Question

我的视图中有一个EditText小部件。当用户选择EditText小部件时，我会显示一些指令并显示软键盘。

我使用OnEditorActionListener来检测用户何时完成文本输入并关闭键盘，隐藏指令并执行某些操作。

我的问题是当用户按BACK键取消键盘时。操作系统取消键盘，但我的指令（我需要隐藏）仍然可见。

我已经尝试重写OnKeyDown，但是当使用BACK按钮关闭键盘时，似乎没有调用它。

我已尝试在EditText小部件上设置OnKeyListener，但似乎也没有调用。

如何检测软键盘何时被解除？

Answer 1

我知道这样做的方法。对EditText进行子类化并实现：

@Override
public boolean onKeyPreIme(int keyCode, KeyEvent event) {
  if (event.getKeyCode() == KeyEvent.KEYCODE_BACK) {
    // Do your thing.
    return true;  // So it is not propagated.
  }
  return super.dispatchKeyEvent(event);
}

以下是有关如何使用自定义视图的链接（用于子类EditText时）： http://developer.android.com/guide/topics/ui/custom-components.html

Answer 2

杰伊，你的解决方案很好！谢谢:)）

public class EditTextBackEvent extends EditText {

    private EditTextImeBackListener mOnImeBack;

    public EditTextBackEvent(Context context) {
        super(context);
    }

    public EditTextBackEvent(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public EditTextBackEvent(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    @Override
    public boolean onKeyPreIme(int keyCode, KeyEvent event) {
        if (event.getKeyCode() == KeyEvent.KEYCODE_BACK && 
            event.getAction() == KeyEvent.ACTION_UP) {
            if (mOnImeBack != null) 
                mOnImeBack.onImeBack(this, this.getText().toString());
        }
        return super.dispatchKeyEvent(event);
    }

    public void setOnEditTextImeBackListener(EditTextImeBackListener listener) {
        mOnImeBack = listener;
    }

}

public interface EditTextImeBackListener {
    public abstract void onImeBack(EditTextBackEvent ctrl, String text);
}

Answer 3

我通过调用super.onKeyPreIme（）对Jay的解决方案稍作改动：

_e = new EditText(inflater.getContext()) {
@Override
public boolean onKeyPreIme(int keyCode, KeyEvent event) {
    if (event.getKeyCode() == KeyEvent.KEYCODE_BACK){
            cancelTextInput();
        }
        return super.onKeyPreIme(keyCode, event);
    }
};

精彩的解决方案，Jay，+ 1！

Answer 4

这是我的自定义EditText，用于检测键盘是否显示

/**
 * Created by TheFinestArtist on 9/24/15.
 */
public class KeyboardEditText extends EditText {

    public KeyboardEditText(Context context) {
        super(context);
    }

    public KeyboardEditText(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public KeyboardEditText(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @Override
    protected void onFocusChanged(boolean focused, int direction, Rect previouslyFocusedRect) {
        super.onFocusChanged(focused, direction, previouslyFocusedRect);
        if (listener != null)
            listener.onStateChanged(this, true);
    }

    @Override
    public boolean onKeyPreIme(int keyCode, @NonNull KeyEvent event) {
        if (event.getKeyCode() == KeyEvent.KEYCODE_BACK
                && event.getAction() == KeyEvent.ACTION_UP) {
            if (listener != null)
                listener.onStateChanged(this, false);
        }
        return super.onKeyPreIme(keyCode, event);
    }

    /**
     * Keyboard Listener
     */
    KeyboardListener listener;

    public void setOnKeyboardListener(KeyboardListener listener) {
        this.listener = listener;
    }

    public interface KeyboardListener {
        void onStateChanged(KeyboardEditText keyboardEditText, boolean showing);
    }
}

Answer 5

只需创建一个扩展Edittext并在代码中使用该edittext的类，您应该只在自定义edittext中覆盖以下方法：

@Override
 public boolean onKeyPreIme(int keyCode, KeyEvent event) {
 if (keyCode == KeyEvent.KEYCODE_BACK) {

    //Here it catch all back keys
    //Now you can do what you want.

} else if (keyCode == KeyEvent.KEYCODE_MENU) {
    // Eat the event
    return true;
}
return false;}

Answer 6

这是关键监听器的解决方案。我不知道为什么会这样，但如果你纯粹在自定义的EditText上覆盖onKeyPreIme，OnKeyListener就可以工作。

SomeClass.java

customEditText.setOnKeyListener((v, keyCode, event) -> {
            if(event.getAction() == KeyEvent.ACTION_DOWN) {
                switch (keyCode) {
                    case KeyEvent.KEYCODE_BACK:
                        getPresenter().onBackPressed();
                        break;
                }
            }
            return false;
        });

CustomEditText.java

@Override
    public boolean onKeyPreIme(int keyCode, KeyEvent event) {
        return super.dispatchKeyEvent(event);
    }

Answer 7

现在是2019年...
所以我用Kotlin创建了一个更简洁的解决方案

1。创建扩展功能：

fun Activity.addKeyboardToggleListener(onKeyboardToggleAction: (shown: Boolean) -> Unit): KeyboardToggleListener? {
    val root = findViewById<View>(android.R.id.content)
    val listener = KeyboardToggleListener(root, onKeyboardToggleAction)
    return root?.viewTreeObserver?.run {
        addOnGlobalLayoutListener(listener)
        listener
    }
}

2。切换侦听器在哪里：

class KeyboardToggleListener(
        private val root: View?,
        private val onKeyboardToggleAction: (shown: Boolean) -> Unit
) : ViewTreeObserver.OnGlobalLayoutListener {
    override fun onGlobalLayout() {
        root?.run {
            val heightDiff = rootView.height - height
            val keyboardShown = heightDiff > dpToPx(200f)
            onKeyboardToggleAction.invoke(keyboardShown)
        }
    }
}

fun View.dpToPx(dp: Float) = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp, resources.displayMetrics).roundToInt()

3. 在以下任何活动中使用它：

addKeyboardToggleListener {shown ->
          // hurray! Now you know when the keyboard is shown and hidden!!
      }

Answer 8

使用@ olivier_sdg的答案，但转换为Kotlin：

class KeyboardEditText : EditText {

    private var mOnImeBack: EditTextImeBackListener? = null

    constructor(context: Context) : super(context)
    constructor(context: Context, attrs: AttributeSet?) : super(context, attrs)
    constructor(context: Context, attrs: AttributeSet?, defStyleAttr: Int) : super(context, attrs, defStyleAttr)

    override fun onKeyPreIme(keyCode: Int, event: KeyEvent): Boolean {
        if (event.keyCode == KeyEvent.KEYCODE_BACK && event.action == KeyEvent.ACTION_UP) {
            if (mOnImeBack != null)
                mOnImeBack!!.onImeBack(this, this.text.toString())
        }
        return super.dispatchKeyEvent(event)
    }

    fun setOnEditTextImeBackListener(listener: EditTextImeBackListener) {
        mOnImeBack = listener
    }

}

interface EditTextImeBackListener {
    fun onImeBack(ctrl: KeyboardEditText, text: String)
}

Answer 9

对于那些希望在Xamarin中做同样事情的人，我已经翻译了一些顶级答案，因为它有点不同。我创建了一个要点here，但总结一下，您创建了一个自定义的EditText并覆盖OnKeyPreIme，如下所示：

public class CustomEditText : EditText
{
    public event EventHandler BackPressed;

    // ...

    public override bool OnKeyPreIme([GeneratedEnum] Keycode keyCode, KeyEvent e)
    {
        if (e.KeyCode == Keycode.Back && e.Action == KeyEventActions.Up)
        {
            BackPressed?.Invoke(this, new EventArgs());
        }

        return base.OnKeyPreIme(keyCode, e);
    }
}

...然后在视图中......

editText = FindViewById<CustomEditText>(Resource.Id.MyEditText);
editText.BackPressed += (s, e) => 
{
    // <insert code here>
};

Answer 10

hideSoftInputFromWindow在键盘关闭时返回true，使用它的值检测android中的键盘关闭

InputMethodManager imm = (InputMethodManager) getContext().getSystemService(Context.INPUT_METHOD_SERVICE);

        if (imm.hideSoftInputFromWindow(findFocus().getWindowToken(),
                InputMethodManager.HIDE_NOT_ALWAYS)) {
            //keyboard is closed now do what you need here
        }

检测用户何时解除软键盘

10 个答案: