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;
                }
            }
        });

Kotlin解决方案的反应进入按使用Lambda表达式:

        editText.setOnKeyListener { _, keyCode, event ->
            if(keyCode == KeyEvent.KEYCODE_ENTER && event.action==KeyEvent.ACTION_DOWN){
            //react to enter press here
            }
            true
        }

不做额外的检查类型的事件将导致这个监听器被调用两次时按一次(一次为ACTION_DOWN，一次为ACTION_UP)

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()
}

我想知道是否有办法 处理用户按Enter键时 输入EditText之类的 onSubmit HTML事件。

是的。

也在想有没有办法 操作虚拟键盘 就像“完成”按钮一样 标记其他东西(例如 “Go”)并执行某个动作 当点击(再次，像onSubmit)。

也没错。

你会想看看android:imeActionId和android:imeOptions属性，加上setOnEditorActionListener()方法，所有的TextView。

要将“Done”按钮的文本更改为自定义字符串，请使用:

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

我使用Kotlin创建了一个函数，它可以处理EditText的所有“完成”动作，包括键盘，并且可以修改它，也可以处理其他按键:

private val DEFAULT_ACTIONS_TO_HANDLE_AS_DONE_FOR_EDIT_TEXT = arrayListOf(EditorInfo.IME_ACTION_SEND, EditorInfo.IME_ACTION_GO, EditorInfo.IME_ACTION_SEARCH, EditorInfo.IME_ACTION_DONE)
private val DEFAULT_KEYS_TO_HANDLE_AS_DONE_FOR_EDIT_TEXT = arrayListOf(KeyEvent.KEYCODE_ENTER, KeyEvent.KEYCODE_NUMPAD_ENTER)

fun EditText.setOnDoneListener(function: () -> Unit, onKeyListener: OnKeyListener? = null, onEditorActionListener: TextView.OnEditorActionListener? = null,
                               actionsToHandle: Collection<Int> = DEFAULT_ACTIONS_TO_HANDLE_AS_DONE_FOR_EDIT_TEXT,
                               keysToHandle: Collection<Int> = DEFAULT_KEYS_TO_HANDLE_AS_DONE_FOR_EDIT_TEXT) {
    setOnEditorActionListener { v, actionId, event ->
        if (onEditorActionListener?.onEditorAction(v, actionId, event) == true)
            return@setOnEditorActionListener true
        if (actionsToHandle.contains(actionId)) {
            function.invoke()
            return@setOnEditorActionListener true
        }
        return@setOnEditorActionListener false
    }
    setOnKeyListener { v, keyCode, event ->
        if (onKeyListener?.onKey(v, keyCode, event) == true)
            return@setOnKeyListener true
        if (event.action == KeyEvent.ACTION_DOWN && keysToHandle.contains(keyCode)) {
            function.invoke()
            return@setOnKeyListener true
        }
        return@setOnKeyListener false
    }
}

那么，示例用法:

        editText.setOnDoneListener({
            //do something
        })

至于改变标签，我认为这取决于键盘应用，它通常只在横屏上改变，就像这里写的那样。总之，这个的用法示例:

        editText.imeOptions = EditorInfo.IME_ACTION_DONE
        editText.setImeActionLabel("ASD", editText.imeOptions)

或者，如果你想用XML:

    <EditText
        android:id="@+id/editText" android:layout_width="wrap_content" android:layout_height="wrap_content"
        android:imeActionLabel="ZZZ" android:imeOptions="actionDone" />

结果(横屏显示):

我通过扩展新的MaterialAlertDialogBuilder创建了一个辅助类

使用

new InputPopupBuilder(context)
        .setInput(R.string.send, 
                R.string.enter_your_message, 
                text -> sendFeedback(text, activity))
        .setTitle(R.string.contact_us)
        .show();

Code

public class InputPopupBuilder extends MaterialAlertDialogBuilder {

    private final Context context;
    private final AppCompatEditText input;

    public InputPopupBuilder(Context context) {
        super(context);
        this.context = context;
        input = new AppCompatEditText(context);
        input.setInputType(InputType.TYPE_CLASS_TEXT);
        setView(input);
    }

    public InputPopupBuilder setInput(int actionLabel, int hint, Callback callback) {
        input.setHint(hint);
        input.setImeActionLabel(context.getString(actionLabel), KeyEvent.KEYCODE_ENTER);
        input.setOnEditorActionListener((TextView.OnEditorActionListener) (v, actionId, event) -> {
            if (actionId == EditorInfo.IME_NULL
                    && event.getAction() == KeyEvent.ACTION_DOWN) {
                Editable text = input.getText();
                if (text != null) {
                    callback.onClick(text.toString());
                    return true;
                }
            }
            return false;
        });

        setPositiveButton(actionLabel, (dialog, which) -> {
            Editable text = input.getText();
            if (text != null) {
                callback.onClick(text.toString());
            }
        });

        return this;
    }

    public InputPopupBuilder setText(String text){
        input.setText(text);
        return this;
    }

    public InputPopupBuilder setInputType(int inputType){
        input.setInputType(inputType);
        return this;
    }

    public interface Callback {
        void onClick(String text);
    }
}

需要

implementation 'com.google.android.material:material:1.3.0-alpha04'