这应该是有效的：

public class KeyBoard {

    public static void show(Activity activity){
        InputMethodManager imm = (InputMethodManager) activity.getSystemService(Activity.INPUT_METHOD_SERVICE);
        imm.toggleSoftInput(0, InputMethodManager.HIDE_IMPLICIT_ONLY); // show
    }

    public static void hide(Activity activity){
        InputMethodManager imm = (InputMethodManager) activity.getSystemService(Activity.INPUT_METHOD_SERVICE);
        imm.toggleSoftInput(InputMethodManager.HIDE_IMPLICIT_ONLY, 0); // hide
    }

    public static void toggle(Activity activity){
        InputMethodManager imm = (InputMethodManager) activity.getSystemService(Activity.INPUT_METHOD_SERVICE);
        if (imm.isActive()){
            hide(activity); 
        } else {
            show(activity); 
        }
    }
}

KeyBoard.toggle(activity);

我正在使用以下Kotlin Activity扩展：

/**
 * Hides soft keyboard if is open.
 */
fun Activity.hideKeyboard() {
    currentFocus?.windowToken?.let {
        (getSystemService(Context.INPUT_METHOD_SERVICE) as? InputMethodManager?)
                ?.hideSoftInputFromWindow(it, InputMethodManager.HIDE_NOT_ALWAYS)
    }
}

/**
 * Shows soft keyboard and request focus to given view.
 */
fun Activity.showKeyboard(view: View) {
    view.requestFocus()
    currentFocus?.windowToken?.let {
        (getSystemService(Context.INPUT_METHOD_SERVICE) as? InputMethodManager?)
                ?.showSoftInput(view, InputMethodManager.SHOW_IMPLICIT)
    }
}

别忘了：智能手机的系统设置是“输入方法和语言->物理键盘->显示屏幕键盘->开/关”。此设置“干扰”了此处的所有编程解决方案！我必须禁用/启用此设置才能完全隐藏/显示屏幕键盘！因为我是为MC2200设备开发的，所以我使用“EMDK配置文件管理->Ui管理器->虚拟键盘状态->显示/隐藏”

如果您需要在片段中隐藏键盘，则此方法有效。

public static void hideSoftKeyboard(Context context, View view) {
    if (context != null && view != null) {
        InputMethodManager imm = (InputMethodManager) context.getSystemService(Activity.INPUT_METHOD_SERVICE);
        imm.hideSoftInputFromWindow(view.getWindowToken(), 0);
    }
}

对于视图，只需传入

getView() method

我的解决方案：

用活动构造它（视图是可选的），使用处理程序发布它（有一些延迟，例如100ms更好）。直接调用输入管理器有时不起作用。只有在工作时才能获得“活动”。我认为这很正常。

如果您可以在通话时获取根视图组或编辑视图，只需发送它即可获得更好的结果。

public class CloseSoftKeyboardRunnable implements Runnable
{
    Activity activity;
    View view;  // for dialog will occur context getcurrentfocus == null. send a rootview to find currentfocus.

    public CloseSoftKeyboardRunnable(Activity activity, View view)
    {
        this.activity = activity;
        this.view = view;
    }

    public CloseSoftKeyboardRunnable(Activity activity)
    {
        this.activity = activity;
    }
    @Override
    public void run() {
        if (!activity.isFinishing())
        {
            InputMethodManager imm = (InputMethodManager)activity.getSystemService(Context.INPUT_METHOD_SERVICE);

            if (view == null) {
                view = activity.getCurrentFocus();
            }
            else
            {
                try {
                    view = ((ViewGroup)view).getFocusedChild();
                }
                catch ( Exception e) {}
            }

            Window window =  activity.getWindow();
            
            if (window != null)
            {
                if (view == null) {
                    try {
                        view = window.getDecorView();
                        view = ((ViewGroup)view).getFocusedChild();
                    }
                    catch ( Exception e) {}
                }

                if (view == null) {
                    view = window.getDecorView();
                }

                if (view != null) {
                    if (view instanceof EditText)
                    {
                        EditText edittext = ((EditText) view);
                        edittext.setText(edittext.getText().toString()); // reset edit text bug on some keyboards bug
                        edittext.clearFocus();
                    }

                    imm.hideSoftInputFromWindow(view.getWindowToken(), 0);
                }
                window.setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
            }
        }
    }
}

对于Xamarin.Android：

public void HideKeyboard()
{
    var imm = activity.GetSystemService(Context.InputMethodService).JavaCast<InputMethodManager>();
    var view = activity.CurrentFocus ?? new View(activity);
    imm.HideSoftInputFromWindow(view.WindowToken, HideSoftInputFlags.None);
}