回按时Android隐藏键盘并关闭底部片断

Question

我遇到了隐藏bottomsheetfragment 和一键后退键盘的问题。当前的实现要求用户单击返回两次以关闭键盘和底页。

我实现了setOnKeyListener，但第一次后退点击隐藏键盘，第二次点击触发后退事件

Link to video

对话框样式

 <style name="BottomSheetDialog" parent="Theme.Design.Light.BottomSheetDialog">
        <item name="android:windowIsFloating">false</item>
        <item name="android:statusBarColor">@android:color/transparent</item>
        <item name="android:windowSoftInputMode">adjustResize</item>
    </style>

class CommentInputFragment : BottomSheetDialogFragment() {

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
     setStyle(DialogFragment.STYLE_NORMAL, R.style.BottomSheetDialog);


}

override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
                          savedInstanceState: Bundle?): View? {
    // Inflate the layout for this fragment
    var view= inflater.inflate(R.layout.fragment_comment_input, container, false)
    return view;
}

override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
    var dialog= super.onCreateDialog(savedInstanceState)

    return dialog

}

override fun onResume() {
    super.onResume()

    dialog?.setOnKeyListener(object: DialogInterface.OnKeyListener
    {
        override fun onKey(p0: DialogInterface?, keyCode: Int, p2: KeyEvent?): Boolean {
            if ((keyCode ==  android.view.KeyEvent.KEYCODE_BACK))
            {
                // To dismiss the fragment when the back-button is pressed.
                dismiss();
                return true;
            }
            // Otherwise, do nothing else
            else return false;
        }
    })
}

override fun onActivityCreated(savedInstanceState: Bundle?) {
    super.onActivityCreated(savedInstanceState)
    et_add_comment.requestFocus();
}


}

Answer 1

隐藏键盘并关闭对话框。

 override fun onKey(p0: DialogInterface?, keyCode: Int, event: KeyEvent?): Boolean {
        if ((keyCode ==  android.view.KeyEvent.KEYCODE_BACK &&  event.getAction()== KeyEvent.ACTION_DOWN))
        {
            // To dismiss the fragment when the back-button is pressed.
            val imm = getSystemService(Context.INPUT_METHOD_SERVICE) as? 
           InputMethodManager
           imm?.hideSoftInputFromWindow(view.windowToken, 0)
            dismiss();
            
            return true;
        }

Answer 2

问题：

如果您注意到返回箭头指向底部（在最近的设备中）而不是左侧，则在这种情况下，对话框不会拦截返回，因为它是由软键盘触发的。所以不会触发dialog?.setOnKeyListener的回调。

所以，你需要通过一些键盘监听器来拦截按键事件；好吧，对于here 和there 等许多帖子来说，这是一个挑战，每个解决方案都可以在特定情况下工作。

解决方案

当调用dispatchKeyEventPreIme() 时，我们将向BottomSheetFragment 布局(R.layout.fragment_comment_input) 的根ViewGroup 注册一个侦听器。这会为附加到此布局的关键事件调用。

创建监听器：

interface OnBackPressListener {
    fun onBackPressed(event: KeyEvent)
}

所以，因为根是FrameLayout，然后自定义它：

class DispatchKeyFrameLayout @JvmOverloads constructor(
    context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0
) : FrameLayout(context, attrs, defStyleAttr) {

    private var listener: OnBackPressListener? = null

    fun setOnBackPressListener (listener: OnBackPressListener) {
        this.listener = listener
    }

    override fun dispatchKeyEventPreIme(event: KeyEvent): Boolean {
        // Trigger the listener callback
        listener?.onBackPressed(event)
        return super.dispatchKeyEventPreIme(event)
    }
}

并将其用作R.layout.fragment_comment_input中的根布局：

<com.example.kotlintest.DispatchKeyFrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/root_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

<!--Other views-->

</com.example.kotlintest.DispatchKeyFrameLayout>

然后在BottomSheetFragment onResume() 中设置监听器以关闭对话框。

override fun onResume() {
    super.onResume()

    layout.setOnBackPressListener(object : OnBackPressListener{
        override fun onBackPressed(event: KeyEvent) {
            if (event.keyCode == android.view.KeyEvent.KEYCODE_BACK)
                dismiss()
        }
    })
}

现在您可以安全地删除dialog?.setOnKeyListener

预览：

Answer 3

我通过使用自定义 EditText 解决了这个问题

public class CustomEditText extends EditText {

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

@Override
public boolean onKeyPreIme(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_BACK) {
        // User has pressed Back key. So hide the keyboard
        InputMethodManager mgr = (InputMethodManager)

                getContext().getSystemService(Context.INPUT_METHOD_SERVICE);
        mgr.hideSoftInputFromWindow(this.getWindowToken(), 0);
    }
    return false;
}
}

Answer 4

override fun onBackPressed() {
    super.onBackPressed()
    val imm = getSystemService(Context.INPUT_METHOD_SERVICE) as? 
       InputMethodManager
    imm?.hideSoftInputFromWindow(view.windowToken, 0)
    dismiss();
 }