nullpointerexception

问题 This question's answers are a community effort . Edit existing answers to improve this post. It is not currently accepting new answers or interactions. What are Null Pointer Exceptions ( java.lang.NullPointerException ) and what causes them? What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely? 回答1: When you declare a reference variable (i.e. an object) you are really creating a pointer to an object. Consider

问题 I am new in automation. Here is my simple TestNG login code , when I ran the code as TestNG it appears java.lang.NullPointerException and by double clicking it highlights the place where I navigate to the URL. here is my code. enter code here package Day5pkg; import java.util.concurrent.TimeUnit; import org.openqa.selenium.By; import org.openqa.selenium.WebDriver; import org.openqa.selenium.firefox.FirefoxDriver; import org.openqa.selenium.firefox.FirefoxDriver; import org.openqa.selenium

问题 I have nullpointerexception in last line of my oncreate method public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); requestWindowFeature(Window.FEATURE_NO_TITLE); setContentView(R.layout.blindassistantmain); getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); BlindTableLayout tableLayout = (BlindTableLayout) findViewById(R.id.blindTableLayout); BlindButton btn = (BlindButton) findViewById(R.id

问题 i have an activity with 4 fragments from fragment number 1 I want to enable an existing button (that is disable) on fragment 3, when i click in my button in fragment1. this is my attempt: fragment 1: public class FragmentEvolucion extends Fragment { //btnGuardar is in fragment1, the others are in fragment 3 and 4 Button btnGuardar, btnHabilitarMed, btnHabilitarImc; @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View rootView =

问题 i have an activity with 4 fragments from fragment number 1 I want to enable an existing button (that is disable) on fragment 3, when i click in my button in fragment1. this is my attempt: fragment 1: public class FragmentEvolucion extends Fragment { //btnGuardar is in fragment1, the others are in fragment 3 and 4 Button btnGuardar, btnHabilitarMed, btnHabilitarImc; @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View rootView =

问题 I have Parse initialization in a class named (ParseInitialization.java) that extends Application and while running my application (MainActivity.java) I got a RuntimeException and whene I call Parse.initialize inside onCreate in (MainActivity.java) I got a NullpointException here is my code: MainActivity.java package com.example.baharat2; import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener;

问题 I have Parse initialization in a class named (ParseInitialization.java) that extends Application and while running my application (MainActivity.java) I got a RuntimeException and whene I call Parse.initialize inside onCreate in (MainActivity.java) I got a NullpointException here is my code: MainActivity.java package com.example.baharat2; import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener;

问题 I am having a script force close only when i debug on higher API : 16 , But it is working fine when it come to an API : 10. Could it be my project setup problem? It is a simple request to a server to get list of category in a fragment. gallery.java public class gallery extends Fragment { JSONArray jArray; String result = null; InputStream is = null; StringBuilder sb = null; private ListView storeList; @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle

问题 i'm trying to display new fragment with TabBar and View Pager after click on the Navigation drawer item. Problem is that newly created Fragment is causing NULL pointer exception on viewPager.setAdapter(mAdapter); I'm stucked on swipeable-views with tabs in Fragment a several hours but without luck, can somebody helps me with this problem please? For swipable views i followed this tutorial: http://www.androidhive.info/2013/10/android-tab-layout-with-swipeable-views-1/ Code of the fragment is

问题 Here is my email_dialog.xml layout: <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" > <TableRow android:id="@+id/tableRow0" android:layout_width="match_parent" android:layout_height="wrap_content" > </TableRow> <TableRow android:id="@+id/tableRow1" android:layout_width="match_parent" android:layout_height="wrap_content" > <EditText android:id="@+id/txtEmailAddress5"