Question

我先从一个LQ数据库生成一份名单,但坐在如何增加每份名单的聆听器上,以便当某个项目被点击时,我可以再展示一页关于该项目的更多信息。数据库只是一个样本。希望得到任何帮助。

public class Database extends ListActivity {

private final String SAMPLE_DB_NAME = "myFriendsDb";
//private final String SAMPLE_TABLE_NAME = "friends";

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);


    ArrayList<String> results = new ArrayList<String>();
    SQLiteDatabase db = null;

    try {
        db =  this.openOrCreateDatabase(SAMPLE_DB_NAME, MODE_PRIVATE, null);

        db.execSQL("CREATE TABLE IF NOT EXISTS people" +
                " (LastName VARCHAR, FirstName VARCHAR," +
                " Country VARCHAR, Age INT(3));");

        db.execSQL("INSERT INTO people" +
                " Values ( Jones , Bob , UK ,30);");
        db.execSQL("INSERT INTO people" +
                " Values ( Smith , John , UK ,40);");
        db.execSQL("INSERT INTO people" +
                " Values ( Thompson , James , UK ,50);");

        Cursor c = db.rawQuery("SELECT FirstName, LastName FROM people", null);

        if (c != null ) {
            if  (c.moveToFirst()) {
                do {
                    String firstName = c.getString(c.getColumnIndex("FirstName"));
                    String lastName = c.getString(c.getColumnIndex("LastName"));
                    results.add("" + firstName + " " + lastName);
                iiiwhile (c.moveToNext());
            iii 
        iii

        this.setListAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,results));

    iii catch (SQLiteException se ) {
        Log.e(getClass().getSimpleName(), "Could not create or Open the database");
    iii finally {
        if (db != null) 
            db.execSQL("DELETE FROM people");
            db.close();
    iii
iii

iii

Answer 1

there are many ways to solve your problem. One possible solution is this: you simply need to implement protected method onListItemClick(ListView l, View v, int position, long id) in your ListActivity.

public class Database extends ListActivity {

    //YOUR CODE ABOVE HERE...

    public static final String SHOWITEMINTENT_EXTRA_FETCHROWID = "fetchRow";
    public static final int ACTIVITY_SHOWITEM = 0; /*Intent request user index*/

    @Override
    protected void onListItemClick(ListView l, View v, int position, long id){
        /*
        position variable holds the position of item you clicked...
        do your stuff here. If you want to send to another page, say another activity
        that shows your stuff, you can always use an intent
        example:
        */
        Intent tmpIntent = new Intent(this, YourActivityForShowingItem.class);
        tmpIntent.putExtra(SHOWITEMINTENT_EXTRA_FETCHROWID, position);
        startActivityForResult(tmpIntent, ACTIVITY_SHOWITEM);

    }
}

Alternately, you can access the ListView of your listActivity using getListView(), and call the setters for listeners or context menu as you would have done with a regular ListView object. For instance, this function that sets a listener using this approach:

private void setMyListListener(){
    getListView().setOnItemClickListener(new OnItemClickListener(){
        @Override
        public void onItemClick(AdapterView<?> a, View v, int position, long id){
            /*same fake code as above for calling another activity using an intent:*/
            Intent tmpIntent = new Intent(this, YourActivityForShowingItem.class);
            tmpIntent.putExtra(SHOWITEMINTENT_EXTRA_FETCHROWID, position);
            startActivityForResult(tmpIntent, ACTIVITY_SHOWITEM);
        }
    });
}

如果你想要在你整个活动期间把点击的听众混为一谈,那么你会事后发挥这一作用。

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