我有一个例子，我的EditText也可以位于AlertDialog中，所以键盘应该在关闭时关闭。以下代码似乎在任何地方都有效：

public static void hideKeyboard( Activity activity ) {
    InputMethodManager imm = (InputMethodManager)activity.getSystemService( Context.INPUT_METHOD_SERVICE );
    View f = activity.getCurrentFocus();
    if( null != f && null != f.getWindowToken() && EditText.class.isAssignableFrom( f.getClass() ) )
        imm.hideSoftInputFromWindow( f.getWindowToken(), 0 );
    else 
        activity.getWindow().setSoftInputMode( WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN );
}

要在应用程序启动时显示键盘：

        getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_PAN | WindowManager.LayoutParams.SOFT_INPUT_STATE_VISIBLE);
        view.requestFocus();
        new Handler().postDelayed(new Runnable() {
            public void run() {
                getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_PAN);
            }
        }, 1000);

对于开放式键盘：

InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
imm.showSoftInput(edtView, InputMethodManager.SHOW_IMPLICIT);

对于关闭/隐藏键盘：

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

下面是如何在Mono for Android（AKA MonoDroid）中实现的

InputMethodManager imm = GetSystemService (Context.InputMethodService) as InputMethodManager;
if (imm != null)
    imm.HideSoftInputFromWindow (searchbox.WindowToken , 0);

我几乎尝试了所有这些答案，我遇到了一些随机问题，特别是三星galaxy s5。

我最终的结果是强迫表演和隐藏，而且效果很好：

/**
 * Force show softKeyboard.
 */
public static void forceShow(@NonNull Context context) {
    InputMethodManager imm = (InputMethodManager) context.getSystemService(Context.INPUT_METHOD_SERVICE);
    imm.toggleSoftInput(InputMethodManager.SHOW_FORCED, 0);
}

/**
 * Force hide softKeyboard.
 */
public static void forceHide(@NonNull Activity activity, @NonNull EditText editText) {
    if (activity.getCurrentFocus() == null || !(activity.getCurrentFocus() instanceof EditText)) {
        editText.requestFocus();
    }
    InputMethodManager imm = (InputMethodManager) activity.getSystemService(Context.INPUT_METHOD_SERVICE);
    imm.hideSoftInputFromWindow(editText.getWindowToken(), 0);
    activity.getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
}

/** 
 *
 *   Hide I Said!!!
 *
 */
public static boolean hideSoftKeyboard(@NonNull Activity activity) {
    View currentFocus = activity.getCurrentFocus();
    if (currentFocus == null) {
        currentFocus = activity.getWindow().getDecorView();
        if (currentFocus != null) {
            return getSoftInput(activity).hideSoftInputFromWindow(currentFocus.getWindowToken(), 0, null);
        }
    }
    return false;
}

public static boolean hideSoftKeyboard(@NonNull Context context) {
   if(Activity.class.isAssignableFrom(context.getClass())){
       return hideSoftKeyboard((Activity)context);
   }
   return false;
}

public static InputMethodManager getSoftInput(@NonNull Context context) {
    return (InputMethodManager) context.getSystemService(Activity.INPUT_METHOD_SERVICE);
}