这个对我有用，你只需要传递里面的元素。

InputMethodManager imm=(InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
                imm.hideSoftInputFromWindow(AutocompleteviewDoctorState.getWindowToken(), 0);

 fun hideKeyboard(appCompatActivity: AppCompatActivity) {
        val view = appCompatActivity.currentFocus
        val imm = appCompatActivity.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
        imm.hideSoftInputFromWindow(view.windowToken, 0)
    }

在Kotlin中，只需使用这两种方法来显示和隐藏键盘。

fun showKeyboard() =
    (context.getSystemService(AppCompatActivity.INPUT_METHOD_SERVICE) as? InputMethodManager)!!
        .toggleSoftInput(InputMethodManager.SHOW_FORCED, 0)

fun hideKeyboard(view: View) =
    (context.getSystemService(AppCompatActivity.INPUT_METHOD_SERVICE) as? InputMethodManager)!!
        .hideSoftInputFromWindow(view.windowToken, 0)

这里的视图是您当前的视图，

只需在活动中使用此优化代码：

if (this.getCurrentFocus() != null) {
    InputMethodManager inputManager = (InputMethodManager) this.getSystemService(Context.INPUT_METHOD_SERVICE);
    inputManager.hideSoftInputFromWindow(this.getCurrentFocus().getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);
}

这是我的工作。这是在Kotlin隐藏键盘。

private fun hideKeyboard() {
        val inputManager = activity?.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
        val focusedView = activity?.currentFocus
        if (focusedView != null) {
            inputManager.hideSoftInputFromWindow(focusedView.windowToken,
                    InputMethodManager.HIDE_NOT_ALWAYS)
        }
    }

there are two ways to do so...

method 1:in manifest file

define the line **android:windowSoftInputMode="adjustPan|stateAlwaysHidden"** of code in your manifest.xml file as below...

<activity
            android:name="packagename.youactivityname"
            android:screenOrientation="portrait"
            android:windowSoftInputMode="adjustPan|stateAlwaysHidden" />

Method 2 : in Activity or Java class

 if(getCurrentFocus()!=null) {
            InputMethodManager inputMethodManager = (InputMethodManager) getSystemService(INPUT_METHOD_SERVICE)`enter code here`;
            inputMethodManager.hideSoftInputFromWindow(getCurrentFocus().getWindowToken(), 0);
        }

它会work....@ASK