Question

以下示例对我来说无法正常运行。根据代码，当按下“ENTER”键时，它应该在ListView中添加条目。但它只是在EditText字段中输入新行，并没有真正在ListView中添加该条目。运行应用程序时，我没有收到任何错误。这是我的活动和XML文件。

MainActivity.java

package com.example.todo_list;

import java.util.ArrayList;
import android.app.Activity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;
import android.view.View.OnKeyListener;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListView;

public class MainActivity extends Activity {

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

// Inflate your view
setContentView(R.layout.activity_main);

// Get references to UI widgets
ListView myListView = (ListView)findViewById(R.id.myListView);
final EditText myEditText = (EditText)findViewById(R.id.myEditText);

// Create the array list of to do items
final ArrayList<String> todoItems = new ArrayList<String>();
// Create the array adapter to bind the array to the listview
final ArrayAdapter<String> aa;
aa = new ArrayAdapter<String>(this,
                              android.R.layout.simple_list_item_1,
                              todoItems);
// Bind the array adapter to the listview.
myListView.setAdapter(aa);

myEditText.setOnKeyListener(new OnKeyListener() {
    public boolean onKey(View v, int keyCode, KeyEvent event) {
      if (event.getAction() == KeyEvent.ACTION_DOWN)
        if (keyCode == KeyEvent.KEYCODE_ENTER)
        {
          todoItems.add(0, myEditText.getText().toString());
          aa.notifyDataSetChanged();
          myEditText.setText("");
          return true;
        }
      return false;
    }
  });
  }
}

activity_main.xml中

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" xmlns:android="http://schemas.android.com/apk/res/android">
    <EditText
        android:id="@+id/myEditText"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:hint="New To Do Item"
    />

    <ListView
        android:id="@+id/myListView"
        android:layout_width="match_parent"
        android:layout_height="427dp" >
    </ListView>

Answer 1

首先检查按Enter键时是否触发了myEditText.setOnKeyListener。

如果是，则在edittext xml中添加这些属性

ndroid:singleLine="true"
android:lines="1"

希望它能奏效。

待办事项列表示例对我不起作用

1 个答案: