使用spinner，程序运行就崩溃，请帮忙看看。

Question

版本2.2，XLM文件里这样定义    <Spinner android:id="@+id/feet"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"    
        android:drawSelectorOnTop="true"
        android:prompt="@string/feet_prompt"
    />JAVA代码如下
        private Spinner field_feet;        field_feet = (Spinner)findViewById(R.id.feet);        Log.d(TAG,"field_feet 0");
        ArrayAdapter<CharSequence> adapter_feet = ArrayAdapter.createFromResource(
         this, R.array.feets, android.R.layout.simple_spinner_item);
            
        Log.d(TAG,"field_feet 1");
        adapter_feet.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);        Log.d(TAG,"field_feet 2");
        field_feet.setAdapter(adapter_feet);        程序log里，出现这条后，就没有下面的信息了。运行显示崩溃了。
        Log.d(TAG,"field_feet 0");请各位帮忙看看哪里有问题呢？

Answer 1

发详细的出错Log信息上来，在LogCat的E标签里面有错误信息

Answer 2

贴错误log，或者贴全部代码。
目测setconentview的问题。

Answer 3

log如下，请大侠帮忙看看哪里出问题了。07-23 09:53:43.705: D/aBmi(313): setContentView
07-23 09:53:43.825: D/aBmi(313): findviews
07-23 09:53:43.825: D/aBmi(313): findViewById
07-23 09:53:43.845: D/aBmi(313): field_feet 0
07-23 09:53:43.845: D/AndroidRuntime(313): Shutting down VM
07-23 09:53:43.845: W/dalvikvm(313): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
07-23 09:53:43.885: E/AndroidRuntime(313): FATAL EXCEPTION: main
07-23 09:53:43.885: E/AndroidRuntime(313): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.demo.andriod.abmi/com.demo.andriod.abmi.Abmi}: java.lang.NullPointerException
07-23 09:53:43.885: E/AndroidRuntime(313):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
07-23 09:53:43.885: E/AndroidRuntime(313):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
07-23 09:53:43.885: E/AndroidRuntime(313):  at android.app.ActivityThread.access$2300(ActivityThread.java:125)
07-23 09:53:43.885: E/AndroidRuntime(313):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
07-23 09:53:43.885: E/AndroidRuntime(313):  at android.os.Handler.dispatchMessage(Handler.java:99)
07-23 09:53:43.885: E/AndroidRuntime(313):  at android.os.Looper.loop(Looper.java:123)
07-23 09:53:43.885: E/AndroidRuntime(313):  at android.app.ActivityThread.main(ActivityThread.java:4627)
07-23 09:53:43.885: E/AndroidRuntime(313):  at java.lang.reflect.Method.invokeNative(Native Method)
07-23 09:53:43.885: E/AndroidRuntime(313):  at java.lang.reflect.Method.invoke(Method.java:521)
07-23 09:53:43.885: E/AndroidRuntime(313):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
07-23 09:53:43.885: E/AndroidRuntime(313):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
07-23 09:53:43.885: E/AndroidRuntime(313):  at dalvik.system.NativeStart.main(Native Method)
07-23 09:53:43.885: E/AndroidRuntime(313): Caused by: java.lang.NullPointerException
07-23 09:53:43.885: E/AndroidRuntime(313):  at android.content.res.AssetManager.getResourceTextArray(AssetManager.java:213)
07-23 09:53:43.885: E/AndroidRuntime(313):  at android.content.res.Resources.getTextArray(Resources.java:361)
07-23 09:53:43.885: E/AndroidRuntime(313):  at android.widget.ArrayAdapter.createFromResource(ArrayAdapter.java:391)
07-23 09:53:43.885: E/AndroidRuntime(313):  at com.demo.andriod.abmi.Abmi.findViews(Abmi.java:72)
07-23 09:53:43.885: E/AndroidRuntime(313):  at com.demo.andriod.abmi.Abmi.onCreate(Abmi.java:44)
07-23 09:53:43.885: E/AndroidRuntime(313):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
07-23 09:53:43.885: E/AndroidRuntime(313):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
07-23 09:53:43.885: E/AndroidRuntime(313):  ... 11 more
07-23 09:54:28.945: I/Process(313): Sending signal. PID: 313 SIG: 9

Answer 4

代码如下：package com.demo.andriod.abmi;import java.text.DecimalFormat;
import java.util.Locale;import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.res.Configuration;
import android.content.res.Resources;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;public class Abmi extends Activity {
private static final String TAG = "aBmi";

/** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        
        Resources res = getResources();
        Configuration conf = res.getConfiguration();
        conf.locale = Locale.SIMPLIFIED_CHINESE;
        conf.locale = Locale.ENGLISH;
        DisplayMetrics dm = res.getDisplayMetrics();
        res.updateConfiguration(conf, dm);
        
        Log.d(TAG,"setContentView");
        setContentView(R.layout.main);        Log.d(TAG,"findviews");
        findViews();        Log.d(TAG,"setListensers");
        setListensers();
    }    private Button button_calc;
//    private EditText field_feet;
//    private EditText field_inch;
    private Spinner field_feet;
    private Spinner field_inch;
    private EditText field_weight;
    private TextView view_result;
    private TextView view_suggest;       private void findViews(){
        Log.d(TAG,"findViewById");     button_calc = (Button)findViewById(R.id.submit);    
//        field_feet = (EditText)findViewById(R.id.feet);
//        field_inch = (EditText)findViewById(R.id.inch);
        field_feet = (Spinner)findViewById(R.id.feet);
        field_inch = (Spinner)findViewById(R.id.inch);
        field_weight = (EditText)findViewById(R.id.weight);
        view_result = (TextView)findViewById(R.id.result);
        view_suggest = (TextView)findViewById(R.id.suggest);        Log.d(TAG,"field_feet 0");
        ArrayAdapter<CharSequence> adapter_feet = ArrayAdapter.createFromResource(
         this, R.array.feets, android.R.layout.simple_spinner_item);
            
        Log.d(TAG,"field_feet 1");
        adapter_feet.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);        Log.d(TAG,"field_feet 2");
        field_feet.setAdapter(adapter_feet);                Log.d(TAG,"field_inch 0");
        ArrayAdapter<CharSequence> adapter_inch = ArrayAdapter.createFromResource(
         this, R.array.inches, android.R.layout.simple_spinner_item);
            
        Log.d(TAG,"field_inch 1");
        adapter_inch.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);        Log.d(TAG,"field_inch 2");
        field_inch.setAdapter(adapter_inch);
                
    }    //Listen for button clicks
    private void setListensers(){
        Log.d(TAG,"set Listensers");
        
        field_feet.setOnItemSelectedListener(getFeet);
        field_inch.setOnItemSelectedListener(getInch);
        
    button_calc.setOnClickListener(calcUsBMI);    
    }    private int feet;
    private int inch;    private Spinner.OnItemSelectedListener getFeet = new Spinner.OnItemSelectedListener(){
     public void onItemSelected(AdapterView parent, View v, int position, long id) {
            feet = parent.getSelectedItemPosition()+2;    
     }
    
        public void onNothingSelected(AdapterView parent) {
        }
    };    private Spinner.OnItemSelectedListener getInch = new Spinner.OnItemSelectedListener() {
        public void onItemSelected(AdapterView parent, View v, int position, long id) {
                inch = parent.getSelectedItemPosition()+1;
        }
        
        public void onNothingSelected(AdapterView parent) {
        }
    };
     
    private Button.OnClickListener calcUsBMI = new Button.OnClickListener(){
    public void onClick(View v) {
// TODO Auto-generated method stub
    DecimalFormat nf = new DecimalFormat("0.00");
    
    try{
         /*
         double height = (Double.parseDouble(field_feet.getText().toString())*12+Double.parseDouble(field_inch.getText().toString()))*2.54/100;
         */
            double height = (feet*12+inch)*2.54/100;
            double weight = Double.parseDouble(field_weight.getText().toString())*0.45359;
            double BMI = weight / (height * height);
            
            //Present result
            view_result.setText(getText(R.string.bmi_result) + nf.format(BMI));
        
                //Give health advice
                if( BMI > 27 ) {
                 view_suggest.setText(R.string.advice_fat);
                } else if( BMI > 25 ) {
                 view_suggest.setText(R.string.advice_heavy);            
                } else if( BMI < 20 ) {
                 view_suggest.setText(R.string.advice_light);
                } else  {
                 view_suggest.setText(R.string.advice_average);
                } 
        
            } catch(Exception obj){
            Toast.makeText(Abmi.this, R.string.input_error, Toast.LENGTH_SHORT).show();
        }
    }
    };     
    protected static final int MENU_ABOUT = Menu.FIRST;    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
     // TODO Auto-generated method stub
     super.onCreateOptionsMenu(menu);
        Log.d(TAG,"open Menu");
     menu.add(0,MENU_ABOUT,0,R.string.about_label);
     return true;
    }    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
     // TODO Auto-generated method stub
     super.onOptionsItemSelected(item);
        Log.d(TAG,"select Menu Item");
    
     switch(item.getItemId()){
         case MENU_ABOUT:
         openOptionsDialog();
         break;
     }
    
     return true;
    }    
    public void openOptionsDialog() {  
        Log.d(TAG,"open Dialog");
     new AlertDialog.Builder(this)
        .setTitle(R.string.about_title)
        .setMessage(R.string.about_msg)
        .setPositiveButton(R.string.ok_label, new DialogInterface.OnClickListener(){
        public void onClick(
        DialogInterface dialoginterface, int i){
                    }
    })
         .show();
    }
}

Answer 5

 你把 field_feet.setOnItemSelectedListener(getFeet);
  field_inch.setOnItemSelectedListener(getInch);  
放到  field_inch = (Spinner)findViewById(R.id.inch);
  field_weight = (EditText)findViewById(R.id.weight);
  view_result = (TextView)findViewById(R.id.result);
  view_suggest = (TextView)findViewById(R.id.suggest); 下面，我以前写的时候也会报相同的错，因为 field_feet.setOnItemSelectedListener(getFeet); 调用监听很容易报错，又不好找原因，因为监听写的是对的，所以有时候就是换一下格式，或者 有些东西要放到  onCreate（）方法里面的；像得到  id 之类的，如果 你 spinner 较少 建议 直接用 单独给监听   这样不容易报错还好找原因修改 actorSpinner = (Spinner) findViewById(R.id.ActorSpinnerID);
actorSpinner.setSelection(0, false);
actorSpinner.setOnItemSelectedListener(new OnItemSelectedListener() { public void onItemSelected(AdapterView<?> parent, View view,
int position, long id) { spinnerActor = parent.getItemAtPosition(position).toString(); List<Map<String,Object>> actorNum =  ms.findMovieByType(spinnerType,spinnerRegion, spinnerActor,spinnerYear,television,pageNo,numSize);
listmap.clear();
for (Iterator<Map<String, Object>> typeiterator = actorNum.iterator(); typeiterator.hasNext();) {
Map<String, Object> num = typeiterator.next(); Integer numint = (Integer) num.get("moviepic");
String name = (String) num.get("movieName");
String type = (String) num.get("movieyear");
String region = (String) num.get("movieactor");
String actor = (String) num.get("movieregion");
String year = (String) num.get("movietype");
String link = (String) num.get("movietlink");
String jianjie = (String) num.get("jianjie"); //listmap = FileList.findFile(Environment.getExternalStorageDirectory()+"/Pictures/"+numint+".jpg",name,type,region,actor,year,link,jianjie);
listmap = FileList.findFile("/data/data/com.android.testplayer/pictures/"+numint+".jpg",name,type,region,actor,year,link,jianjie);
}
picadapter.notifyDataSetChanged(); 
}
public void onNothingSelected(AdapterView<?> arg0) {
String message = "对不起，没有找到信息...";
Toast.makeText(getApplicationContext(), message, Toast.LENGTH_LONG);
}
});我  按钮 这样写的 ，代码都没错 ，只是 在上面调用  listener   有时候就是不会让通过，不过我现在的是可以通过的，这样调用，你要很注意细节，有时候你没放错它也会 应用 强制停止运行 
private View.OnClickListener listener = new OnClickListener() {

public void onClick(View v) {
Button bt = (Button) v;
switch(bt.getId()){
case R.id.returnsButtonID:
Intent returnIntent = new Intent(MovieActivity.this,MainActivity.class);

startActivity(returnIntent);
listmap.clear();
MovieActivity.this.finish();
break;
case R.id.SouButtonID:
souSuo();
break;
}
}
}; 
以上，只是建议 

Answer 6

ArrayAdapter.createFromResource(
   this, R.array.inches, android.R.layout.simple_spinner_item);
这个出错，找找看R.array.inches是否存在。

Answer 7

我觉得不是这个问题，检查了下，R.array.inches是存在的。另外，如果不存在，编译通过不了吧？

Answer 8

将这段
ArrayAdapter.createFromResource(
this, R.array.inches, android.R.layout.simple_spinner_item);改成：ArrayAdapter.createFromResource(
getActivity().getApplicationContext(), R.array.inches, android.R.layout.simple_spinner_item);试试

Answer 9

  ArrayAdapter<CharSequence> adapter_feet = ArrayAdapter.createFromResource(
  this, R.array.feets, android.R.layout.simple_spinner_item);看调试信息，是这里的问题。
这代码贴的，真难看。
package com.demo.andriod.abmi;import java.text.DecimalFormat;
import java.util.Locale;import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.res.Configuration;
import android.content.res.Resources;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;public class Abmi extends Activity {
private static final String TAG = "aBmi";/** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
    
  Resources res = getResources();
  Configuration conf = res.getConfiguration();
  conf.locale = Locale.SIMPLIFIED_CHINESE;
  conf.locale = Locale.ENGLISH;
  DisplayMetrics dm = res.getDisplayMetrics();
  res.updateConfiguration(conf, dm);
    
  Log.d(TAG,"setContentView");
  setContentView(R.layout.main);  Log.d(TAG,"findviews");
  findViews();  Log.d(TAG,"setListensers");
  setListensers();
  }  private Button button_calc;
// private EditText field_feet;
// private EditText field_inch;
  private Spinner field_feet;
  private Spinner field_inch;
  private EditText field_weight;
  private TextView view_result;
  private TextView view_suggest;     private void findViews(){
  Log.d(TAG,"findViewById");  button_calc = (Button)findViewById(R.id.submit); 
// field_feet = (EditText)findViewById(R.id.feet);
// field_inch = (EditText)findViewById(R.id.inch);
  field_feet = (Spinner)findViewById(R.id.feet);
  field_inch = (Spinner)findViewById(R.id.inch);
  field_weight = (EditText)findViewById(R.id.weight);
  view_result = (TextView)findViewById(R.id.result);
  view_suggest = (TextView)findViewById(R.id.suggest);  Log.d(TAG,"field_feet 0");
  ArrayAdapter<CharSequence> adapter_feet = ArrayAdapter.createFromResource(
  this, R.array.feets, android.R.layout.simple_spinner_item);
    
  Log.d(TAG,"field_feet 1");
  adapter_feet.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);  Log.d(TAG,"field_feet 2");
  field_feet.setAdapter(adapter_feet);     Log.d(TAG,"field_inch 0");
  ArrayAdapter<CharSequence> adapter_inch = ArrayAdapter.createFromResource(
  this, R.array.inches, android.R.layout.simple_spinner_item);
    
  Log.d(TAG,"field_inch 1");
  adapter_inch.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);  Log.d(TAG,"field_inch 2");
  field_inch.setAdapter(adapter_inch);
    
  }  //Listen for button clicks
  private void setListensers(){
  Log.d(TAG,"set Listensers");
    
  field_feet.setOnItemSelectedListener(getFeet);
  field_inch.setOnItemSelectedListener(getInch);
    
button_calc.setOnClickListener(calcUsBMI); 
  }  private int feet;
  private int inch;  private Spinner.OnItemSelectedListener getFeet = new Spinner.OnItemSelectedListener(){
  public void onItemSelected(AdapterView parent, View v, int position, long id) {
  feet = parent.getSelectedItemPosition()+2; 
  }
  
  public void onNothingSelected(AdapterView parent) {
  }
  };  private Spinner.OnItemSelectedListener getInch = new Spinner.OnItemSelectedListener() {
  public void onItemSelected(AdapterView parent, View v, int position, long id) {
  inch = parent.getSelectedItemPosition()+1;
  }
    
  public void onNothingSelected(AdapterView parent) {
  }
  };
    
  private Button.OnClickListener calcUsBMI = new Button.OnClickListener(){
public void onClick(View v) {
// TODO Auto-generated method stub
DecimalFormat nf = new DecimalFormat("0.00");
  
try{
  /*
  double height = (Double.parseDouble(field_feet.getText().toString())*12+Double.parseDouble(field_inch.getText().toString()))*2.54/100;
  */
  double height = (feet*12+inch)*2.54/100;
  double weight = Double.parseDouble(field_weight.getText().toString())*0.45359;
  double BMI = weight / (height * height);
    
  //Present result
  view_result.setText(getText(R.string.bmi_result) + nf.format(BMI));
    
  //Give health advice
  if( BMI > 27 ) {
  view_suggest.setText(R.string.advice_fat);
  } else if( BMI > 25 ) {
  view_suggest.setText(R.string.advice_heavy); 
  } else if( BMI < 20 ) {
  view_suggest.setText(R.string.advice_light);
  } else {
  view_suggest.setText(R.string.advice_average);
  }  
    
} catch(Exception obj){
Toast.makeText(Abmi.this, R.string.input_error, Toast.LENGTH_SHORT).show();
}
}
  };     
  protected static final int MENU_ABOUT = Menu.FIRST;  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
  // TODO Auto-generated method stub
  super.onCreateOptionsMenu(menu);
  Log.d(TAG,"open Menu");
  menu.add(0,MENU_ABOUT,0,R.string.about_label);
  return true;
  }  @Override
  public boolean onOptionsItemSelected(MenuItem item) {
  // TODO Auto-generated method stub
  super.onOptionsItemSelected(item);
  Log.d(TAG,"select Menu Item");
  
  switch(item.getItemId()){
  case MENU_ABOUT:
  openOptionsDialog();
  break;
  }
  
  return true;
  }    
  public void openOptionsDialog() { 
  Log.d(TAG,"open Dialog");
  new AlertDialog.Builder(this)
.setTitle(R.string.about_title)
.setMessage(R.string.about_msg)
.setPositiveButton(R.string.ok_label, new DialogInterface.OnClickListener(){
public void onClick(
DialogInterface dialoginterface, int i){
  }
})
  .show();
  }
}

Answer 10

改成这样，第一句加上没有问题，第二句只要一加上，程序运行就崩溃。ArrayAdapter<CharSequence> adapter_feet = null;adapter_feet.createFromResource(this, R.array.feets, android.R.layout.simple_spinner_item);请教下，spinner使用上，有什么特别的吗？哪位好心的大大侠，给贴个运行没有问题的spinner的例子？万分感谢了。

Answer 11

String[] pageStrArray = new String[]{"a","b"};
Spinner spinnerPages = new Spinner(this);
ArrayAdapter<String> adapter= new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, pageStrArray); 
spinnerPages.setAdapter(adapter);

Answer 12

请教下，上面的用法，new的时候分配了空间了，对吗？下面这个用法，就是createFromResource，也会分配空间吗？是不是没有分配空间，导致的问题？ArrayAdapter<CharSequence> adapter_feet = ArrayAdapter.createFromResource(
         this, R.array.feets, android.R.layout.simple_spinner_item);

Answer 13

需要用字符型的，ArrayAdapter<CharSequence>，请教怎么用？这样的用法只有两个参数，怎么把R.array.feets的值赋值给adapter_feet呢？ArrayAdapter<CharSequence> adapter_feet= new ArrayAdapter<CharSequence>(this, android.R.layout.simple_spinner_item);