如何从我的数据库中的数据,并把它放在一个ListView是可以点击的? [英] How to get data from my database and put it on a ListView that is clickable?
问题描述
我想学习的SQLite
。我想从数据库中(的TextView
)把信息发送到的ListView
是可点击(我还是不有想法可点击的ListView
)。我能得到如何从我的数据库中的数据,并把它放在一个的ListView
是可以点击的一些帮助?下面是一个教程的网站,我想有一个的ListView
的code:
按钮ViewBack;
@覆盖
保护无效的onCreate(包savedInstanceState){
// TODO自动生成方法存根
super.onCreate(savedInstanceState);
的setContentView(R.layout.sqlview);
ViewBack =(按钮)findViewById(R.id.bVBack);
TextView的电视=(TextView中)findViewById(R.id.tvSQLinfo);
ViewBack.setOnClickListener(本);
HotOrNot信息=新HotOrNot(本);
info.open();
字符串数据= info.geData();
info.close();
tv.setText(数据);
}
@覆盖
公共无效的onClick(视图v){
// TODO自动生成方法存根
完();
}
sqlview.xml
:
<滚动型
机器人:layout_width =FILL_PARENT
机器人:layout_height =match_parent>
<的TextView
机器人:ID =@ + ID / tvSQLinfo
机器人:layout_width =FILL_PARENT
机器人:layout_height =FILL_PARENT
机器人:layout_marginTop =10dp
机器人:文本=得到数据库信息/>
< /滚动型>
起初,我试图把这样的:
的ListView LV =(ListView控件)findViewById(R.id.listMe);
ListAdapter listAD =新ListAdapter(这一点,R.id.listMe,电视);
lv.setAdapter(listAD);
但我得到了不能实例化的数据类型 ListAdapter
的错误,所以我想关于更换 SimpleCursorAdapter
的新ListAdapter(这一点,R.id.listMe,电视)
:
ListAdapter listAD =新SimpleCursorAdapter(这一点,R.id.listMe,电视,NULL,NULL);
但它给了我又是一个错误,认为我改变强制转换为光标
所以,我改变了这一切,直到它并没有给我任何错误。当我试图运行它,它不会工作。这里的 HotOrNotClass
:
公共静态最后弦乐KEY_ROWID =_id;
公共静态最后弦乐KEY_NAME =persons_name;
公共静态最后弦乐KEY_HOTNESS =presons_hotness;
私有静态最后弦乐DATABASE_NAME =HotOrNotdb;
公共静态最后弦乐DATABASE_TABLE =peopleTable;
私有静态最终诠释DATABASE_VERSION = 1;
私人DbHelper ourHelper;
私人最终语境ourContext;
私人SQLiteDatabase ourDatabase;
私有静态类DbHelper扩展SQLiteOpenHelper {
公共DbHelper(上下文的背景下){
超(背景下,DATABASE_NAME,空,DATABASE_VERSION);
// TODO自动生成构造函数存根
}
@覆盖
公共无效的onCreate(SQLiteDatabase DB){
// TODO自动生成方法存根
db.execSQL(CREATE TABLE+ DATABASE_TABLE +(+
KEY_ROWID +INTEGER PRIMARY KEY AUTOINCREMENT,+
KEY_NAME +TEXT NOT NULL,+
KEY_HOTNESS +TEXT NOT NULL);
);
}
@覆盖
公共无效onUpgrade(SQLiteDatabase分贝,INT oldVersion,诠释静态网页){
// TODO自动生成方法存根
db.execSQL(DROP TABLE IF EXISTS+ DATABASE_TABLE);
的onCreate(DB);
}
}
公共HotOrNot(上下文C){
ourContext = C;
}
公共HotOrNot的open()抛出SQLiteException {
ourHelper =新DbHelper(ourContext);
ourDatabase = ourHelper.getWritableDatabase();
回到这一点; }
公共无效的close(){
ourHelper.close();
}
众长createEntry(字符串名称,字符串辣味){
// TODO自动生成方法存根
ContentValues CV =新ContentValues();
cv.put(KEY_NAME,姓名);
cv.put(KEY_HOTNESS,辣味);
返回ourDatabase.insert(DATABASE_TABLE,空,CV);
}
公共字符串geData(){
// TODO自动生成方法存根
的String []列=新的String [] {KEY_ROWID,KEY_NAME,KEY_HOTNESS};
光标C = ourDatabase.query(DATABASE_TABLE,列,NULL,NULL,NULL,NULL,NULL);
字符串结果=;
INT iRow = c.getColumnIndex(KEY_ROWID);
INT INAME = c.getColumnIndex(KEY_NAME);
INT iHotness = c.getColumnIndex(KEY_HOTNESS);
为(c.moveToFirst();!c.isAfterLast(); c.moveToNext()){
结果=结果+ c.getString(iRow)++ c.getString(INAME)++ c.getString(iHotness)+\ N的;
}
返回结果;
}
公共字符串的getName(长L)抛出SQLiteException {
// TODO自动生成方法存根
的String []列=新的String [] {KEY_ROWID,KEY_NAME,KEY_HOTNESS};
光标C = ourDatabase.query(DATABASE_TABLE,列,KEY_ROWID +=+ 1,NULL,NULL,NULL,NULL);
如果(C!= NULL){
c.moveToFirst();
字符串名称= c.getString(1);
返回名称;
}
返回null;
}
公共字符串getHotness(长L)抛出SQLiteException {
// TODO自动生成方法存根
的String []列=新的String [] {KEY_ROWID,KEY_NAME,KEY_HOTNESS};
光标C = ourDatabase.query(DATABASE_TABLE,列,KEY_ROWID +=+ 1,NULL,NULL,NULL,NULL);
如果(C!= NULL){
c.moveToFirst();
串辣味= c.getString(2);
返回的辣味;
}
返回null;
}
您的getData()
方法返回一个大的字符串
所有的结果。我不认为这是你想为你的名单是什么,这样修改getData()方法,因此您可以返回字符串
列表重presenting您的数据库记录
公开的ArrayList<字符串> geData(){
// TODO自动生成方法存根
的String []列=新的String [] {KEY_ROWID,KEY_NAME,KEY_HOTNESS};
光标C = ourDatabase.query(DATABASE_TABLE,列,NULL,NULL,NULL,NULL,NULL);
ArrayList的<字符串>结果=新的ArrayList<字符串>();
INT iRow = c.getColumnIndex(KEY_ROWID);
INT INAME = c.getColumnIndex(KEY_NAME);
INT iHotness = c.getColumnIndex(KEY_HOTNESS);
为(c.moveToFirst();!c.isAfterLast(); c.moveToNext()){
result.add(c.getString(iRow)++ c.getString(INAME)++ c.getString(iHotness));
}
返回结果;
}
为了显示一个列表,你必须把的ListView
元素在活动
布局( sqlview
),所以你可以作出这样的布局:
< XML版本=1.0编码=UTF-8&GT?;
< LinearLayout中的xmlns:机器人=http://schemas.android.com/apk/res/android
机器人:layout_width =match_parent
机器人:layout_height =match_parent
机器人:方向=垂直>
<按钮
机器人:ID =@ + ID / bVBack
机器人:layout_width =WRAP_CONTENT
机器人:layout_height =WRAP_CONTENT
机器人:文本=东西/>
<的ListView
机器人:ID =@ + ID / listMe
机器人:layout_width =FILL_PARENT
机器人:layout_height =WRAP_CONTENT/>
< / LinearLayout中>
然后在你的的onCreate()
方法绑定的ListView
到适配器
:
// ...
ListView的LV =(ListView控件)findViewById(R.id.listMe);
HotOrNot信息=新HotOrNot(本);
info.open();
ArrayList的<字符串>数据= info.geData();
info.close();
lv.setAdapter(新ArrayAdapter<字符串>(这一点,android.R.layout.simple_list_item1,数据));
I'm trying to learn SQLite
. I wanted to put the information from the database(TextView
) to a ListView
that is clickable(I still don't have idea in clickable ListView
). Can I get some help on how to get data from my database and put it on a ListView
that is clickable? Here is the code from a tutorial site that I wanted to have in a ListView
:
Button ViewBack;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.sqlview);
ViewBack=(Button) findViewById(R.id.bVBack);
TextView tv = (TextView) findViewById(R.id.tvSQLinfo);
ViewBack.setOnClickListener(this);
HotOrNot info = new HotOrNot(this);
info.open();
String data = info.geData();
info.close();
tv.setText(data);
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
finish();
}
sqlview.xml
:
<ScrollView
android:layout_width="fill_parent"
android:layout_height="match_parent" >
<TextView
android:id="@+id/tvSQLinfo"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_marginTop="10dp"
android:text="get info from db" />
</ScrollView>
At first I tried putting this:
ListView lv = (ListView) findViewById(R.id.listMe);
ListAdapter listAD = new ListAdapter(this,R.id.listMe, tv);
lv.setAdapter(listAD);
but I get an error that cannot instantiate the data type ListAdapter
, so I tried replacing SimpleCursorAdapter
on the new ListAdapter(this,R.id.listMe,tv)
:
ListAdapter listAD = new SimpleCursorAdapter (this,R.id.listMe,tv, null, null);
but it gives me again an error, it suggest that I change the cast to Cursor
so, I changed all of it until it didn't give me any errors. When I tried to run it, it wouldn't work. Here's the HotOrNotClass
:
public static final String KEY_ROWID= "_id";
public static final String KEY_NAME= "persons_name";
public static final String KEY_HOTNESS= "presons_hotness";
private static final String DATABASE_NAME= "HotOrNotdb";
public static final String DATABASE_TABLE= "peopleTable";
private static final int DATABASE_VERSION= 1;
private DbHelper ourHelper;
private final Context ourContext;
private SQLiteDatabase ourDatabase;
private static class DbHelper extends SQLiteOpenHelper{
public DbHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
// TODO Auto-generated constructor stub
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
db.execSQL("CREATE TABLE " + DATABASE_TABLE + " (" +
KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
KEY_NAME + " TEXT NOT NULL, " +
KEY_HOTNESS + " TEXT NOT NULL);"
);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
db.execSQL("DROP TABLE IF EXISTS " +DATABASE_TABLE);
onCreate(db);
}
}
public HotOrNot(Context c){
ourContext=c;
}
public HotOrNot open() throws SQLiteException{
ourHelper = new DbHelper(ourContext);
ourDatabase =ourHelper.getWritableDatabase();
return this; }
public void close(){
ourHelper.close();
}
public long createEntry(String name, String hotness) {
// TODO Auto-generated method stub
ContentValues cv = new ContentValues();
cv.put(KEY_NAME, name);
cv.put(KEY_HOTNESS, hotness);
return ourDatabase.insert(DATABASE_TABLE, null, cv);
}
public String geData() {
// TODO Auto-generated method stub
String[]columns=new String[]{ KEY_ROWID,KEY_NAME, KEY_HOTNESS};
Cursor c =ourDatabase.query(DATABASE_TABLE, columns, null, null, null, null, null);
String result ="";
int iRow=c.getColumnIndex(KEY_ROWID);
int iName=c.getColumnIndex(KEY_NAME);
int iHotness=c.getColumnIndex(KEY_HOTNESS);
for(c.moveToFirst(); !c.isAfterLast();c.moveToNext()){
result=result + c.getString(iRow)+" "+c.getString(iName)+" "+c.getString(iHotness)+"\n";
}
return result;
}
public String getName(long l) throws SQLiteException{
// TODO Auto-generated method stub
String[]columns=new String[]{ KEY_ROWID,KEY_NAME, KEY_HOTNESS};
Cursor c= ourDatabase.query(DATABASE_TABLE, columns, KEY_ROWID+"="+l, null, null, null, null);
if (c!=null){
c.moveToFirst();
String name=c.getString(1);
return name;
}
return null;
}
public String getHotness(long l)throws SQLiteException {
// TODO Auto-generated method stub
String[]columns=new String[]{ KEY_ROWID,KEY_NAME, KEY_HOTNESS};
Cursor c= ourDatabase.query(DATABASE_TABLE, columns, KEY_ROWID+"="+l, null, null, null, null);
if (c!=null){
c.moveToFirst();
String hotness=c.getString(2);
return hotness;
}
return null;
}
Your getData()
method returns a big String
with all the results. I don't think this is what you want for your list, so modify the getData() method so you can return a list of String
representing your database records:
public ArrayList<String> geData() {
// TODO Auto-generated method stub
String[]columns=new String[]{ KEY_ROWID,KEY_NAME, KEY_HOTNESS};
Cursor c =ourDatabase.query(DATABASE_TABLE, columns, null, null, null, null, null);
ArrayList<String> result = new ArrayList<String>();
int iRow=c.getColumnIndex(KEY_ROWID);
int iName=c.getColumnIndex(KEY_NAME);
int iHotness=c.getColumnIndex(KEY_HOTNESS);
for(c.moveToFirst(); !c.isAfterLast();c.moveToNext()){
result.add(c.getString(iRow)+" "+c.getString(iName)+" "+c.getString(iHotness));
}
return result;
}
In order to show a list you'll have to put a ListView
element in your Activity
layout(sqlview
) so you could make the layout like this:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<Button
android:id="@+id/bVBack"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Something" />
<ListView
android:id="@+id/listMe"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
</LinearLayout>
Then in your onCreate()
method bind the ListView
to an Adapter
:
//...
ListView lv = (ListView) findViewById(R.id.listMe);
HotOrNot info = new HotOrNot(this);
info.open();
ArrayList<String> data = info.geData();
info.close();
lv.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item1, data));
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