小编Cin*_*ong的帖子

我是Android的新手,并被要求开发Android的应用程序.我正在使用Android 2.2.我遇到的问题是,一旦我点击基本教程中的"添加"按钮,就会出现客户端的名称,但它不会那样工作.单击按钮后,列表视图中未显示该名称.

这里的代码:

public class MainActivity extends Activity implements OnClickListener,       
OnKeyListener  {

    ArrayList<String> appointment;
    ArrayAdapter<String> aa;

    EditText editText1;
    Button addButton;
    ListView listView1;

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

        editText1 = (EditText)findViewById(R.id.editText1);
        addButton = (Button)findViewById(R.id.addButton);
        listView1 = (ListView)findViewById(R.id.listView1);

        addButton.setOnClickListener(this);
        editText1.setOnKeyListener(this);

        appointment = new ArrayList<String>();
        aa = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,  
                appointment);
        listView1.setAdapter(aa);

    }

    private void addItems(String item){

        if (item.length()>0){
            this.appointment.add(item);
            this.aa.notifyDataSetChanged();
            this.editText1.setText("");
        }

    }

    public void onClick(View v) {

        if(v==this.addButton){
            this.addItems(this.editText1.getText().toString()); …