我在旋转器上遇到麻烦。它曾经奏效，然后上帝知道发生了什么。我认为问题出在微调器选择中的try-catch块中。我在模拟器中运行应用程序，就像我说的，它运行了3天，然后没有。包含代码和日志。谢谢你的帮助。
package com.example.sasquatchdos;
import java.io.*;
import android.os.Bundle;
import android.app.Activity;
import android.text.method.ScrollingMovementMethod;
import android.view.*;
import android.widget.*;
import android.widget.AdapterView.OnItemSelectedListener;
public class MainActivity extends Activity implements OnItemSelectedListener {
//Global variables
private TextView venue_textForm2TextView;
private EditText searchVenueEditText;
private Spinner venueSpinner;
private String selection;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//add searchVenueEditText
searchVenueEditText = (EditText)findViewById(R.id.searchVenueEditTextForm1);
//venueSpinner Setup
//add spinner
venueSpinner = (Spinner) findViewById(R.id.venueSpinner);
//set venueSpinner to the OnSelectedListener
venueSpinner.setOnItemSelectedListener(this);
// Create an ArrayAdapter
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,
R.array.venue_names, android.R.layout.simple_spinner_item);
// Specify layout
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
// Add the adapter to the venueSpinner
venueSpinner.setAdapter(adapter);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
public void searchButtonOnClick(View view){
selection = searchVenueEditText.getText().toString();
//searchVenue button if statement
if (((selection.equals("Bourbon")) | (selection.equals("Bourbon Theater")))){
//change form to view_venue
setContentView(R.layout.venue_text);
//setup TextView on venue_text form
venue_textForm2TextView = (TextView)findViewById(R.id.venue_textForm2TextView);
//create inputStream
InputStream input = getResources().openRawResource(R.raw.venue_bourbon);
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(input));
StringBuilder venueText = new StringBuilder();
try {
String string;
while (( string = bufferedReader.readLine()) != null) {
venueText.append(string);
venueText.append('\n');
venueText.toString();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
venue_textForm2TextView.setMovementMethod( new ScrollingMovementMethod());
venue_textForm2TextView.setText(venueText);
}//end bourbon if statement
if (((selection.equals("Shooters")) | (selection.equals("Sculley's Shooters")))){
//change form to view_venue
setContentView(R.layout.venue_text);
//setup TextView on venue_text form
venue_textForm2TextView = (TextView)findViewById(R.id.venue_textForm2TextView);
//create inputStream
InputStream input = getResources().openRawResource(R.raw.venue_shooters);
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(input));
StringBuilder venueText = new StringBuilder();
try {
String string;
while (( string = bufferedReader.readLine()) != null) {
venueText.append(string);
venueText.append('\n');
venueText.toString();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
venue_textForm2TextView.setMovementMethod( new ScrollingMovementMethod());
venue_textForm2TextView.setText(venueText);
}//end shooters if statement
}//end searchButton onClick
//resetButtonClick
public void resetButtonClick(View view){
//clearSearch button
searchVenueEditText.setText(R.string.search_bar_form_1);
}
//buttonClick for back button on venue_text form
public void backButtonClick(View view){
setContentView(R.layout.main);
}
@Override
public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
//Consulted StackOverflow with problem of finding the position of the spinner
//and setting the setContentView. http://stackoverflow.com/questions/18091984/android-spinner-to-change-setcontentview
TextView textView = (TextView)arg1; //get the position of the spinner and set it to a textView
String spinnerString = textView.getText().toString(); //set textView to a String to use for populating the form with the appropriate file from res/raw
//spinner selection if statements
if (spinnerString.equals("Bourbon Theater")){
//change view
setContentView(R.layout.venue_text);
//create inputStream
InputStream input = getResources().openRawResource(R.raw.venue_bourbon);
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(input));
StringBuilder venueText = new StringBuilder();
try {
String string;
while (( string = bufferedReader.readLine()) != null) {
venueText.append(string);
venueText.append("\n");
venueText.toString();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
venue_textForm2TextView.setMovementMethod( new ScrollingMovementMethod());
venue_textForm2TextView.setText(venueText);
}
if (spinnerString.equals("Shooters")){
//change view
setContentView(R.layout.venue_text);
//create inputStream
InputStream input = getResources().openRawResource(R.raw.venue_shooters);
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(input));
StringBuilder venueText = new StringBuilder();
try {
String string;
while (( string = bufferedReader.readLine()) != null) {
venueText.append(string);
venueText.append("\n");
venueText.toString();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
venue_textForm2TextView.setMovementMethod( new ScrollingMovementMethod());
venue_textForm2TextView.setText(venueText);
// TODO Auto-generated method stub
}
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
}
}
logcat窗口显示：
12-06 00:36:48.295: D/AndroidRuntime(334): Shutting down VM
12-06 00:36:48.325: W/dalvikvm(334): threadid=1: thread exiting with uncaught exception (group=0x40015560)
12-06 00:36:48.365: E/AndroidRuntime(334): FATAL EXCEPTION: main
12-06 00:36:48.365: E/AndroidRuntime(334): java.lang.NullPointerException
12-06 00:36:48.365: E/AndroidRuntime(334): at com.example.sasquatchdos.MainActivity.onItemSelected(MainActivity.java:186)
12-06 00:36:48.365: E/AndroidRuntime(334): at android.widget.AdapterView.fireOnSelected(AdapterView.java:871)
12-06 00:36:48.365: E/AndroidRuntime(334): at android.widget.AdapterView.access$200(AdapterView.java:42)
12-06 00:36:48.365: E/AndroidRuntime(334): at android.widget.AdapterView$SelectionNotifier.run(AdapterView.java:837)
12-06 00:36:48.365: E/AndroidRuntime(334): at android.os.Handler.handleCallback(Handler.java:587)
12-06 00:36:48.365: E/AndroidRuntime(334): at android.os.Handler.dispatchMessage(Handler.java:92)
12-06 00:36:48.365: E/AndroidRuntime(334): at android.os.Looper.loop(Looper.java:123)
12-06 00:36:48.365: E/AndroidRuntime(334): at android.app.ActivityThread.main(ActivityThread.java:3683)
12-06 00:36:48.365: E/AndroidRuntime(334): at java.lang.reflect.Method.invokeNative(Native Method)
12-06 00:36:48.365: E/AndroidRuntime(334): at java.lang.reflect.Method.invoke(Method.java:507)
12-06 00:36:48.365: E/AndroidRuntime(334): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
12-06 00:36:48.365: E/AndroidRuntime(334): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
12-06 00:36:48.365: E/AndroidRuntime(334): at dalvik.system.NativeStart.main(Native Method)
12-06 00:36:51.125: I/Process(334): Sending signal. PID: 334 SIG: 9
答案 0 :(得分：0)
venue_textForm2TextView为空。它没有初始化。
if (((selection.equals("Bourbon")) | (selection.equals("Bourbon Theater")))){
应该更正为，
if (((selection.equals("Bourbon")) || (selection.equals("Bourbon Theater")))){
答案 1 :(得分：0)
在您的微调器的ItemClick中，您设置的是setContentView(R.layout.venue_text);，但您没有初始化venue_textForm2TextView
在ItemClick中添加以下行以初始化venue_textForm2TextView
venue_textForm2TextView = (TextView)findViewById(R.id.venue_textForm2TextView);