我已经创建了一个表及其字段，但我得到错误，不存在这样的行，如果我将它们注释掉，那么它没有检测到表也显示不存在这样的表。这是代码：
package com.example.ifest;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
public class DBHandler extends SQLiteOpenHelper{
private static final String DB_NAME = "event_db";
private static final int DB_VERSION = 1;
private static final String TABLE_NAME = "_table";
private static final String EVENT_NAME = "_name" ;
private static final String EVENT_ID = "_no" ;
private static final String EVENT_TYPE = "_type" ;
public DBHandler(Context context) {
super(context, DB_NAME, null, DB_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE " + TABLE_NAME + " (" + EVENT_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, "
+ EVENT_NAME + " TEXT NOT NULL, " + EVENT_TYPE + " TEXT NOT NULL);" );
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
onCreate(db);
}
我的其他活动的代码是：
public class ProfileView extends ListActivity{
String e,e1;
static int p = 0;
Spinner spn ;
Button b1,b2;
EditText et;
String str1;
ArrayList<String> list = new ArrayList<String>();
ArrayAdapter<String> adapter;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
list.add("Create");
openDB();
p++;
adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,list);
setListAdapter(adapter);
}
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
super.onListItemClick(l, v, position, id);
if(position == 0){
final Dialog build = new Dialog(ProfileView.this);
build.setTitle("String Name and Details");
build.setContentView(R.layout.activity_dialog);
build.show();
spn = (Spinner)build.findViewById(R.id.spinner1_Dialog);
et = (EditText) build.findViewById(R.id.editText1_Dialog);
b2 = (Button) build.findViewById(R.id.button1_Dialog);
b2.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
build.dismiss();
list.add(et.getText().toString());
addDB(et.getText().toString(),spn.getLastVisiblePosition());
adapter.notifyDataSetChanged();
setListAdapter(adapter);
}
});
}
}
protected void addDB(String name,int id) {
DBHandler handle = new DBHandler(this);
SQLiteDatabase db = handle.getWritableDatabase();
ContentValues cv = new ContentValues();
cv.put("_name",name);
if(id == 0)
cv.put("type","WIFI");
else if(id == 1)
cv.put("type","BLUETOOTH");
else if(id == 2)
cv.put("type","MEDIA");
db.insert("_table", null , cv);
db.close();
}
private void openDB() {
if(p != 0){
DBHandler handle = new DBHandler(this);
SQLiteDatabase db = handle.getReadableDatabase();
Cursor c = db.rawQuery("SELECT * FROM "+ "event_db",null);
c.moveToFirst();
while(c.moveToNext()){
list.add(c.getString(1));
Log.d("cursor", c.getString(1));
}
}
}
@Override
public void onCreateContextMenu(ContextMenu menu, View v,ContextMenuInfo menuInfo) {
super.onCreateContextMenu(menu, v, menuInfo);
MenuInflater inflate = getMenuInflater();
inflate.inflate(R.menu.string_main,menu);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater mi = getMenuInflater();
mi.inflate(R.menu.activity_main, menu);
return true;
}
@Override
public boolean onMenuItemSelected(int featureId, MenuItem item) {
switch(item.getItemId()){
case R.id.item1:
final Dialog build = new Dialog(ProfileView.this);
build.setTitle("String Name and Details");
build.setContentView(R.layout.activity_dialog);
build.show();
spn = (Spinner)build.findViewById(R.id.spinner1_Dialog);
et = (EditText) build.findViewById(R.id.editText1_Dialog);
b2 = (Button) build.findViewById(R.id.button1_Dialog);
b2.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
build.dismiss();
list.add(et.getText().toString());
addDB(et.getText().toString(),spn.getLastVisiblePosition());
adapter.notifyDataSetChanged();
setListAdapter(adapter);
}
});
break;
case R.id.item2:
break;
case R.id.item3:
Intent i = new Intent("com.example.ifest.ABOUTUS");
startActivity(i);
break;
case R.id.item4:
finish();
break;
}
return true;
}
}