如何显示来自 ArrayList<GetterSetter> 的特定数据反对ListView? [英] How to display particular data from ArrayList<GetterSetter> object to ListView?
本文介绍了如何显示来自 ArrayList<GetterSetter> 的特定数据反对ListView?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在尝试从 .sqlite 获取数据并将其显示到 ListView 中！
I am trying to fetch data from .sqlite and display it into the ListView !
为此实现了一个 GetterSetter 类，用于通过此方法获取和设置 ArrayList 中的数据 &我成功地将从数据库获得的值打印到控制台:
For that implemented a GetterSetter class for getting and setting the data in the ArrayList by this method & i was successful in printing the values got from database to console :
public ArrayList<GS> getData()
{
try{
Cursor c1 = sdb.rawQuery("SELECT DISTINCT * FROM Articles", null);
gs = new ArrayList<GS>();
while (c1.moveToNext())
{
GS q1 = new GS();
q1.setId(c1.getString(0));
q1.setA_id(c1.getString(1));
q1.setA_name(c1.getString(2));
q1.setAS_name(c1.getString(3)); //--I want this type of list to be in ListView--
q1.setDesc_art(c1.getString(4));
Log.v("id",q1.AS_name+"");
gs.add(q1);
}
}
catch (Exception e) {
e.printStackTrace();
}
return gs;
}
我通过以下方式调用此方法:
I call this method by :
ArrayList<GS> q = db.getData();
那么应该实现什么代码，以在 ListView 中显示它?
So what code should be implemented, to display it in ListView ?
*更新 *:activity_main.xml
*UPDATE * : activity_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<ListView
android:id="@+id/listView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true" >
</ListView>
</RelativeLayout>
customlayout.xml
customlayout.xml
<?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" >
<TextView
android:id="@+id/textView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="TextView" />
</LinearLayout>
DBAdapter.java
DBAdapter.java
public class DBAdapter extends SQLiteOpenHelper
{
CustomAdapter adapter;
static String name = "law.sqlite";
static String path = "";
static ArrayList<GS> gs;
static SQLiteDatabase sdb;
@Override
public void onCreate(SQLiteDatabase db)
{
// TODO Auto-generated method stub
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
{
// TODO Auto-generated method stub
}
private DBAdapter(Context v)
{
super(v, name, null, 1);
path = "/data/data/" + v.getApplicationContext().getPackageName() + "/databases";
}
public boolean checkDatabase()
{
SQLiteDatabase db = null;
try
{
db = SQLiteDatabase.openDatabase(path + "/" + name, null, SQLiteDatabase.OPEN_READONLY);
} catch (Exception e)
{
e.printStackTrace();
}
if (db == null)
{
return false;
}
else
{
db.close();
return true;
}
}
public static synchronized DBAdapter getDBAdapter(Context v)
{
return (new DBAdapter(v));
}
public void createDatabase(Context v)
{
this.getReadableDatabase();
try
{
InputStream myInput = v.getAssets().open(name);
// Path to the just created empty db
String outFileName = path +"/"+ name;
// Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
// transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer)) > 0)
{
myOutput.write(buffer, 0, length);
}
// Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
/*
InputStream is = v.getAssets().open("quiz.sqlite");
// System.out.println(is.available());
System.out.println(new File(path + "/" + name).getAbsolutePath());
FileOutputStream fos = new FileOutputStream(path + "/" + name);
int num = 0;
while ((num = is.read()) > 0) {
fos.write((byte) num);
}
fos.close();
is.close();*/
} catch (IOException e)
{
System.out.println(e);
}
}
public void openDatabase()
{
try
{
sdb = SQLiteDatabase.openDatabase(path + "/" + name, null,
SQLiteDatabase.OPEN_READWRITE);
} catch (Exception e)
{
System.out.println(e);
}
}
public ArrayList<GS> getData()
{
try{
Cursor c1 = sdb.rawQuery("SELECT DISTINCT * FROM Articles", null);
gs = new ArrayList<GS>();
while (c1.moveToNext())
{
GS q1 = new GS();
q1.setId(c1.getString(0));
q1.setA_id(c1.getString(1));
q1.setA_name(c1.getString(2));
q1.setAS_name(c1.getString(3));
q1.setDesc_art(c1.getString(4));
Log.v("id",q1.AS_name+"");
gs.add(q1);
}
}
catch (Exception e) {
e.printStackTrace();
}
return gs;
}
}
MainActivity.java
MainActivity.java
public class MainActivity extends Activity {
ArrayList<GS> q = new ArrayList<GS>();
CustomAdapter adapter;
ListView lv;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Get ListView object from xml
lv = (ListView) findViewById(R.id.listView1);
DBAdapter db = DBAdapter.getDBAdapter(getApplicationContext());
if (!db.checkDatabase())
{
db.createDatabase(getApplicationContext());
}
db.openDatabase();
q = db.getData();
for(int i=0;i<q.size();i++)
{
Log.i("outside",""+q.get(i).getAS_name());
}
lv = (ListView) findViewById(R.id.listView1);
lv.setAdapter(new CustomAdapter(MainActivity.this,q));
lv.setAdapter(adapter);
}
class CustomAdapter extends ArrayAdapter<GS>
{
ArrayList<GS> list;
LayoutInflater mInfalter;
public CustomAdapter(Context context, ArrayList<GS> list)
{
super(context,R.layout.customlayout,list);
this.list= list;
mInfalter = LayoutInflater.from(context);
for(int i=0;i<q.size();i++)
{
Log.i("................",""+list.get(i).getAS_name());
}
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
Log.i("..........","Hello in getView");
if(convertView==null)
{
convertView = mInfalter.inflate(R.layout.customlayout,parent,false);
holder = new ViewHolder();
holder.tv1 = (TextView)convertView.findViewById(R.id.textView1);
convertView.setTag(holder);
}else{
holder = (ViewHolder)convertView.getTag();
}
holder.tv1.setText(list.get(position).getAS_name());
return convertView;
}
}
static class ViewHolder
{
TextView tv1;
}
推荐答案
你有
String[] values = new String[q.size()];
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, android.R.id.text1, values);
但是您在哪里将项目填充到值array.我在您的代码中没有看到这一点.
But where do you populate items to values array. I don't see that in your code.
您可以将自定义 ListView 与自定义适配器一起使用
You can use Custom ListView with a Custom Adapter
ArrayList<GS> q = db.getData();
ListView lv = (ListView) findViewById(R.id.listView);
lv.setAdapter(new CustomAdapter(MainActivity.this,q));
自定义适配器
class CustomAdapter extends ArrayAdapter<GS>
{
ArrayList<GS> list;
LayoutInfalter mInfalter;
public CustomAdapter(Context context, ArrayList<GS> list)
{
super(context,R.layout.customlayout,list);
this.list= list
mInfalter = LayoutInfalter.from(context);
}
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if(convertView==null)
{
convertView = mInflater.inflate(R.layout.customlayout,parent,false);
holder = new ViewHolder();
holder.tv1 = (TextView)convertView.findViewById(R.id.textView1);
convertView.setTag(holder);
}else{
holder = (ViewHolder)convertVire.getTag();
}
holder.tv1.setText(list.get(postion).getAS_name());
return convertVIew;
}
static class ViewHolder
{
TextView tv1;
}
}
在 customlayout.xml 中有一个 ID 为 textview1 的 TextView.
Have a TextView with id textview1 in customlayout.xml.
或
在这种情况下使用 SimpleCursorAdapter 是合适的.
Using SimpleCursorAdapter would be appropriate in this case.
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