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)
    }

}

这对我很有效， 多亏了ungalcrys

显示键盘:

editText = (EditText)findViewById(R.id.myTextViewId);
editText.requestFocus();
InputMethodManager imm = (InputMethodManager)getSystemService(this.INPUT_METHOD_SERVICE);
imm.toggleSoftInput(InputMethodManager.SHOW_FORCED,InputMethodManager.HIDE_IMPLICIT_ONLY);

隐藏键盘:

InputMethodManager imm = (InputMethodManager) getSystemService(this.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(editText.getWindowToken(), 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

}

试试这个:

EditText editText = (EditText) findViewById(R.id.myTextViewId);
editText.requestFocus();
InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
imm.showSoftInput(editText, InputMethodManager.SHOW_IMPLICIT);

requestFocus (http://developer.android.com/reference/android/view/View.html)

我尝试了很多方法，但它不起作用，不确定是因为我使用共享过渡从片段到包含编辑文本的活动。

顺便说一句，我的编辑文本也包装在线性布局。

我添加了一个轻微的延迟来请求焦点，下面的代码对我来说是有效的: (芬兰湾的科特林)

 et_search.postDelayed({
     editText.requestFocus()

     showKeyboard()
 },400) //only 400 is working fine, even 300 / 350, the cursor is not showing

showKeyboard ()

 val imm = getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
 imm.toggleSoftInput(InputMethodManager.SHOW_FORCED, 0)

final EditText tb = new EditText(this);
tb.requestFocus();
tb.postDelayed(new Runnable() {
    @Override
    public void run() {
        InputMethodManager inputMethodManager = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
        inputMethodManager.showSoftInput(tb, InputMethodManager.SHOW_IMPLICIT);
    }
}, 1000);