下面是一个简单的静态函数，您可以将它扔到Utils或keyboard类中，当用户敲击硬件或软件键盘上的返回键时，它将执行代码。这是@earlcasper精彩回答的修改版

 /**
 * Return a TextView.OnEditorActionListener that will execute code when an enter is pressed on
 * the keyboard.<br>
 * <code>
 *     myTextView.setOnEditorActionListener(Keyboards.onEnterEditorActionListener(new Runnable()->{
 *         Toast.makeText(context,"Enter Pressed",Toast.LENGTH_SHORT).show();
 *     }));
 * </code>
 * @param doOnEnter A Runnable for what to do when the user hits enter
 * @return the TextView.OnEditorActionListener
 */
public static TextView.OnEditorActionListener onEnterEditorActionListener(final Runnable doOnEnter){
    return (__, actionId, event) -> {
        if (event==null) {
            if (actionId == EditorInfo.IME_ACTION_DONE) {
                // Capture soft enters in a singleLine EditText that is the last EditText.
                doOnEnter.run();
                return true;
            } else if (actionId==EditorInfo.IME_ACTION_NEXT) {
                // Capture soft enters in other singleLine EditTexts
                doOnEnter.run();
                return true;
            } else {
                return false;  // Let system handle all other null KeyEvents
            }
        } else if (actionId==EditorInfo.IME_NULL) {
            // Capture most soft enters in multi-line EditTexts and all hard enters.
            // They supply a zero actionId and a valid KeyEvent rather than
            // a non-zero actionId and a null event like the previous cases.
            if (event.getAction()==KeyEvent.ACTION_DOWN) {
                // We capture the event when key is first pressed.
                return true;
            } else {
                doOnEnter.run();
                return true;   // We consume the event when the key is released.
            }
        } else {
            // We let the system handle it when the listener
            // is triggered by something that wasn't an enter.
            return false;
        }
    };
}

你可以用这种方法

editText.setOnEditorActionListener((v, actionId, event) -> {
       if (actionId == EditorInfo.IME_ACTION_DONE) {
          // Do some things      
          return true;
       }
       return false;
});

你可以在那里看到行动清单。

例如:

IME_ACTION_GO

IME_ACTION_SEARCH

IME_ACTION_SEND

你应该这样做。它也隐藏在Android开发者的样例代码“蓝牙聊天”中。用你自己的变量和方法替换“example”的粗体部分。

首先，把你需要的东西导入到主Activity中，你想让返回按钮做一些特殊的事情:

import android.view.inputmethod.EditorInfo;
import android.widget.TextView;
import android.view.KeyEvent;

现在，创建一个类型为TextView的变量。OnEditorActionListener作为返回键(这里我使用exampleListener);

TextView.OnEditorActionListener exampleListener = new TextView.OnEditorActionListener(){

然后，您需要告诉侦听器当按下返回按钮时该做什么。它需要知道我们谈论的EditText是什么(这里我使用exampleView)，然后它需要知道当按下Enter键时要做什么(这里是example_confirm())。如果这是活动中最后一个或唯一一个EditText，它应该做与提交(或确定，确认，发送，保存等)按钮的onClick方法相同的事情。

public boolean onEditorAction(TextView exampleView, int actionId, KeyEvent event) {
   if (actionId == EditorInfo.IME_NULL  
      && event.getAction() == KeyEvent.ACTION_DOWN) { 
      example_confirm();//match this behavior to your 'Send' (or Confirm) button
   }
   return true;
}

最后，设置监听器(很可能在你的onCreate方法中);

exampleView.setOnEditorActionListener(exampleListener);

在xml中，将imeOptions属性添加到editText中

<EditText
    android:id="@+id/edittext_additem"
    ...
    android:imeOptions="actionDone"
    />

然后，在Java代码中，将OnEditorActionListener添加到相同的EditText中

mAddItemEditText.setOnEditorActionListener(new TextView.OnEditorActionListener() {
        @Override
        public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
            if(actionId == EditorInfo.IME_ACTION_DONE){
                //do stuff
                return true;
            }
            return false;
        }
    });

下面是解释 imeOptions=actionDone将“actionDone”分配给EnterKey。键盘上的EnterKey将从“Enter”变为“Done”。因此，当按下回车键时，它将触发这个动作，因此您将处理它。

如果使用DataBinding，请参见https://stackoverflow.com/a/52902266/2914140和https://stackoverflow.com/a/67933283/2914140。

Bindings.kt:

@BindingAdapter("onEditorEnterAction")
fun EditText.onEditorEnterAction(callback: OnActionListener?) {
    if (callback == null) setOnEditorActionListener(null)
    else setOnEditorActionListener { v, actionId, event ->
        val imeAction = when (actionId) {
            EditorInfo.IME_ACTION_DONE,
            EditorInfo.IME_ACTION_SEND,
            EditorInfo.IME_ACTION_GO -> true
            else -> false
        }

        val keydownEvent = event?.keyCode == KeyEvent.KEYCODE_ENTER 
            && event.action == KeyEvent.ACTION_DOWN

        if (imeAction or keydownEvent) {
            callback.enterPressed()
            return@setOnEditorActionListener true
        }
        return@setOnEditorActionListener false
    }
}

interface OnActionListener {
    fun enterPressed()
}

layout.xml:

<data>
    <variable
        name="viewModel"
        type="YourViewModel" />
</data>    

<EditText
    android:imeOptions="actionDone|actionSend|actionGo"
    android:singleLine="true"
    android:text="@={viewModel.message}"
    app:onEditorEnterAction="@{() -> viewModel.send()}" />

final EditText edittext = (EditText) findViewById(R.id.edittext);
edittext.setOnKeyListener(new OnKeyListener() {
    public boolean onKey(View v, int keyCode, KeyEvent event) {
        // If the event is a key-down event on the "enter" button
        if ((event.getAction() == KeyEvent.ACTION_DOWN) &&
            (keyCode == KeyEvent.KEYCODE_ENTER)) {
          // Perform action on key press
          Toast.makeText(HelloFormStuff.this, edittext.getText(), Toast.LENGTH_SHORT).show();
          return true;
        }
        return false;
    }
});