学到关于Sqlite方面的应用,一开始借用了书本上的范例程序自己稍微改了一下,可是一进入显示数据库记录的Activity立刻就报错,但奇怪的是书本上的源程序却能正常运行?!对照着书本源代码修改了很多次,最后受不了索性改得完全一模一样(除了个别名词外)还是显示意外关闭的窗口。网上也没有类似的案例,好心的大哥帮小弟看看吧
我的页面代码:
package lzy.test;import android.app.AlertDialog;
import android.app.ListActivity;
import android.content.DialogInterface;
import android.database.Cursor;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;public class ScoreList extends ListActivity{
@Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
this.setTitle("查看得分记录");
final Score s=new Score(this);
Cursor c=s.query();
String[] from={"_id","name","score","level"};
int[] to={R.id.text01,R.id.text02,R.id.text03,R.id.text04};
SimpleCursorAdapter adapter=new SimpleCursorAdapter(this,R.layout.scorelist,c,from,to);
ListView listview=getListView();
listview.setAdapter(adapter);
final AlertDialog.Builder builder=new AlertDialog.Builder(this);
listview.setOnItemClickListener(new OnItemClickListener(){
public void onItemClick(AdapterView<?> arg0,View arg1,int arg2,long arg3){
final long temp=arg3;
builder.setMessage("真的要删除记录吗?").setPositiveButton("是",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
s.del((int)temp);
Cursor c=s.query();
String[] from={"_id","name","score","level"};
int[] to={R.id.text01,R.id.text02,R.id.text03,R.id.text04};
SimpleCursorAdapter adapter=new SimpleCursorAdapter(getApplicationContext(),R.layout.scorelist,c,from,to);
ListView listview=getListView();
listview.setAdapter(adapter);
}
}).setNegativeButton("否",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
}
});
AlertDialog ad=builder.create();
ad.show();
}
});
s.close();
}
}
书上的源代码:
package com.amaker.test;import android.app.AlertDialog;
import android.app.ListActivity;
import android.content.DialogInterface;
import android.database.Cursor;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.widget.AdapterView.OnItemClickListener;public class QueryActivity extends ListActivity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.setTitle("浏览收藏信息");
final DBHelper helpter = new DBHelper(this);
Cursor c = helpter.query(); String[] from = { "_id", "name", "url", "desc" };
int[] to = { R.id.text0, R.id.text1, R.id.text2, R.id.text3 }; SimpleCursorAdapter adapter = new SimpleCursorAdapter(this,
R.layout.row, c, from, to);
ListView listView = getListView();
listView.setAdapter(adapter);
final AlertDialog.Builder builder = new AlertDialog.Builder(this); listView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
final long temp = arg3;
builder.setMessage("真的要删除该记录吗?").setPositiveButton("是",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int which) {
helpter.del((int)temp);
Cursor c = helpter.query();
String[] from = { "_id", "name", "url", "desc" };
int[] to = { R.id.text0, R.id.text1, R.id.text2, R.id.text3 }; SimpleCursorAdapter adapter = new SimpleCursorAdapter(getApplicationContext(),
R.layout.row, c, from, to);
ListView listView = getListView();
listView.setAdapter(adapter);
}
}).setNegativeButton("否",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int which) {
}
});
AlertDialog ad = builder.create();
ad.show();
}
});
helpter.close();
}
}
我的页面代码:
package lzy.test;import android.app.AlertDialog;
import android.app.ListActivity;
import android.content.DialogInterface;
import android.database.Cursor;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;public class ScoreList extends ListActivity{
@Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
this.setTitle("查看得分记录");
final Score s=new Score(this);
Cursor c=s.query();
String[] from={"_id","name","score","level"};
int[] to={R.id.text01,R.id.text02,R.id.text03,R.id.text04};
SimpleCursorAdapter adapter=new SimpleCursorAdapter(this,R.layout.scorelist,c,from,to);
ListView listview=getListView();
listview.setAdapter(adapter);
final AlertDialog.Builder builder=new AlertDialog.Builder(this);
listview.setOnItemClickListener(new OnItemClickListener(){
public void onItemClick(AdapterView<?> arg0,View arg1,int arg2,long arg3){
final long temp=arg3;
builder.setMessage("真的要删除记录吗?").setPositiveButton("是",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
s.del((int)temp);
Cursor c=s.query();
String[] from={"_id","name","score","level"};
int[] to={R.id.text01,R.id.text02,R.id.text03,R.id.text04};
SimpleCursorAdapter adapter=new SimpleCursorAdapter(getApplicationContext(),R.layout.scorelist,c,from,to);
ListView listview=getListView();
listview.setAdapter(adapter);
}
}).setNegativeButton("否",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
}
});
AlertDialog ad=builder.create();
ad.show();
}
});
s.close();
}
}
书上的源代码:
package com.amaker.test;import android.app.AlertDialog;
import android.app.ListActivity;
import android.content.DialogInterface;
import android.database.Cursor;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.widget.AdapterView.OnItemClickListener;public class QueryActivity extends ListActivity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.setTitle("浏览收藏信息");
final DBHelper helpter = new DBHelper(this);
Cursor c = helpter.query(); String[] from = { "_id", "name", "url", "desc" };
int[] to = { R.id.text0, R.id.text1, R.id.text2, R.id.text3 }; SimpleCursorAdapter adapter = new SimpleCursorAdapter(this,
R.layout.row, c, from, to);
ListView listView = getListView();
listView.setAdapter(adapter);
final AlertDialog.Builder builder = new AlertDialog.Builder(this); listView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
final long temp = arg3;
builder.setMessage("真的要删除该记录吗?").setPositiveButton("是",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int which) {
helpter.del((int)temp);
Cursor c = helpter.query();
String[] from = { "_id", "name", "url", "desc" };
int[] to = { R.id.text0, R.id.text1, R.id.text2, R.id.text3 }; SimpleCursorAdapter adapter = new SimpleCursorAdapter(getApplicationContext(),
R.layout.row, c, from, to);
ListView listView = getListView();
listView.setAdapter(adapter);
}
}).setNegativeButton("否",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int which) {
}
});
AlertDialog ad = builder.create();
ad.show();
}
});
helpter.close();
}
}
package lzy.test;import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;public class Score extends SQLiteOpenHelper{
private static final String DB_NAME="abc.db";
private static final String TBL_NAME="PlayerScore";
private static final String CREATE_TBL="create table"+
"PlayerScore(_id integer primary key autoincrement,name text,score text,level text)";
private SQLiteDatabase db;
Score(Context c){
super(c,DB_NAME,null,2);
}
@Override
public void onCreate(SQLiteDatabase db){
this.db=db;
db.execSQL(CREATE_TBL);
}
public void insert(ContentValues values){
SQLiteDatabase db=getWritableDatabase();
db.insert(TBL_NAME, null, values);
db.close();
}
public Cursor query(){
SQLiteDatabase db=getWritableDatabase();
Cursor c=db.query(TBL_NAME, null, null, null, null, null, null);
return c;
}
public void del(int id){
if(db==null)
db=getWritableDatabase();
db.delete(TBL_NAME, "_id=?", new String[]{String.valueOf(id)});
}
public void close(){
if(db!=null)
db.close();
}
public void onUpgrade(SQLiteDatabase db,int oldVersion,int newVersion){
}
}
书上的数据库源代码:
package com.amaker.test;import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;public class DBHelper extends SQLiteOpenHelper {
private static final String DB_NAME = "coll.db";
private static final String TBL_NAME = "CollTbl";
private static final String CREATE_TBL = " create table "
+ " CollTbl(_id integer primary key autoincrement,name text,url text, desc text) ";
private SQLiteDatabase db; DBHelper(Context c) {
super(c, DB_NAME, null, 2);
} @Override
public void onCreate(SQLiteDatabase db) {
this.db = db;
db.execSQL(CREATE_TBL);
} public void insert(ContentValues values) {
SQLiteDatabase db = getWritableDatabase();
db.insert(TBL_NAME, null, values);
db.close();
} public Cursor query() {
SQLiteDatabase db = getWritableDatabase();
Cursor c = db.query(TBL_NAME, null, null, null, null, null, null);
return c;
} public void del(int id) {
if (db == null)
db = getWritableDatabase();
db.delete(TBL_NAME, "_id=?", new String[] { String.valueOf(id) });
} public void close() {
if (db != null)
db.close();
} @Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { }
}
只把error部分关键地方贴出来就可以了、