如何在以下来源的第 48 行解决 NullPointerException:
codeEt.setText(extras.getString("code"));
我已经上下查看了这部分代码,但似乎无法解决问题。该变量似乎在它出现的任何地方都有效。非常感谢任何输入/高级知识。
查看国家/地区 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>
日志猫: