Question

所以我正计划创建一个简单的“无数据库”待办事项应用程序

我已经能够显示项目并将其添加到列表中。现在，我试图通过传递被单击项的索引来删除。问题是我不知道如何传递参数。任何帮助将不胜感激！

这是我的代码

public class MainActivity extends AppCompatActivity {
    List<String> notesList;
    Toolbar toolbar;
    ListView listNotes;
    ArrayAdapter<String> mAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        toolbar.setTitleTextColor(Color.WHITE);
        notesList = new ArrayList<String>();
       // notesList.add("1");
        listNotes = findViewById(R.id.list_notes);
        delete = findViewById(R.id.btn_delete);
        loadNotesList();
    }

    private void loadNotesList() {
        if(mAdapter == null){
            mAdapter = new ArrayAdapter<String>(this,R.layout.note_item,R.id.note_title, notesList);
            listNotes.setAdapter(mAdapter);
        }
        else {
            mAdapter.clear();
            mAdapter.addAll(notesList);
            mAdapter.notifyDataSetChanged();
        }
    }



    private void displayToast() {
//        notesList.add("test");
        Log.d("list", notesList.toString());
        Toast.makeText(getApplicationContext(), notesList.toString(),
                Toast.LENGTH_LONG).show();
    }

    private void deleteNote(View view){
        View parent = (View)view.getParent();
        TextView noteTitleTextView = (TextView)findViewById(R.id.note_title);
        String noteTitle = String.valueOf(noteTitleTextView.getText());
        Toast.makeText(getApplicationContext(), noteTitleTextView.toString(),
                Toast.LENGTH_LONG).show();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        notesList = new ArrayList<String>();
        //notesList.add("tset vissew");
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_actions, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_add) {
            displayToast();

            final EditText noteEditText = new EditText(this);
            AlertDialog dialog = new AlertDialog.Builder(this)
                    .setTitle("Add a new note")
                    .setMessage("What's on your mind?")
                    .setView(noteEditText)
                    .setPositiveButton("Add", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            String note = String.valueOf(noteEditText.getText());
                            notesList.add(note);
                            loadNotesList();
                            displayToast();
                        }
                    })
                    .setNegativeButton("Cancel", null)
                    .create();
            dialog.show();
            //loadNotesList();
            //displayToast();

        }

        return super.onOptionsItemSelected(item);
    }
}

我的列表项布局

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="16dp">
    <TextView
        android:id="@+id/note_title"
        android:text="Example"
        android:textSize="20sp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentLeft="true"
        android:gravity="center"/>
    <Button
        android:id="@+id/btn_delete"
        android:text="Delete"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentEnd="true"
        android:layout_alignParentRight="true" />
</RelativeLayout>

代码看起来非常丑陋，对此感到抱歉。

Answer 1

为您的ListView添加OnItemClickListener

listNotes.setOnItemClickListener(new AdapterView.OnItemClickListener() {
       @Override
       public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
       //here position is index of your list's item
    }
 });

当从列表视图中单击按钮时，如何传递项目的索引？

1 个答案: