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

在调用onTouchListener之后：

findViewById(android.R.id.content).setOnTouchListener(new OnTouchListener() {
    @Override
    public boolean onTouch(View v, MotionEvent event) {
        Utils.hideSoftKeyboard(activity);
        return false;
    }
});

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);
    }
}

我创建了一个布局，部分来自xml，部分来自自定义布局引擎，所有这些都在代码中处理。对我来说，唯一有效的方法是跟踪键盘是否打开，并使用如下键盘切换方法：

public class MyActivity extends Activity
{
    /** This maintains true if the keyboard is open. Otherwise, it is false. */
    private boolean isKeyboardOpen = false;

    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        LayoutInflater inflater;
        inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View contentView = inflater.inflate(context.getResources().getIdentifier("main", "layout", getPackageName()), null);

        setContentView(contentView);
        contentView.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() 
        {
            public void onGlobalLayout() 
            {
                Rect r = new Rect();
                contentView.getWindowVisibleDisplayFrame(r);
                int heightDiff = contentView.getRootView().getHeight() - (r.bottom - r.top);
                if (heightDiff > 100) 
                    isKeyboardVisible = true;
                else
                    isKeyboardVisible = false;
             });
         }
    }

    public void closeKeyboardIfOpen()
    {
        InputMethodManager imm;
        imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
        if (isKeyboardVisible)
            imm.toggleSoftInput(InputMethodManager.HIDE_IMPLICIT_ONLY, 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);
    }
}

这对我很有用

InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
    if (imm.isActive())
        imm.toggleSoftInput(InputMethodManager.HIDE_IMPLICIT_ONLY, 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 )
}