将SQLite数据库中的数据显示在Android的ListView中
虽然这个问题在这里已经问了很多次,但我找不到适合我的代码的正确答案。我意识到这可能是小事,但我似乎无法找到问题,因为我只是真的很陌生。将SQLite数据库中的数据显示在Android的ListView中
这里是我的代码getClientNames在DatabaseHelper类:
public Cursor getSitesByClientname(String id) {
String[] args={id};
Cursor myCursor = db.rawQuery("SELECT client_sitename FROM " + CLIENT_SITES_TABLE + " WHERE client_id=?", args);
String results = "";
/*int count = myCursor.getCount();
String[] results = new String[count + 1];
int i = 0;*/
if (myCursor != null) {
if(myCursor.getCount() > 0)
{
for (myCursor.moveToFirst(); !myCursor.isAfterLast(); myCursor.moveToNext())
{
results = results + myCursor.getString(myCursor.getColumnIndex("client_sitename"));
}
}
}
return results;
}
一个问题是,我返回“字符串”到“光标”,但我不知道是什么最好的解决方法,因为我认为我应该返回一个Cursor。
这里的ClientSites类,我想显示的数据:
public class ClientSites extends Activity {
//public final static String ID_EXTRA="com.example.loginfromlocal._ID";
private DBUserAdapter dbHelper = null;
private Cursor ourCursor = null;
private Adapter adapter=null;
@SuppressWarnings("deprecation")
@SuppressLint("NewApi")
public void onCreate(Bundle savedInstanceState) {
try
{
super.onCreate(savedInstanceState);
setContentView(R.layout.client_sites);
Intent i = getIntent();
String uID = String.valueOf(i.getIntExtra("userID", 0));
ListView myListView = (ListView)findViewById(R.id.myListView);
dbHelper = new DBUserAdapter(this);
//dbHelper.createDatabase();
dbHelper.openDataBase();
ourCursor = dbHelper.getSitesByClientname(uID);
Log.e("ALERT", uID.toString());
startManagingCursor(ourCursor);
Log.e("ERROR", "After start manage cursor: ");
//@SuppressWarnings("deprecation")
//SimpleCursorAdapter adapter = new SimpleCursorAdapter(getBaseContext(), R.id.myListView, null, null, null);
CursorAdapter adapter = new SimpleCursorAdapter(this, R.id.myListView, null, null, null, 0);
adapter = new Adapter(ourCursor);
//Toast.makeText(ClientSites.this, "Booo!!!", Toast.LENGTH_LONG).show();
myListView.setAdapter(adapter);
myListView.setOnItemClickListener(onListClick);
}
catch (Exception e)
{
Log.e("ERROR", "XXERROR IN CODE: " + e.toString());
e.printStackTrace();
}
}
private AdapterView.OnItemClickListener onListClick=new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> parent,
View view, int position,
long id)
{
Intent i=new Intent(ClientSites.this, InspectionPoints.class);
i.putExtra(ID_EXTRA, String.valueOf(id));
startActivity(i);
}
};
class Adapter extends CursorAdapter {
@SuppressWarnings("deprecation")
Adapter(Cursor c) {
super(ClientSites.this, c);
}
//@Override
public void bindView(View row, Context ctxt,
Cursor c) {
Holder holder=(Holder)row.getTag();
holder.populateFrom(c, dbHelper);
}
@Override
public View newView(Context ctxt, Cursor c,
ViewGroup parent) {
LayoutInflater inflater=getLayoutInflater();
View row = inflater.inflate(R.layout.row, parent, false);
Holder holder=new Holder(row);
row.setTag(holder);
return(row);
}
}
static class Holder {
private TextView name=null;
Holder(View row) {
name=(TextView)row.findViewById(R.id.ingredientText);
}
void populateFrom(Cursor c, DBUserAdapter r) {
name.setText(r.getName(c));
}
}
}
这里是我现在正在使用尝试在ListView显示数据的代码。我从原来的尝试中改变了一些,但仍然不确定我做错了什么。
public void onCreate(Bundle savedInstanceState) {
try
{
super.onCreate(savedInstanceState);
//setContentView(R.layout.client_sites);
Intent i = getIntent();
String uID = String.valueOf(i.getIntExtra("userID", 0));
//int uID = i.getIntExtra("userID", 0);
//ListView myListView = (ListView)findViewById(R.id.myListView);
dbHelper = new DBUserAdapter(this);
dbHelper.createDatabase();
dbHelper.openDataBase();
String[] results = dbHelper.getSitesByClientname(uID);
//setListAdapter(new ArrayAdapter<String>(ClientSites.this, R.id.myListView, results));
//adapter = new ArrayAdapter<String>(ClientSites.this, R.id.myListView, results);
setListAdapter(new ArrayAdapter<String>(ClientSites.this, R.layout.client_sites, results));
//ListView myListView = (ListView)findViewById(R.id.myListView);
ListView listView = getListView();
listView.setTextFilterEnabled(true);
//ourCursor = dbHelper.getSitesByClientname(uID);
//Log.e("ALERT", uID.toString());
//startManagingCursor(ourCursor);
//Log.e("ERROR", "After start manage cursor: ");
//@SuppressWarnings("deprecation")
//SimpleCursorAdapter adapter = new SimpleCursorAdapter(getBaseContext(), R.id.myListView, null, null, null); // LOOK AT THIS IN THE MORNING!!!!!!!!!!!
//CursorAdapter adapter = new SimpleCursorAdapter(this, R.id.myListView, null, null, null, 0);
//adapter = new Adapter(ourCursor);
//Toast.makeText(ClientSites.this, "Booo!!!", Toast.LENGTH_LONG).show();
//myListView.setAdapter(adapter);
//myListView.setOnItemClickListener(onListClick);
如果你想返回从dbHelper光标,你可以做这样的事情......
public Cursor getSitesByClientname(String id) {
String[] args={id};
return db.rawQuery("SELECT client_sitename FROM " + CLIENT_SITES_TABLE + " WHERE client_id=?", args);
}
我还需要一些时间来阅读listview tutorial
我创建了一个来自数据库的Listview。这里是我用于我的应用程序的代码
这是数据库处理程序的一部分。它会为我的列表视图返回一个类别列表。如果这是你需要的,它可以返回一个字符串列表。
public List<Category> getAllCategorys() {
ArrayList<Category> categoryList = new ArrayList<Category>();
// Select All Query
String selectQuery = "SELECT * FROM " + TABLE_CATEGORY;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// looping through all rows and adding to list
try{
if (cursor.moveToFirst()) {
do {
Category category = new Category();
category.setID(Integer.parseInt(cursor.getString(0)));
category.setCategory(cursor.getString(1));
// Adding category to list
categoryList.add(category);
} while (cursor.moveToNext());
}
}finally{
cursor.close();
}
db.close();
// return category list
return categoryList;
以下是我如何通过调用数据库来填充ListView。
int size = db.getCategoryCount();
List<Category> categoryList = db.getAllCategorys();
category_data = new String[size-1];
int i=0;
for(Category cn : categoryList)
{
category_data[i] = cn.getCategory(); // get the name of the category and add it to array
i++;
}
listAdapter = new ArrayAdapter<String>(this, R.layout.categoryrow, category_data);
listViw.setAdapter(listAdapter);
编辑:这里是应该为你工作
public List<String> getSitesByClientname(String id) {
String[] args={id};
ArrayList<String> result = new ArrayList<String>();
SQLiteDatabase db = this.getWritableDatabase();
Cursor myCursor = db.rawQuery("SELECT client_sitename FROM " + CLIENT_SITES_TABLE + " WHERE client_id=?", args);
try{
if (myCursor.moveToFirst()){
do{
result.add(myCursor.getString(myCusor.getString(myCursor.getColumnIndex("client_sitename"));
}while(myCursor.moveToNext());
}
}finally{
myCursor.close();
}
db.close();
return result;
}
使用方法如下
List<String> sites_data = dbHelper.getSitesByClientname(uID);
result_data = new String[sites_data.size()];
int i=0;
for(String s : sites_data)
{
result_data[i] = s; // get the name of the category and add it to array
i++;
}
listAdapter = new ArrayAdapter<String>(this, R.layout.client_sites, result_data);
listViw.setAdapter(listAdapter);
谢谢Zabador,感谢您的帮助。我现在用我的值返回'string'数组,但不幸的是我仍然无法在我的ListView中显示任何东西。这里是我正在使用的代码来尝试这样做。 – Confucius 2013-03-13 21:45:12
我已经改变了我的代码来显示数据,这与你在这里的内容一致。我想在这里展示它,但似乎没有能力,所以编辑了我的原始问题并将其添加到了底部。如果任何人可以看看,并提供任何意见,我在做什么错我会很感激。 – Confucius 2013-03-13 23:04:01
您可以显示您为您制作的新代码DBUserAdapter类吗? – Zabador 2013-03-14 15:55:30
你为什么不只是光标返回? – njzk2 2013-03-12 14:17:17
是的,我会给出一个去,只是相当新的,所以不太确定正确的语法。谢谢你的帮助。 – Confucius 2013-03-12 21:04:56