我使用此代码以编程方式显示键盘。

binding!!.etAssignToName.postDelayed( {
                mActivity.runOnUiThread {
                    showKeyboard(binding!!.etAssignToName,mContext)
                }
            },300)

fun showKeyboard(editText: EditText, context: Context) {
editText.requestFocus()
val imm: InputMethodManager =
    context.getSystemService(Activity.INPUT_METHOD_SERVICE) as InputMethodManager
imm.showSoftInput(editText, 0)}

fun View.hideSoftKeyboard(context: Context) {
val imm = context.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
imm.hideSoftInputFromWindow(this.windowToken, 0)}

我最终找到了一个解决方案，并为它创建了一个Kotlin类

object KeyboardUtils {

    fun showKeyboard(editText: EditText) {
        editText.requestFocus()
        val imm = editText.context.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
        imm.showSoftInput(editText, 0)
    }

    fun hideKeyboard(editText: EditText) {
        val imm = editText.context.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
        imm.hideSoftInputFromWindow(editText.windowToken, 0)
    }

}

我推荐使用一个LifecycleObserver，它是Android Jetpack中使用生命周期感知组件处理生命周期的一部分。

当片段/活动出现时，我想打开和关闭键盘。首先，为EditText定义两个扩展函数。你可以把它们放在项目的任何地方:

fun EditText.showKeyboard() {
    requestFocus()
    val imm = context.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
    imm.showSoftInput(this, InputMethodManager.SHOW_IMPLICIT)
}

fun EditText.hideKeyboard() {
    val imm = context.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
    imm.hideSoftInputFromWindow(this.windowToken, 0)
}

然后定义一个LifecycleObserver，当Activity/Fragment到达onResume()或onPause时打开和关闭键盘:

class EditTextKeyboardLifecycleObserver(private val editText: WeakReference<EditText>) :
    LifecycleObserver {

    @OnLifecycleEvent(Lifecycle.Event.ON_RESUME)
    fun openKeyboard() {
        editText.get()?.postDelayed({ editText.get()?.showKeyboard() }, 100)
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_PAUSE)
    fun closeKeyboard() {
        editText.get()?.hideKeyboard()
    }
}

然后将下面的行添加到您的任何片段/活动中，您可以在任何时候重用LifecycleObserver。例如，对于片段:

override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

    // inflate the Fragment layout

    lifecycle.addObserver(EditTextKeyboardLifecycleObserver(WeakReference(myEditText)))

    // do other stuff and return the view

}

我只用了一行代码

firstInputField.setNextFocusDownId(R.id.id_of_next_targeted_text_field);

第一个方法:

    etPassword.post(() -> {
        etPassword.requestFocus();
        InputMethodManager manager = (InputMethodManager) getContext().getSystemService(Context.INPUT_METHOD_SERVICE);
        manager.showSoftInput(etPassword, InputMethodManager.SHOW_IMPLICIT);
    });

第二种方式:

在清单:

    <activity
        android:name=".activities.LoginActivity"
        android:screenOrientation="portrait"
        android:windowSoftInputMode="stateVisible"/>

在代码:

etPassword.requestFocus();

我尝试了大卫·梅里曼(David Merriman)的最上面的答案，它也不适合我。但我发现建议运行这段代码延迟在这里，它的工作就像一个魅力。

val editText = view.findViewById<View>(R.id.settings_input_text)

editText.postDelayed({
    editText.requestFocus()

    val imm = context.getSystemService(INPUT_METHOD_SERVICE) as? InputMethodManager
    imm?.showSoftInput(editText, InputMethodManager.SHOW_IMPLICIT)
}, 100)