代码片段……

public void hideKeyboard(Context activityContext){

    InputMethodManager imm = (InputMethodManager)
            activityContext.getSystemService(Context.INPUT_METHOD_SERVICE);

    //android.R.id.content ( http://stackoverflow.com/a/12887919/2077479 )
    View rootView = ((Activity) activityContext)
            .findViewById(android.R.id.content).getRootView();

    imm.hideSoftInputFromWindow(rootView.getWindowToken(), 0);
}

public void showKeyboard(Context activityContext, final EditText editText){

    final InputMethodManager imm = (InputMethodManager)
            activityContext.getSystemService(Context.INPUT_METHOD_SERVICE);

    if (!editText.hasFocus()) {
        editText.requestFocus();
    }

    editText.post(new Runnable() {
        @Override
        public void run() {
            imm.showSoftInput(editText, InputMethodManager.SHOW_FORCED);
        }
    });
}

你可以试着强迫软键盘出现，这对我来说是有效的:

...
dialog.show();
input.requestFocus();
InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
imm.toggleSoftInput(InputMethodManager.SHOW_FORCED, 0);

我在各种不同的情况下都有同样的问题，我发现的解决方案在一些情况下工作，但在其他情况下不工作，所以这里是一个在我发现的大多数情况下工作的组合解决方案:

public static void showVirtualKeyboard(Context context, final View view) {
    if (context != null) {
        final InputMethodManager imm =  (InputMethodManager) context.getSystemService(Context.INPUT_METHOD_SERVICE);
        view.clearFocus();

        if(view.isShown()) {
            imm.showSoftInput(view, 0);
            view.requestFocus();
        } else {
            view.addOnAttachStateChangeListener(new View.OnAttachStateChangeListener() {
                @Override
                public void onViewAttachedToWindow(View v) {
                    view.post(new Runnable() {
                        @Override
                        public void run() {
                            view.requestFocus();
                            imm.showSoftInput(view, 0);
                        }
                    });

                    view.removeOnAttachStateChangeListener(this);
                }

                @Override
                public void onViewDetachedFromWindow(View v) {
                    view.removeOnAttachStateChangeListener(this);
                }
            });
        }
    }
}

您还可以创建EditText的自定义扩展，该扩展在接收到焦点时知道打开软键盘。这就是我最后要做的。以下是对我有效的方法:

public class WellBehavedEditText extends EditText {
    private InputMethodManager inputMethodManager;
    private boolean showKeyboard = false;

    public WellBehavedEditText(Context context) {
        super(context);
        this.initializeWellBehavedEditText(context);
    }

    public WellBehavedEditText(Context context, AttributeSet attributes) {
        super(context, attributes);
        this.initializeWellBehavedEditText(context);
    }

    public WellBehavedEditText(Context context, AttributeSet attributes, int defStyleAttr) {
        super(context, attributes, defStyleAttr);
        this.initializeWellBehavedEditText(context);
    }

    public WellBehavedEditText(Context context, AttributeSet attributes, int defStyleAttr, int defStyleRes) {
        super(context, attributes, defStyleAttr, defStyleRes);
        this.initializeWellBehavedEditText(context);
    }

    private void initializeWellBehavedEditText(Context context) {
        this.inputMethodManager = (InputMethodManager)context.getSystemService(Context.INPUT_METHOD_SERVICE);

        final WellBehavedEditText editText = this;
        this.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                if(showKeyboard) {
                    showKeyboard = !(inputMethodManager.showSoftInput(editText, InputMethodManager.SHOW_FORCED));
                }
            }
        });
    }

    @Override
    protected void onFocusChanged(boolean focused, int direction, Rect previouslyFocusedRect) {
        if(!focused) this.showKeyboard = false;
        super.onFocusChanged(focused, direction, previouslyFocusedRect);
    }

    @Override
    public boolean requestFocus(int direction, Rect previouslyFocusedRect) {
        boolean result = super.requestFocus(direction, previouslyFocusedRect);
        this.showKeyboard = true;
        final WellBehavedEditText self = this;
        this.post(new Runnable() {
            @Override
            public void run() {
                showKeyboard = !(inputMethodManager.showSoftInput(self, InputMethodManager.SHOW_FORCED));
            }
        });
        return result;
    }
}

当其他方法都不起作用时，就强制显示它:

editText.requestFocus();
InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
imm.toggleSoftInput(InputMethodManager.SHOW_FORCED, InputMethodManager.HIDE_IMPLICIT_ONLY);

然后，如果你想关闭它，例如在onPause()中，你可以调用:

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

对于Kotlin，只需使用以下扩展:

fun EditText.showKeyboard() {
    val imm = context.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
    imm.showSoftInput(this, InputMethodManager.SHOW_IMPLICIT)
}

fun EditText.hideKeyboard() {
    val imm = context.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
    imm.hideSoftInputFromWindow(this.windowToken, 0)
}