidRuntime(27045): at dalvik.system.NativeStart.main(Native Method)
03-25 02:50:08.715: E/AndroidRuntime(27045): Caused by: java.lang.NullPointerException
03-25 02:50:08.715: E/AndroidRuntime(27045): at com.nfc.linkingmanager.AddEditCountry.onCreate(AddEditCountry.java:73)
03-25 02:50:08.715: E/AndroidRuntime(27045): at android.app.Activity.performCreate(Activity.java:4701)
03-25 02:50:08.715: E/AndroidRuntime(27045): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1051)
03-25 02:50:08.715: E/AndroidRuntime(27045): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1924)
03-25 02:50:08.715: E/AndroidRuntime(27045): ... 11 more
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You don’t have an element called TimeEdit in your xml. So when you try to set its text, it crashes with a null pointer exception.
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where you define Timepicker
timeEt = (TimePicker) findViewById(R.id.timeEdit);in your xml file. Check your xml file and give different id to all.