我试图从Android应用程序中的表单中获取答案。这是我使用的代码：
package com.stage.sondage;
import android.app.Activity;
import android.content.Intent;
import android.database.sqlite.SQLiteException;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.Toast;
public class Questionnaire extends Activity {
//Création d'une instance de ma classe SurveyAdapter
SurveyAdapter survey=new SurveyAdapter(this);
Appreciation appreciation=new Appreciation();
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.questions);
// We get a reference on the radio-group widget
RadioGroup mRadioGroup1 = ( RadioGroup )findViewById( R.appreciation.rep1 );
RadioGroup mRadioGroup2 = ( RadioGroup )findViewById( R.appreciation.rep2 );
RadioGroup mRadioGroup3 = ( RadioGroup )findViewById( R.appreciation.rep3 );
RadioGroup mRadioGroup4 = ( RadioGroup )findViewById( R.appreciation.rep4 );
RadioGroup mRadioGroup5 = ( RadioGroup )findViewById( R.appreciation.rep5 );
RadioButton b1 = (RadioButton)findViewById(mRadioGroup1.getCheckedRadioButtonId());
appreciation.setRep1((String) b1.getText());
RadioButton b2 = (RadioButton)findViewById(mRadioGroup1.getCheckedRadioButtonId());
appreciation.setRep1((String) b2.getText());
RadioButton b3 = (RadioButton)findViewById(mRadioGroup1.getCheckedRadioButtonId());
appreciation.setRep1((String) b3.getText());
RadioButton b4 = (RadioButton)findViewById(mRadioGroup1.getCheckedRadioButtonId());
appreciation.setRep1((String) b4.getText());
RadioButton b5 = (RadioButton)findViewById(mRadioGroup1.getCheckedRadioButtonId());
appreciation.setRep1((String) b5.getText());
EditText zone = (EditText) findViewById(R.appreciation.zone);
appreciation.setZone(zone.getText().toString());
appreciation.setLatitude(0);
appreciation.setLongitude(0);
OnClickListener ButtonEnregistrer = new OnClickListener(){
public void onClick(View actuelView) {
//On ouvre la base de données pour écrire dedans
survey.open();
//On insère le livre que l'on vient de créer
survey.insertAppreciation(appreciation);
//on ferme la base de données
survey.close();
Intent intent = new Intent(Questionnaire.this,Questionnaire.class);
startActivity(intent);
}
};
Button enregistrer = ( Button )findViewById( R.appreciation.enregistrer);
enregistrer.setOnClickListener(ButtonEnregistrer);
}
}
这是调查适配器类的代码：
package com.stage.sondage;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
public class SurveyAdapter {
//nom de la table
public static final String APPRECIATION_TABLE_NAME = "Appreciation";
public static final String COLUMN_IDAPPRECIATION = "IDAPPRECIATIONL";
public static final int NUM_COLUMN_IDAPPRECIATION = 0;
public static final String COLUMN_ZONE = "ZONE";
public static final int NUM_COLUMN_ZONE = 1;
public static final String COLUMN_LATITUDE = "LATITUDE";
public static final int NUM_COLUMN_LATITUDE = 2;
public static final String COLUMN_LONGITUDE = "LONGITUDE";
public static final int NUM_COLUMN_LONGITUDE = 3;
public static final String COLUMN_REP1 = "REP1";
public static final int NUM_COLUMN_REP1 = 4;
public static final String COLUMN_REP2 = "REP2";
public static final int NUM_COLUMN_REP2 = 5;
public static final String COLUMN_REP3= "REP3";
public static final int NUM_COLUMN_REP3 = 6;
public static final String COLUMN_REP4= "REP4";
public static final int NUM_COLUMN_REP4 = 7;
public static final String COLUMN_REP5= "REP5";
public static final int NUM_COLUMN_REP5 = 8;
private SQLiteDatabase bdd;
private AppreciationOpenHelper maBaseSQLite;
public SurveyAdapter(Context context){
//On créer la BDD et sa table
maBaseSQLite = new AppreciationOpenHelper(context, null);
}
public void open(){
//on ouvre la BDD en écriture
bdd = maBaseSQLite.getWritableDatabase();
}
public void close(){
//on ferme l'accès à la BDD
bdd.close();
}
public SQLiteDatabase getBDD(){
return bdd;
}
public long insertAppreciation(Appreciation app){
//Création d'un ContentValues (fonctionne comme une HashMap)
ContentValues values = new ContentValues();
//on lui ajoute une valeur associé à une clé (qui est le nom de la colonne dans laquelle on veut mettre la valeur)
values.put(COLUMN_ZONE, app.getZone());
values.put(COLUMN_LATITUDE, app.getLatitude());
values.put(COLUMN_LONGITUDE, app.getLongitude());
values.put(COLUMN_REP1, app.getRep1());
values.put(COLUMN_REP2, app.getRep2());
values.put(COLUMN_REP3, app.getRep3());
values.put(COLUMN_REP4, app.getRep4());
values.put(COLUMN_REP5, app.getRep5());
//on insère l'objet dans la BDD via le ContentValues
return bdd.insert(APPRECIATION_TABLE_NAME, null, values);
}
}
这是ApprecationOpenHelper类的代码：
package com.stage.sondage;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
public class AppreciationOpenHelper extends SQLiteOpenHelper {
//version de la base de données
private static final int DATABASE_VERSION = 1;
//le chemin de la base de donnée
private static String DB_PATH = "/data/data/com.stage.sondage/databases/";
//nom de la base
private static final String SURVEY_BASE_NAME="survey.db";
//nom de la table
public static final String APPRECIATION_TABLE_NAME = "Appreciation";
// Description des colonnes
public static final String COLUMN_IDAPPRECIATION = "IDAPPRECIATIONL";
public static final String COLUMN_ZONE = "ZONE";
public static final String COLUMN_LATITUDE = "LATITUDE";
public static final String COLUMN_LONGITUDE = "LONGITUDE";
public static final String COLUMN_REP1 = "REP1";
public static final String COLUMN_REP2 = "REP2";
public static final String COLUMN_REP3= "REP3";
public static final String COLUMN_REP4= "REP4";
public static final String COLUMN_REP5= "REP5";
// Requête SQL pour la création da la base
private static final String REQUETE_CREATION_BDD = "CREATE TABLE "+ APPRECIATION_TABLE_NAME + " (" + COLUMN_IDAPPRECIATION
+ " INTEGER PRIMARY KEY AUTOINCREMENT, " + COLUMN_ZONE
+ " TEXT NOT NULL, " +COLUMN_LATITUDE
+ " DOUBLE NOT NULL, " +COLUMN_LONGITUDE
+ " DOUBLE NOT NULL, " + COLUMN_REP1 + " TEXT NOT NULL, "
+ COLUMN_REP2 + " TEXT NOT NULL,"+COLUMN_REP3 + " TEXT NOT NULL,"
+COLUMN_REP4+"TEXT NOT NULL,"+COLUMN_REP5 +" TEXT NOT NULL);";
public AppreciationOpenHelper(Context context, CursorFactory factory) {
super(context, SURVEY_BASE_NAME, factory, DATABASE_VERSION);
// TODO Auto-generated constructor stub
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
db.execSQL(REQUETE_CREATION_BDD);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
if (newVersion > DATABASE_VERSION) {
db.execSQL("DROP TABLE " + APPRECIATION_TABLE_NAME + ";");
onCreate(db);
}
}
}
这是课程欣赏： package com.stage.sondage;
public class Appreciation {
private int idappreciation;
private String zone;
private double latitude;
private double longitude;
private String rep1;
private String rep2;
private String rep3;
private String rep4;
private String rep5;
public Appreciation(String zone, double latitude, double longitude, String rep1, String rep2, String rep3,String rep4,String rep5){
this.zone=zone;
this.latitude=latitude;
this.longitude=longitude;
this.rep1=rep1;
this.rep2=rep2;
this.rep3=rep3;
this.rep4=rep4;
this.rep5=rep5;
}
public Appreciation() {
// TODO Auto-generated constructor stub
}
public int getIdappreciation() {
return idappreciation;
}
public void setIdappreciation(int idappreciation) {
this.idappreciation = idappreciation;
}
public String getZone() {
return zone;
}
public void setZone(String zone) {
this.zone = zone;
}
public String getRep1() {
return rep1;
}
public void setRep1(String rep1) {
this.rep1 = rep1;
}
public String getRep2() {
return rep2;
}
public void setRep2(String rep2) {
this.rep2 = rep2;
}
public String getRep3() {
return rep3;
}
public void setRep3(String rep3) {
this.rep3 = rep3;
}
public String getRep4() {
return rep4;
}
public void setRep4(String rep4) {
this.rep4 = rep4;
}
public String getRep5() {
return rep5;
}
public void setRep5(String rep5) {
this.rep5 = rep5;
}
public double getLatitude() {
return latitude;
}
public void setLatitude(double latitude) {
this.latitude = latitude;
}
public double getLongitude() {
return longitude;
}
public void setLongitude(double longitude) {
this.longitude = longitude;
}
}
和finnaly这里是我在午餐时得到的logcat错误
07-30 06:33:14.220: E/AndroidRuntime(656): Uncaught handler: thread main exiting due to uncaught exception
07-30 06:33:14.300: E/AndroidRuntime(656): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.stage.sondage/com.stage.sondage.Questionnaire}: java.lang.NullPointerException
07-30 06:33:14.300: E/AndroidRuntime(656): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2496)
07-30 06:33:14.300: E/AndroidRuntime(656): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2512)
07-30 06:33:14.300: E/AndroidRuntime(656): at android.app.ActivityThread.access$2200(ActivityThread.java:119)
07-30 06:33:14.300: E/AndroidRuntime(656): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1863)
07-30 06:33:14.300: E/AndroidRuntime(656): at android.os.Handler.dispatchMessage(Handler.java:99)
07-30 06:33:14.300: E/AndroidRuntime(656): at android.os.Looper.loop(Looper.java:123)
07-30 06:33:14.300: E/AndroidRuntime(656): at android.app.ActivityThread.main(ActivityThread.java:4363)
07-30 06:33:14.300: E/AndroidRuntime(656): at java.lang.reflect.Method.invokeNative(Native Method)
07-30 06:33:14.300: E/AndroidRuntime(656): at java.lang.reflect.Method.invoke(Method.java:521)
07-30 06:33:14.300: E/AndroidRuntime(656): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
07-30 06:33:14.300: E/AndroidRuntime(656): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
07-30 06:33:14.300: E/AndroidRuntime(656): at dalvik.system.NativeStart.main(Native Method)
07-30 06:33:14.300: E/AndroidRuntime(656): Caused by: java.lang.NullPointerException
07-30 06:33:14.300: E/AndroidRuntime(656): at com.stage.sondage.Questionnaire.onCreate(Questionnaire.java:54)
07-30 06:33:14.300: E/AndroidRuntime(656): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
07-30 06:33:14.300: E/AndroidRuntime(656): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2459)
07-30 06:33:14.300: E/AndroidRuntime(656): ... 11 more
谢谢你的帮助
答案 0 :(得分：0)
错误在(com.stage.sondage.Questionnaire.onCreate(Questionnaire.java:54))，你能说明这是哪一行吗？
另外一件事，在以下部分mRadioGroup应该改变吗？ mRadioGroup1，mRadioGroup2，..等：
RadioButton b1 = (RadioButton)findViewById(mRadioGroup1.getCheckedRadioButtonId());
appreciation.setRep1((String) b1.getText());
RadioButton b2 = (RadioButton)findViewById(mRadioGroup1.getCheckedRadioButtonId());
appreciation.setRep1((String) b2.getText());
RadioButton b3 = (RadioButton)findViewById(mRadioGroup1.getCheckedRadioButtonId());
appreciation.setRep1((String) b3.getText());
RadioButton b4 = (RadioButton)findViewById(mRadioGroup1.getCheckedRadioButtonId());
appreciation.setRep1((String) b4.getText());
RadioButton b5 = (RadioButton)findViewById(mRadioGroup1.getCheckedRadioButtonId());
appreciation.setRep1((String) b5.getText());
答案 1 :(得分：0)
after seeing your log there is null pointer exception in below class
**public class Questionnaire extends Activity** ..at line nuber 53 or 54
you may to see that line your class and debugg and see which object value
coming as null and fix it