public static void hideSoftKeyboard(Activity activity) {
    InputMethodManager inputMethodManager = (InputMethodManager) activity
            .getSystemService(Activity.INPUT_METHOD_SERVICE);
    inputMethodManager.hideSoftInputFromWindow(activity.getCurrentFocus()
            .getWindowToken(), 0);
}

记下所有这些答案，简单地说，我写了一个常用的方法：

/**
 * hide soft keyboard in a activity
 * @param activity
 */
public static void hideKeyboard (Activity activity){
    activity.getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_HIDDEN);
    if (activity.getCurrentFocus() != null) {
        InputMethodManager inputMethodManager = (InputMethodManager) activity.getSystemService(activity.INPUT_METHOD_SERVICE);
        inputMethodManager.hideSoftInputFromWindow(activity.getCurrentFocus().getWindowToken(), 0);
    }
}

以下是使用Kotlin隐藏软键盘的最简单方法：

//hides soft keyboard anything else is tapped( screen, menu bar, buttons, etc. )
override fun dispatchTouchEvent( ev: MotionEvent? ): Boolean {
    if ( currentFocus != null ) {
        val imm = getSystemService( Context.INPUT_METHOD_SERVICE ) as InputMethodManager
        imm.hideSoftInputFromWindow( currentFocus!!.windowToken, 0 )
    }
    return super.dispatchTouchEvent( ev )
}

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);
}

在AndroidManifest.xml中的<activity..>set android:windowSoftInputMode=“stateAlwaysHidden”

多亏了这个SO答案，我得出了以下结论，在我的情况下，当滚动浏览ViewPager的片段时，它很好地工作。。。

private void hideKeyboard() {   
    // Check if no view has focus:
    View view = this.getCurrentFocus();
    if (view != null) {
        InputMethodManager inputManager = (InputMethodManager) this.getSystemService(Context.INPUT_METHOD_SERVICE);
        inputManager.hideSoftInputFromWindow(view.getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);
    }
}

private void showKeyboard() {   
    // Check if no view has focus:
    View view = this.getCurrentFocus();
    if (view != null) {
        InputMethodManager inputManager = (InputMethodManager) this.getSystemService(Context.INPUT_METHOD_SERVICE);
        inputManager.showSoftInput(view, InputMethodManager.SHOW_IMPLICIT);
    }
}