OnKeyListener()未执行

Question

有人能告诉我为什么OnKey()方法中的代码没有执行吗？请注意，我正在尝试触发我点击android键盘上的“搜索”按钮。

下面是主要代码：

package com.onkeyexample1;

import android.app.Activity;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.view.KeyEvent;
import android.view.View;
import android.view.View.OnKeyListener;
import android.widget.EditText;

public class OnKeyExample1Activity extends Activity {
EditText editText;
OnKeyListener onKeyListener;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    editText = (EditText) findViewById(R.id.editText1);
    editText.setOnKeyListener(onKeyListener);
    editText.addTextChangedListener(inputTextWatcher);

onKeyListener = new OnKeyListener() {
    @Override
    public boolean onKey(View v, int keyCode, KeyEvent event) {
           System.out.println("Clicked");
        return true;
                 }
   };
}

我尝试添加下面的代码块作为建议的修复，但没有帮助：

    private TextWatcher inputTextWatcher = new TextWatcher() {
        public void afterTextChanged(Editable s) { }
        public void beforeTextChanged(CharSequence s, int start, int count, int after)
            { }
        public void onTextChanged(CharSequence s, int start, int before, int count) {
           // Log.d(TAG, s.charAt(count-1) + " character to send");;          
        }
    };
}

下面是我的布局xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello"
    />
<EditText android:imeOptions="actionSearch" android:layout_width="fill_parent" 
   android:id="@+id/editText1" android:layout_height="wrap_content">
    <requestFocus></requestFocus>
</EditText>
</LinearLayout>

任何建议都是非常感谢的！

以下是Ted建议的第一个实现：

public class OnKeyExample1Activity extends Activity {
EditText editText;
OnKeyListener onKeyListener;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    editText = (EditText) findViewById(R.id.editText1);
editText.setOnKeyListener(onKeyListener = new OnKeyListener() {
    @Override
    public boolean onKey(View v, int keyCode, KeyEvent event) {
           System.out.println("Clicked");
        return true;
                 }  
});
}
}

下面是我在评论中提到的双重触发问题的修复方法：

editText.setOnKeyListener(onKeyListener = new OnKeyListener() {
    @Override
    public boolean onKey(View v, int keyCode, KeyEvent event) {
        if (event.getAction() != KeyEvent.ACTION_DOWN) {  
             System.out.println("Argh");
             return false;
         }
        return true;
    } 
});
}

Answer 1

在调用editText.setOnKeyListener(onKeyListener);之前，您需要为onKeyListener赋值。只需将赋值移到方法调用之前，它就应该可以工作了。