我不是 android 编程方面的专家，这是一个课程作业。每次我尝试使用模拟器插入数据时，logcat 都会告诉我该表不存在。我想我可能没有正确调用我的 onCreate 方法，但我不知道。想知道是否有人可以向我指出，这是我的代码：
package com.mknowles.locationapp;
import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;
public class Entries {
public static final String KEY_ID = "_id";
public static final String KEY_TITLE = "title";
public static final String KEY_LOCATION = "location";
public static final String KEY_DATE = "entryDate";
public static final String KEY_TIME = "entryTime";
public static final String KEY_DESCRIPTION = "description";
private static final String DB_NAME = "LocationEntries_db";
private static final String DB_TABLE = "entries_table";
private static final int DB_VERSION = 1;
private DbHelper dbhelper;
private final Context appContext;
private SQLiteDatabase entriesDb;
private static class DbHelper extends SQLiteOpenHelper {
public DbHelper(Context context) {
super(context, DB_NAME, null, DB_VERSION);
// TODO Auto-generated constructor stub
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
db.execSQL(
"CREATE TABLE " + DB_TABLE + " ("
+ KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, "
+ KEY_TITLE + " TEXT NOT NULL, "
+ KEY_LOCATION + "TEXT, "
+ KEY_DATE + " TEXT NOT NULL, "
+ KEY_TIME + " TEXT, "
+ KEY_DESCRIPTION + " TEXT);"
);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
db.execSQL("DROP TABLE IF EXISTS " + DB_TABLE);
onCreate(db);
}
}
public Entries(Context context){
appContext = context;
}
public Entries open(){
dbhelper = new DbHelper(appContext);
entriesDb = dbhelper.getWritableDatabase();
return this;
}
public void close(){
dbhelper.close();
}
public long createEntry(String title, String location, String date, String time, String description) {
// TODO Auto-generated method stub
ContentValues cv = new ContentValues();
cv.put(KEY_TITLE, title);
cv.put(KEY_LOCATION, location);
cv.put(KEY_DATE, date);
cv.put(KEY_TIME, time);
cv.put(KEY_DESCRIPTION, description);
return entriesDb.insert(DB_TABLE, null, cv);
}
}
package com.mknowles.locationapp;
import android.os.Bundle;
import android.app.Activity;
import android.database.sqlite.SQLiteDatabase;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class MakeEntryActivity extends Activity implements OnClickListener {
Button sqlSave;
EditText mTitle, mLocation, mDate, mTime, mDescription;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_make_entry);
mTitle = (EditText) findViewById(R.id.etTitle);
mLocation = (EditText) findViewById(R.id.etLocation);
mDate = (EditText) findViewById(R.id.etDate);
mTime = (EditText) findViewById(R.id.etTime);
mDescription = (EditText) findViewById(R.id.etDescription);
sqlSave = (Button) findViewById(R.id.bSave);
sqlSave.setOnClickListener(this);
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
switch(v.getId()){
case R.id.bSave:
String title = mTitle.getText().toString();
String location = mLocation.getText().toString();
String date = mDate.getText().toString();
String time = mTime.getText().toString();
String description = mDescription.getText().toString();
Entries entry = new Entries(MakeEntryActivity.this);
entry.open();
entry.createEntry(title, location, date, time, description);
entry.close();
Toast t = Toast.makeText(this, "Saving", Toast.LENGTH_SHORT);
t.show();
break;
}
}
}