java - codeEt.setText(extras.getString ("code"));导致 NullPointerException

如何解决以下源代码第 48 行上的 NullPointerException:

   codeEt.setText(extras.getString("code"));

我已经仔细查看了这部分代码，但似乎无法解决该问题。该变量似乎在任何出现的地方都有效。任何输入/先进知识都将不胜感激。

查看国家 java :

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.database.Cursor;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.TextView;
import android.widget.TimePicker;

public class ViewCountry extends Activity {

       private long rowID;
       private TextView nameTv;
       private TextView capTv;
       private TextView codeTv; 
       private TextView timeTv; 

       @Override
       public void onCreate(Bundle savedInstanceState) 
       {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.view_country);

          setUpViews();
          Bundle extras = getIntent().getExtras();
          rowID = extras.getLong(CountryList.ROW_ID); 
       }

       private void setUpViews() {
           nameTv = (TextView) findViewById(R.id.nameText);
           capTv = (TextView) findViewById(R.id.capText);
           timeTv = (TextView) findViewById(R.id.timeEdit);
           codeTv = (TextView) findViewById(R.id.codeText);
       }

       @Override
       protected void onResume()
       {
          super.onResume();
          new LoadContacts().execute(rowID);
       } 

       private class LoadContacts extends AsyncTask<Long, Object, Cursor> 
       {
          DatabaseConnector dbConnector = new DatabaseConnector(ViewCountry.this);

          @Override
          protected Cursor doInBackground(Long... params)
          {
             dbConnector.open();
             return dbConnector.getOneContact(params[0]);
          } 

          @Override
          protected void onPostExecute(Cursor result)
          {
             super.onPostExecute(result);

             result.moveToFirst();
             // get the column index for each data item
             int nameIndex = result.getColumnIndex("name");
             int capIndex = result.getColumnIndex("cap");
             int codeIndex = result.getColumnIndex("code");
             int timeIndex = result.getColumnIndex("time");

             nameTv.setText(result.getString(nameIndex));
             capTv.setText(result.getString(capIndex));
//           timeTv.setText(result.getInt(timeIndex)); // <--- HERE WAS AN ERROR
             timeTv.setText(result.getString(timeIndex)); // time was stored as Sting all the time
             codeTv.setText(result.getString(codeIndex));

             result.close();
             dbConnector.close();
          }
       } 


       @Override
       public boolean onCreateOptionsMenu(Menu menu) 
       {
          super.onCreateOptionsMenu(menu);
          MenuInflater inflater = getMenuInflater();
          inflater.inflate(R.menu.view_country_menu, menu);
          return true;
       }

       @Override
       public boolean onOptionsItemSelected(MenuItem item) 
       {
          switch (item.getItemId())
          {
             case R.id.editItem:
                Intent addEditContact =
                   new Intent(this, AddEditDevice.class);

                addEditContact.putExtra(CountryList.ROW_ID, rowID);
                addEditContact.putExtra("name", nameTv.getText());
                addEditContact.putExtra("cap", capTv.getText());
                addEditContact.putExtra("code", codeTv.getText());
                startActivity(addEditContact); 
                return true;

             case R.id.deleteItem:
                deleteContact();
                return true;

             default:
                return super.onOptionsItemSelected(item);
          } 
       }

       private void deleteContact()
       {

          AlertDialog.Builder alert = new AlertDialog.Builder(ViewCountry.this);

          alert.setTitle(R.string.confirmTitle); 
          alert.setMessage(R.string.confirmMessage); 

          alert.setPositiveButton(R.string.delete_btn,
             new DialogInterface.OnClickListener()
             {
                public void onClick(DialogInterface dialog, int button)
                {
                   final DatabaseConnector dbConnector = 
                      new DatabaseConnector(ViewCountry.this);

                   AsyncTask<Long, Object, Object> deleteTask =
                      new AsyncTask<Long, Object, Object>()
                      {
                         @Override
                         protected Object doInBackground(Long... params)
                         {
                            dbConnector.deleteContact(params[0]); 
                            return null;
                         } 

                         @Override
                         protected void onPostExecute(Object result)
                         {
                            finish(); 
                         }
                      };

                   deleteTask.execute(new Long[] { rowID });               
                }
             }
          );

          alert.setNegativeButton(R.string.cancel_btn, null).show();
       }
    }

查看国家/地区 XML:

<?xml version="1.0" encoding="utf-8"?>

<TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent" 
android:layout_height="wrap_content"
android:stretchColumns="1" 
android:layout_margin="5dp">
<TableRow>         
  <TextView 
    style="@style/StyleLabel"
    android:text="@string/name_lbl"/>
 <TextView 
    android:id="@+id/nameText" 
    style="@style/StyleText"/>         
 </TableRow>

 <TableRow>         
 <TextView 
    style="@style/StyleLabel"
    android:text="@string/cap_lbl"/>         
 <TextView 
    android:id="@+id/capText"
    style="@style/StyleText"/>         
 </TableRow>

  <TableRow>       
  <TextView 
    style="@style/StyleLabel"
    android:text="Time Limit"/>                    
 <TextView 
    android:id="@+id/timeText"
    style="@style/StyleText"/>         
 </TableRow>
 <TableRow>         
 <TextView 
    style="@style/StyleLabel"
    android:text="Linked Users"/>         
 <TextView 
android:id="@+id/codeText"
    style="@style/StyleText"/>         
 </TableRow>
 <TableRow>         
 <TextView 
    style="@style/StyleLabel"
    android:text="@string/_lbl"/>         
 <TextView 
    android:id="@+id/timeEdit"
    style="@style/StyleText"/>  

</TableRow>
<TableRow>         
 <TextView 
    style="@style/StyleLabel"
    android:text="@string/code_lbl"/>         
 <TextView 
    android:id="@+id/codeEdit"
    style="@style/StyleText"/>  

</TableRow>


</TableLayout>

添加编辑设备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 java.text.DecimalFormat;


public class AddEditDevice extends Activity {

     private long rowID; 
     private EditText nameEt;
     private EditText capEt;
     private EditText codeEt;
     private TimePicker timeEt;
    // DecimalFormat df =   new DecimalFormat  ("00");
    // public String minutes = df.format(min);


      // @Override
       public void onCreate(Bundle savedInstanceState) 
       {
          super.onCreate(savedInstanceState); 
          setContentView(R.layout.add_country);

          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"));    
             String time = extras.getString("time");
             String[] parts = time.split(":");
             timeEt.setCurrentHour(Integer.valueOf(parts[0]));
             timeEt.setCurrentMinute(Integer.valueOf(parts[1]));
             timeEt.setIs24HourView(false);


          }

          Button saveButton =(Button) findViewById(R.id.saveBtn);
          saveButton.setOnClickListener(new OnClickListener() {

              public void onClick(View v) 
              {
                 if (nameEt.getText().length() != 0)
                 {
                    AsyncTask<Object, Object, Object> saveContactTask = 
                       new AsyncTask<Object, Object, Object>() 
                       {
                          @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(AddEditDevice.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() + ":"
                              + timeEt.getCurrentMinute().toString(),
                          codeEt.getText().toString());

              }
              else
              {
                 dbConnector.updateContact(rowID,
                         nameEt.getText().toString(),
                            capEt.getText().toString(),
                              timeEt.getCurrentHour().toString() + ":"
                                  + timeEt.getCurrentMinute().toString(),
                              codeEt.getText().toString());
              }
           }
}

添加编辑设备 XML:

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="fill_parent" 
   android:layout_height="wrap_content" android:layout_weight="1">

   <LinearLayout android:id="@+id/linearLayout"
      android:layout_width="fill_parent"
      android:layout_height="wrap_content"
      android:orientation="vertical" 
      android:padding="5dp">

      <EditText android:id="@+id/nameEdit"
         android:layout_width="fill_parent"
         android:layout_height="wrap_content" 
         android:imeOptions="actionNext" 
         android:hint="@string/name_hint"
         android:inputType="textPersonName|textCapWords"/>

      <EditText android:id="@+id/capEdit"
         android:layout_width="fill_parent" 
         android:layout_height="wrap_content" 
         android:imeOptions="actionNext" 
         android:hint="@string/cap_hint"
         android:inputType="textPersonName|textCapWords"/>

    <TextView
        android:id="@+id/textView3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Data Limit"
        android:textColor="#ffffff"
        android:textAppearance="?android:textAppearanceMedium" />

    <SeekBar
        android:id="@+id/seekBar1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1.0"
            android:gravity="left"
            android:textColor="#ffffff"
            android:text="10MB" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1.0"
            android:gravity="right"
            android:textColor="#ffffff"
            android:text="Unlimited Data" />
    </LinearLayout>

    <TextView
        android:id="@+id/textView3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Bandwidth Limit"
        android:textColor="#ffffff"
        android:textAppearance="?android:textAppearanceMedium" />

    <SeekBar
        android:id="@+id/seekBar1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1.0"
            android:gravity="left"
            android:textColor="#ffffff"
            android:text="10kbs" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1.0"
            android:textColor="#ffffff"
            android:gravity="right"
            android:text="Unlimited Bandwidth" />
    </LinearLayout>

    <TextView
        android:id="@+id/TextView02"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:textAppearanceSmall" />

    <TextView
        android:id="@+id/TextView02"
        android:layout_width="wrap_content"
        android:layout_gravity="center"
        android:layout_weight="1.0"
        android:layout_height="wrap_content"
        android:text="WiFi Time Limit"
        android:layout_marginBottom="8dp"
        android:textColor="#ffffff"
        android:textAppearance="?android:textAppearanceMedium" />

    <TimePicker
        android:id="@+id/timeEdit"
        android:layout_width="286dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_weight="1.0"

        android:gravity="center" />

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Parental Controls"
          android:layout_gravity="center"
        android:gravity="center"
        android:textAppearance="?android:attr/textAppearanceMedium" />

 <LinearLayout
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
     android:orientation="horizontal" 
         android:layout_gravity="center"
        android:gravity="center">

     <ToggleButton
         android:id="@+id/ToggleButton01"
         android:layout_width="199dp"
         android:layout_height="wrap_content"
         android:gravity="center"
         android:text="ToggleButton" />

     <ToggleButton
         android:id="@+id/toggleButton1"
         android:layout_width="199dp"
         android:layout_height="wrap_content"
         android:gravity="center"
         android:text="ToggleButton" />

</LinearLayout>



<LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1.0"
            android:gravity="left"
            android:textColor="#ffffff"
            android:text="IPv4 SPI Firewall Protection" />


        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1.0"
            android:textColor="#ffffff"
            android:gravity="right"
            android:text="IPv6 SPI Firewall Protection" />
    </LinearLayout>


<LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:orientation="horizontal" >

    <ToggleButton
        android:id="@+id/ToggleButton03"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_weight="1.0"
        android:gravity="center"
        android:text="ToggleButton" />

    <ToggleButton
        android:id="@+id/ToggleButton02"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_weight="1.0"
        android:gravity="center"
        android:text="ToggleButton" />

    </LinearLayout>

         <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:gravity="left"
        android:orientation="horizontal" >
         />


</LinearLayout>
    <EditText
        android:id="@+id/codeEdit"
        android:inputType="textUri"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:ems="10"
        android:lines="1"
        android:hint="@string/code_hint"
        android:imeOptions="actionNext" />

      <Button
          android:id="@+id/saveBtn"
          android:layout_width="199dp"
          android:layout_height="wrap_content"
          android:layout_gravity="center_horizontal"
          android:layout_marginTop="15dp"
          android:text="@string/save_btn" />

   </LinearLayout>
</ScrollView>

日志:

最佳答案

嗯，我认为您的布局文件中没有 ID 为 codeEdit 的 Edittext，这可能是错误的原因。

关于java - codeEt.setText(extras.getString ("code"));导致 NullPointerException，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/15715085/

java - codeEt.setText(extras.getString ("code"));导致 NullPointerException

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