作为Chad响应的补充(对我来说几乎完美)，我发现我需要在KeyEvent操作类型上添加一个检查，以防止代码执行两次(一次在key-up事件上执行，一次在key-down事件上执行)。

if (actionId == EditorInfo.IME_NULL && event.getAction() == KeyEvent.ACTION_DOWN)
{
    // your code here
}

有关重复动作事件(按住enter键)的信息，请参见http://developer.android.com/reference/android/view/KeyEvent.html。

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);

检测回车键被按下的最简单的方法是:

mPasswordField.setOnEditorActionListener(new TextView.OnEditorActionListener() {
            @Override
            public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
                if (event!= null) {   // KeyEvent: If triggered by an enter key, this is the event; otherwise, this is null.
                    signIn(mEmailField.getText().toString(), mPasswordField.getText().toString());
                    return true;
                } else {
                    return false;
                }
            }
        });

I had a similar purpose. I wanted to resolve pressing the "Enter" key on the keyboard (which I wanted to customize) in an AutoCompleteTextView which extends TextView. I tried different solutions from above and they seemed to work. BUT I experienced some problems when I switched the input type on my device (Nexus 4 with AOKP ROM) from SwiftKey 3 (where it worked perfectly) to the standard Android keyboard (where instead of handling my code from the listener, a new line was entered after pressing the "Enter" key. It took me a while to handle this problem, but I don't know if it will work under all circumstances no matter which input type you use.

这是我的解决方案:

在xml中设置TextView的输入类型属性为"text":

android:inputType="text"

自定义键盘上“Enter”键的标签:

myTextView.setImeActionLabel("Custom text", KeyEvent.KEYCODE_ENTER);

将OnEditorActionListener设置为TextView:

myTextView.setOnEditorActionListener(new OnEditorActionListener()
{
    @Override
    public boolean onEditorAction(TextView v, int actionId,
        KeyEvent event)
    {
    boolean handled = false;
    if (event.getAction() == KeyEvent.KEYCODE_ENTER)
    {
        // Handle pressing "Enter" key here

        handled = true;
    }
    return handled;
    }
});

我希望这能帮助其他人避免我遇到的问题，因为它们几乎把我逼疯了。

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;
    }
});

这将在用户按下返回键时为您提供一个可调用的函数。

fun EditText.setLineBreakListener(onLineBreak: () -> Unit) {
    val lineBreak = "\n"
    doOnTextChanged { text, _, _, _ ->
        val currentText = text.toString()

        // Check if text contains a line break
        if (currentText.contains(lineBreak)) {

            // Uncommenting the lines below will remove the line break from the string
            // and set the cursor back to the end of the line

            // val cleanedString = currentText.replace(lineBreak, "")
            // setText(cleanedString)
            // setSelection(cleanedString.length)

            onLineBreak()
        }
    }
}

使用

editText.setLineBreakListener {
    doSomething()
}