Android 键盘回车响应问题点

在阅读Android4.0高级编程时，发现对EditText添加键盘响应的监听接口中"回车"的问题；

（1）如果使用 SDK版本< 16版时，点击回车可以正常提交；

（2）如果使用 SDK版本>=16 时，点击回车不会提交，而是换行；

<uses-sdk
        android:minSdkVersion="4"
        android:targetSdkVersion="17" />

代码如下：

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.testlistadapter"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="4"
        android:targetSdkVersion="17" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.testlistadapter.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

code:

package com.example.testlistadapter;

import java.util.ArrayList;

import android.app.Activity;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.KeyEvent;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListView;

public class MainActivity extends Activity {

    private EditText edt_input;
    private ListView lv_show;

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

        edt_input = (EditText) findViewById(R.id.edt_input);
        lv_show = (ListView) findViewById(R.id.lv_show);

        final ArrayList<String> arrayList = new ArrayList<String>();
        final ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(
                this, android.R.layout.simple_list_item_1, arrayList);

        edt_input.setOnKeyListener(new View.OnKeyListener() {

            @Override
            public boolean onKey(View v, int keyCode, KeyEvent event) {
                // TODO Auto-generated method stub
                if (event.getAction() == KeyEvent.ACTION_DOWN) {
                    if (keyCode == KeyEvent.KEYCODE_DPAD_CENTER
                            || keyCode == KeyEvent.KEYCODE_ENTER) {

                        String str = edt_input.getText().toString();
                        if (TextUtils.isEmpty(str))
                            return false;
                        else {
                            arrayList.add(0, str);
                            arrayAdapter.notifyDataSetChanged();
                            edt_input.setText("");
                        }

                        return true;
                    }
                }

                return false;
            }
        });

        lv_show.setAdapter(arrayAdapter);
    }
}