Question

我已经在网上搜索了高低。尝试了几个技巧和教程，但没有一个真正适合我。

我要做的是使用多个选择列表删除列表中的多个条目。一切正常，并且列表在xml中设置为multiplechoice，但在尝试更新我的自定义列表时，我似乎无法解决此问题。

我正在使用一个resourcecursoradapter，不知道这是不是问题，但我现在不知所措，所以如果有任何机构可以帮助我那将会很棒。

现在我的活动代码。

    package com.ShaHar91.ivlibrary;

    import java.io.IOException;
    import java.io.InputStream;

    import android.app.AlertDialog;
    import android.app.ListActivity;
    import android.content.Context;
    import android.content.DialogInterface;
    import android.content.res.AssetManager;
    import android.database.Cursor;
    import android.database.SQLException;
    import android.graphics.drawable.Drawable;
    import android.os.AsyncTask;
    import android.os.Bundle;
    import android.util.SparseBooleanArray;
    import android.view.LayoutInflater;
    import android.view.Menu;
    import android.view.MenuItem;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.CheckBox;
    import android.widget.ImageView;
    import android.widget.ListView;
    import android.widget.RadioButton;
    import android.widget.ResourceCursorAdapter;
    import android.widget.TextView;
    import android.widget.Toast;

    @SuppressWarnings("deprecation")
    public class DeleteMultiPoke extends ListActivity {
public static final String ROW_ID = "row_id"; // Intent extra key
private long rowID;
MyAdapter mListAdapter;

Menu menu;
MenuItem delete;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_layout);

    DatabaseConnector myDbHelper = new DatabaseConnector(
            DeleteMultiPoke.this);
    try {
        myDbHelper.createDataBase();
    } catch (IOException ioe) {
        throw new Error("Unable to create database");
    }
    try {
        DatabaseConnector.openDataBase();
    } catch (SQLException sqle) {
        throw sqle;
    }

    Cursor myCur = null;

    myCur = myDbHelper.getAllPokes();

    mListAdapter = new MyAdapter(DeleteMultiPoke.this, myCur);
    setListAdapter(mListAdapter);

}

private class MyAdapter extends ResourceCursorAdapter {

    public MyAdapter(Context context, Cursor cur) {
        super(context, R.layout.poke_list_remove_item, cur);

    }

    @Override
    public View newView(Context context, Cursor cur, ViewGroup parent) {
        LayoutInflater li = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        return li.inflate(R.layout.poke_list_remove_item, parent, false);
    }

    @Override
    public void bindView(View view, Context context, Cursor cur) {
        TextView pokeTv = (TextView) view.findViewById(R.id.pokeTv);
        TextView genderTv = (TextView) view.findViewById(R.id.genderTv);

        RadioButton hpRb = (RadioButton) view.findViewById(R.id.hpRb);
        RadioButton attRb = (RadioButton) view.findViewById(R.id.attRb);
        RadioButton defRb = (RadioButton) view.findViewById(R.id.defRb);
        RadioButton spAttRb = (RadioButton) view.findViewById(R.id.spAttRb);
        RadioButton spDefRb = (RadioButton) view.findViewById(R.id.spDefRb);
        RadioButton speedRb = (RadioButton) view.findViewById(R.id.speedRb);
        ImageView pokeSprite = (ImageView) view
                .findViewById(R.id.pokeSpriteIV);

        pokeTv.setText(cur.getString(cur.getColumnIndex("name")));
        genderTv.setText(cur.getString(cur.getColumnIndex("gender")));

        hpRb.setChecked((cur.getInt(cur.getColumnIndex("hp")) == 0 ? false
                : true));
        attRb.setChecked((cur.getInt(cur.getColumnIndex("att")) == 0 ? false
                : true));
        defRb.setChecked((cur.getInt(cur.getColumnIndex("def")) == 0 ? false
                : true));
        spAttRb.setChecked((cur.getInt(cur.getColumnIndex("sp_att")) == 0 ? false
                : true));
        spDefRb.setChecked((cur.getInt(cur.getColumnIndex("sp_def")) == 0 ? false
                : true));
        speedRb.setChecked((cur.getInt(cur.getColumnIndex("speed")) == 0 ? false
                : true));

        AssetManager assetManager = getAssets();

        int imageIndex = cur.getColumnIndex("nat_dex");
        try {
            InputStream ims = assetManager.open("pokes/"
                    + cur.getString(imageIndex) + ".gif");

            Drawable d = Drawable.createFromStream(ims, null);

            pokeSprite.setImageDrawable(d);

        } catch (IOException ex) {
            return;
        }

    }

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.poke_menu_remove, menu);

    delete = menu.findItem(R.id.deletepokes);
    delete.setEnabled(false);
    delete.setVisible(false);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    case R.id.canceldeleting:
        finish();
        return true;
    case R.id.deletepokes:
        // create a new AlertDialog Builder
        AlertDialog.Builder builder = new AlertDialog.Builder(
                DeleteMultiPoke.this);

        builder.setTitle(R.string.confirmTitle); // title bar string
        builder.setMessage(R.string.confirmMessage); // message to display

        // provide an OK button that simply dismisses the dialog
        builder.setPositiveButton(R.string.button_delete,
                new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int button) {
                        final DatabaseConnector databaseConnector = new DatabaseConnector(
                                DeleteMultiPoke.this);

                        ListView listView = (ListView) findViewById(android.R.id.list);
                        SparseBooleanArray checked = listView
                                .getCheckedItemPositions();

                        for (int i = checked.size() - 1; i >= 0; i--) {
                            final int position = checked.keyAt(i);
                            if (checked.valueAt(i)) {
                                AsyncTask<Long, Object, Object> deleteTask = new AsyncTask<Long, Object, Object>() {

                                    @Override
                                    protected Object doInBackground(
                                            Long... params) {
                                        databaseConnector.deletePoke(mListAdapter
                                                .getItemId(position));

                                        return null;
                                    }

                                    @Override
                                    protected void onPostExecute(
                                            Object result) {

                                        finish(); // return to the
                                                    // BookLibrary Activity
                                    }
                                };

                                // delete the AsyncTask to delete book at
                                // rowID
                                deleteTask.execute(new Long[] { rowID });
                            }
                        }

                    } // end method onClick
                });
        builder.setNegativeButton(R.string.button_cancel, null);
        builder.show();

        return true;
    default:

        return super.onOptionsItemSelected(item);
    }

}

@Override
protected void onResume() {
    super.onResume();
    mListAdapter.getCursor().requery();
}

@Override
protected void onStop() {
    super.onStop();
}

@Override
protected void onListItemClick(ListView l, View v, int position, long id) {

    String selected = "";

    int cntChoice = l.getCount();

    SparseBooleanArray sparseBooleanArray = l.getCheckedItemPositions();

    for (int i = 0; i < cntChoice; i++) {

        if (sparseBooleanArray.get(i)) {

            selected += l.getItemAtPosition(i).toString() + "\n";

        }

    }

    Toast.makeText(DeleteMultiPoke.this,

    selected,

    Toast.LENGTH_LONG).show();

    if (l.getCheckedItemCount() == 0) {
        delete.setEnabled(false);
        delete.setVisible(false);
    } else {
        delete.setEnabled(true);
        delete.setVisible(true);

    }

}

提前Ty， Christiano Bolla

Answer 1

您应该在删除任何项目后通过调用列表适配器上的notifyDataSetChanged()来通知列表基础数据源已更改。

回收listview与复选框

1 个答案: