Java Button的new setText属性上无原因出现Nullpointer异常
这只是我的应用程序中一个活动的代码,它的基本功能是,根据它提供的紧急情况下要联系的人员列表的位置而定。然而,我最近收到一些新数据要添加到应用程序中,现在我不得不在布局中添加几个按钮(最初只有2个按钮),出于某种原因,我在添加的新按钮上出现了nullpointer异常。这是没有意义的,为什么我得到这样一个例外,因为我相信我已经初始化按钮正确。任何帮助都将不胜感激 Contacts.javaJava Button的new setText属性上无原因出现Nullpointer异常,java,android,nullpointerexception,null,Java,Android,Nullpointerexception,Null,这只是我的应用程序中一个活动的代码,它的基本功能是,根据它提供的紧急情况下要联系的人员列表的位置而定。然而,我最近收到一些新数据要添加到应用程序中,现在我不得不在布局中添加几个按钮(最初只有2个按钮),出于某种原因,我在添加的新按钮上出现了nullpointer异常。这是没有意义的,为什么我得到这样一个例外,因为我相信我已经初始化按钮正确。任何帮助都将不胜感激 Contacts.java import android.net.Uri; import android.support.v7.app.
import android.net.Uri;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.content.Intent;
import android.widget.Button;
import android.view.View;
import android.widget.TextView;
import android.widget.RelativeLayout;
public class Contacts extends ActionBarActivity {
Button bt1;
Button bt2;
Button bt3;
Button bt4;
Button bt5;
Button bt6;
TextView t1;
TextView t2;
TextView t3;
TextView t4;
TextView t5;
TextView t6;
private String num1;
private String num2;
private String num3;
private String num4;
private String num5;
private String num6;
// RelativeLayout myLayout;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_contacts);
Intent intent = getIntent();
Bundle extras = intent.getExtras();
String branch = extras.getString("branch");
String level = extras.getString("level");
bt1 = (Button) findViewById(R.id.contact_button1);
bt2 = (Button) findViewById(R.id.contact_button2);
bt3 = (Button) findViewById(R.id.contact_button3);
bt4 = (Button) findViewById(R.id.contact_button4);
bt5 = (Button) findViewById(R.id.contact_button5);
bt6 = (Button) findViewById(R.id.contact_button6);
t1 = (TextView) findViewById(R.id.textView1);
t2 = (TextView) findViewById(R.id.textView2);
t3 = (TextView) findViewById(R.id.textView3);
t4 = (TextView) findViewById(R.id.textView4);
t5 = (TextView) findViewById(R.id.textView5);
t6 = (TextView) findViewById(R.id.textView6);
if(branch.contentEquals("Hoody") && level.contentEquals("Safety In Charge"))
{
bt1.setText("Javaji P");
bt2.setText("H S Rao");
bt3.setText("Sunil KB");
bt4.setText("K Kishor");
bt5.setText("Vincent");
bt6.setText("Sreenivas K");
num1 = "+919845956099";
num2 = "+919686198661";
num3 = "+919880141599";
num4 = "+919880185109";
num5 = "+919844303344";
num6 = "+919880598205";
}
if(branch.contentEquals("Hoody") && level.contentEquals("Fire/Accident/Ambulance"))
{
bt1.setText("Security");
bt2.setVisibility(View.GONE);
bt3.setVisibility(View.GONE);
bt4.setVisibility(View.GONE);
bt5.setVisibility(View.GONE);
bt6.setVisibility(View.GONE);
// t1.setVisibility(View.GONE);
// t2.setVisibility(View.GONE);
/// t3.setVisibility(View.GONE);
// t4.setVisibility(View.GONE);
// t5.setVisibility(View.GONE);
// t6.setVisibility(View.GONE);
num1 = "08022979333";
}
if(branch.contentEquals("Hoody") && level.contentEquals("Emergency Declarer"))
{
bt1.setText("B S Lokeshwaran(Head-Admin)");
bt2.setText("Philip Mammen(Head-HR)");
bt3.setVisibility(View.GONE);
bt4.setVisibility(View.GONE);
bt5.setVisibility(View.GONE);
bt6.setVisibility(View.GONE);
// t1.setVisibility(View.GONE);
// t2.setVisibility(View.GONE);
// t3.setVisibility(View.GONE);
// t4.setVisibility(View.GONE);
// t5.setVisibility(View.GONE);
// t6.setVisibility(View.GONE);
num1 = "+919741144114";
num2 = "+919880141779";
}
if(branch.contentEquals("BTP") && level.contentEquals("Safety In Charge"))
{
bt1.setText("Javaji P");
bt2.setText("H S Rao");
bt3.setText("Sunil KB");
bt4.setText("K Kishor");
bt5.setText("Roshan");
bt6.setText("Varghese M");
num1 = "+919845956099";
num2 = "+919686198661";
num3 = "+919880141599";
num4 = "+919880185109";
num5 = "+919945729472";
num6 = "+919880114562";
}
if(branch.contentEquals("BTP") && level.contentEquals("Fire/Accident/Ambulance"))
{
bt1.setText("Security");
bt2.setVisibility(View.GONE);
bt3.setVisibility(View.GONE);
bt4.setVisibility(View.GONE);
bt5.setVisibility(View.GONE);
bt6.setVisibility(View.GONE);
num1 = "08022984000";
}
if(branch.contentEquals("BTP") && level.contentEquals("Emergency Declarer"))
{
bt1.setText("B S Lokeshwaran(Head-Admin)");
bt2.setText("Philip Mammen(Head-HR)");
bt3.setVisibility(View.GONE);
bt4.setVisibility(View.GONE);
bt5.setVisibility(View.GONE);
bt6.setVisibility(View.GONE);
num1 = "+919741144114";
num2 = "+919880141779";
}
if(branch.contentEquals("TD") && level.contentEquals("Safety In Charge"))
{
bt1.setText("Javaji P");
bt2.setText("H S Rao");
bt3.setText("Sunil KB");
bt4.setText("K Kishor");
bt5.setText("Anitha S");
bt6.setText("Sreenivas K");
num1 = "+919845956099";
num2 = "+919686198661";
num3 = "+919880141599";
num4 = "+919880185109";
num5 = "+919980299033";
num6 = "+919880598205";
}
if(branch.contentEquals("TD") && level.contentEquals("Fire/Accident/Ambulance"))
{
bt1.setText("Security");
bt2.setVisibility(View.GONE);
bt3.setVisibility(View.GONE);
bt4.setVisibility(View.GONE);
bt5.setVisibility(View.GONE);
bt6.setVisibility(View.GONE);
num1 = "08022979761";
}
if(branch.contentEquals("TD") && level.contentEquals("Emergency Declarer"))
{
bt1.setText("B S Lokeshwaran(Head-Admin)");
bt2.setText("Philip Mammen(Head-HR)");
bt3.setVisibility(View.GONE);
bt4.setVisibility(View.GONE);
bt5.setVisibility(View.GONE);
bt6.setVisibility(View.GONE);
num1 = "+919741144114";
num2 = "+919880141779";
}
if((branch.contentEquals("Neyyar") && level.contentEquals("Safety In Charge")) || (branch.contentEquals("Leela") && level.contentEquals("Safety In Charge")) || (branch.contentEquals("Gayathri") && level.contentEquals("Safety In Charge")))
{
bt1.setText("Tony");
bt2.setText("Jossy Joseph");
num1 = "+919745818995";
num2 = "+919961528687";
}
if((branch.contentEquals("Neyyar")||branch.contentEquals("Leela")|| branch.contentEquals("Gayathri")) && level.contentEquals("Fire/Accident/Ambulance"))
{
bt1.setText("Security");
bt2.setVisibility(View.GONE);
num1 = "04716661000";
}
if((branch.contentEquals("Neyyar")||branch.contentEquals("Leela")|| branch.contentEquals("Gayathri")) && level.contentEquals("Emergency Declarer"))
{
bt1.setText("Sreekumar.V(Centre Head)");
bt2.setText("Ajish MJ(Head-HR)");
num1 = "+919846022266";
num2 = "+919895806075";
}
if(branch.contentEquals("Chennai") && level.contentEquals("Safety In Charge"))
{
bt1.setText("Meeran");
bt2.setVisibility(View.GONE);
num1 = "+919884515288";
}
if(branch.contentEquals("Chennai") && level.contentEquals("Fire/Accident/Ambulance"))
{
bt1.setText("Security");
bt2.setVisibility(View.GONE);
num1 = "08022979761";
}
if(branch.contentEquals("Chennai") && level.contentEquals("Emergency Declarer"))
{
bt1.setText("Jayendran.G(Center Head)");
bt2.setVisibility(View.GONE);
num1 = "+919840385745";
}
if((branch.contentEquals("Alpha 1 & 2") || branch.contentEquals("SEZ")) && level.contentEquals("Safety In Charge"))
{
bt1.setText("Laxman Jadhav");
bt2.setVisibility(View.GONE);
num1 = "+919689887857";
}
if((branch.contentEquals("Alpha 1 & 2") || branch.contentEquals("SEZ")) && level.contentEquals("Fire/Accident/Ambulance"))
{
bt1.setText("Security");
bt2.setVisibility(View.GONE);
bt3.setVisibility(View.GONE);
bt4.setVisibility(View.GONE);
bt5.setVisibility(View.GONE);
bt6.setVisibility(View.GONE);
num1 = "02066060033";
}
if((branch.contentEquals("Alpha 1 & 2") || branch.contentEquals("SEZ")) && level.contentEquals("Emergency Declarer"))
{
bt1.setText("Mr.Vasant Shah(Center Head)");
bt2.setText("Ms.Simrit Dhindasa(Sr.Executive-HR)");
num1 = "+919503838082";
num2 = "+919921183320";
}
if(branch.contentEquals("Mumbai") && level.contentEquals("Safety In Charge"))
{
bt1.setText("Naveen Dighe");
bt2.setVisibility(View.GONE);
num1 = "+919821142863";
}
if(branch.contentEquals("Mumbai") && level.contentEquals("Emergency Declarer"))
{
bt1.setText("Nagarajan(Center Head)");
bt2.setVisibility(View.GONE);
num1 = "+919967723450";
}
if(branch.contentEquals("Mumbai") && level.contentEquals("Fire/Accident/Ambulance"))
{
bt1.setText("Security");
bt2.setVisibility(View.GONE);
num1 = "0226822145";
}
}
public void launchDialer(String number)
{
String numberToDial = "tel:"+number;
startActivity(new Intent(Intent.ACTION_DIAL, Uri.parse(numberToDial)));
}
public void onClickbt1(View view)
{
launchDialer(num1);
}
public void onClickbt2(View view)
{
launchDialer(num2);
}
public void onClickbt3(View view)
{
launchDialer(num3);
}
public void onClickbt4(View view)
{
launchDialer(num4);
}
public void onClickbt5(View view)
{
launchDialer(num5);
}
public void onClickbt6(View view)
{
launchDialer(num6);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_contacts, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
activity_contacts.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context="com.prashanth.emergencycontacts.Contacts"
android:background="@drawable/bg"
android:id="@+id/layout1">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="CONTACT 1"
android:id="@+id/contact_button1"
android:onClick="onClickbt1"
android:background="@android:drawable/dialog_holo_light_frame"
android:layout_alignParentTop="true"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="CONTACT 2"
android:id="@+id/contact_button2"
android:layout_marginTop="40dp"
android:onClick="onClickbt2"
android:background="@android:drawable/dialog_holo_light_frame"
android:layout_below="@+id/contact_button1"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:layout_alignLeft="@+id/contact_button1"
android:layout_alignStart="@+id/contact_button1" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="CONTACT 3"
android:id="@+id/contact_button3"
android:onClick="onClickbt3"
android:layout_marginTop="40dp"
android:layout_below="@+id/contact_button2"
android:layout_alignLeft="@+id/contact_button2"
android:layout_alignStart="@+id/contact_button2"
android:layout_alignRight="@+id/contact_button2"
android:layout_alignEnd="@+id/contact_button2"
android:background="@android:drawable/dialog_holo_light_frame" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="CONTACT 4"
android:id="@+id/contact_button4"
android:onClick="onClickbt4"
android:layout_below="@+id/contact_button3"
android:layout_alignLeft="@+id/contact_button3"
android:layout_alignStart="@+id/contact_button3"
android:layout_marginTop="40dp"
android:layout_alignRight="@+id/contact_button3"
android:layout_alignEnd="@+id/contact_button3"
android:background="@android:drawable/dialog_holo_light_frame" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="CONTACT 5"
android:id="@+id/contact_button5"
android:onClick="onClickbt5"
android:layout_below="@+id/contact_button4"
android:layout_alignLeft="@+id/contact_button4"
android:layout_alignStart="@+id/contact_button4"
android:layout_marginTop="40dp"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:background="@android:drawable/dialog_holo_light_frame" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="CONTACT 6"
android:id="@+id/contact_button6"
android:onClick="onClickbt6"
android:layout_below="@+id/contact_button5"
android:layout_alignLeft="@+id/contact_button5"
android:layout_alignStart="@+id/contact_button5"
android:layout_marginTop="40dp"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:background="@android:drawable/dialog_holo_light_frame" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Security"
android:id="@+id/textView1"
android:layout_above="@+id/contact_button2"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Health & Safety"
android:id="@+id/textView2"
android:layout_alignBottom="@+id/contact_button2"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Transport"
android:id="@+id/textView3"
android:layout_above="@+id/contact_button4"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Maintenance"
android:id="@+id/textView4"
android:layout_alignBottom="@+id/contact_button4"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Housekeeping"
android:id="@+id/textView5"
android:layout_alignBottom="@+id/contact_button5"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="IT"
android:id="@+id/textView6"
android:layout_alignBottom="@+id/contact_button6"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
</RelativeLayout>
任何帮助都将不胜感激 碰撞日志清楚地告诉我们出了什么问题
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setText(java.lang.CharSequence)' on a null object reference
at com.prashanth.emergencycontacts.Contacts.onCreate(Contacts.java:65)
您正试图在一个为空的按钮上调用setText()
。它还告诉你它在哪条线上崩溃
Contacts.onCreate(Contacts.java:65)
也就是说,你需要检查第65行。第65行是
bt1.setText("Javaji P");
iebt1
为null
。但是您在下一行中找到了前面的bt1
bt1 = (Button) findViewById(R.id.contact_button1);
这意味着bt1
不存在于activity\u contacts.xml
版面中,或者idcontact\u按钮1
错误
请尝试了解崩溃日志是如何工作的,因为这是一个非常基本的崩溃,您应该知道如何快速修复它。在布局文件中,您指的是带有@+id的现有元素id,例如:
android:layout_alignLeft=“@+id/联系人_按钮1”
创建新id时应使用@+id。引用已创建的id时使用@id,例如:
android:layout_alignLeft=“@id/contact_button1”在异常中清楚地提到了行号。你检查过了吗?我彻底检查了行号和xml文件,我不知道为什么按钮指向空!这是我做的第一件事。我检查了第#65行,我知道我已经正确初始化了按钮,并且它们存在于xml文件中。这是没有意义的,为什么我得到这个错误,因为按钮存在,并已初始化!第65行指向bt3.setText(“Sunil KB”);如果我使用除bt1和bt2之外的所有按钮对代码行进行注释,应用程序将正常运行。出于某种奇怪的原因,它显示了所有按钮bt3到bt6的错误。
bt1 = (Button) findViewById(R.id.contact_button1);