TimePicker NullPointerException on ICS

问题

Alright so I just switched my TimePickerDialog to a TimePicker widget directly visible in the Activity I'm working on because of customer demand.

The problem is when I press any of the arrows on said TimePicker, I get a NullPointerException.

Just to clarify, no code what so ever is attached to the TimePicker except this line in the onCreate() method of my Activity:

((TimePicker) findViewById(R.id.time_picker)).setIs24HourView(true);

I found this post on the Google Forums regarding this issue, but not much help.

Here's my error log, I sadly don't think it'll be much help though.

This issue only appears when testing in ICS (Android 4.0 +). Has anyone been able to work around this issue ?

回答1:

Just wrote a sample application and no error found in Galaxy SIII (4.0):

import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
import android.widget.TimePicker;
import android.widget.TimePicker.OnTimeChangedListener;

public class TimePickerTestActivity extends Activity implements OnTimeChangedListener{

    private TimePicker tpTime = null;
    private TextView tvTime = null;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        tvTime = (TextView)this.findViewById(R.id.tv_time);

        tpTime = (TimePicker)this.findViewById(R.id.tp_time);
        tpTime.setIs24HourView(Boolean.TRUE);
        tpTime.setOnTimeChangedListener(this);

    }
    public void onTimeChanged(TimePicker tp, final int hrOfDay, final int min) {
        if(tp.equals(tpTime)){
            tvTime.post(new Runnable(){

                public void run() {
                    tvTime.setText(hrOfDay+":"+min);
                }

            });
        }
    }
}

And the layout xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout   xmlns:android="http://schemas.android.com/apk/res/android"
                android:layout_width="fill_parent"
                android:layout_height="fill_parent"
                android:orientation="vertical" >

    <TimePicker android:id="@+id/tp_time"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content" />

    <TextView   android:id="@+id/tv_time"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content" />
</LinearLayout>

FYI: http://developer.android.com/reference/android/widget/TimePicker.html

来源：https://stackoverflow.com/questions/9299812/timepicker-nullpointerexception-on-ics