按Back key把Activity关掉即使有键盘的时候
一般情况下，当键盘显示的时候，你按下back只会将键盘关掉，但有时候你想要不仅仅是把键盘关掉而已，还想把当前的activity/给关掉。那你可以重写你的activity的main view,下面的例子是我看QucikSearchBox ap中SearchActivityView.java。

/* * Copyright (C) 2010 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * *      http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */package com.android.quicksearchbox.ui;import android.app.Activity;import android.content.Context;import android.util.AttributeSet;import android.view.KeyEvent;import android.view.inputmethod.InputMethodManager;import android.widget.RelativeLayout;/** * Finishes the containing activity on BACK, even if input method is showing. */public class SearchActivityView extends RelativeLayout {    public SearchActivityView(Context context) {        super(context);    }    public SearchActivityView(Context context, AttributeSet attrs) {        super(context, attrs);    }    public SearchActivityView(Context context, AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);    }    private Activity getActivity() {        Context context = getContext();        if (context instanceof Activity) {            return (Activity) context;        } else {            return null;        }    }    /**     * Hides the input method.     */    protected void hideInputMethod() {        InputMethodManager imm = (InputMethodManager)                getContext().getSystemService(Context.INPUT_METHOD_SERVICE);        if (imm != null) {            imm.hideSoftInputFromWindow(getWindowToken(), 0);        }    }    /**     * Overrides the handling of the back key to dismiss the activity.     */    @Override    public boolean dispatchKeyEventPreIme(KeyEvent event) {        Activity activity = getActivity();        if (activity != null && event.getKeyCode() == KeyEvent.KEYCODE_BACK) {            KeyEvent.DispatcherState state = getKeyDispatcherState();            if (state != null) {                if (event.getAction() == KeyEvent.ACTION_DOWN                        && event.getRepeatCount() == 0) {                    state.startTracking(event, this);                    return true;                } else if (event.getAction() == KeyEvent.ACTION_UP                        && !event.isCanceled() && state.isTracking(event)) {                    hideInputMethod();                    activity.onBackPressed();                    return true;                }            }        }        return super.dispatchKeyEventPreIme(event);    }}

监测到按下bakc key之后hideInputMethod();隐藏键盘activity.onBackPressed();关闭Activity.这样达到的效果是：但你在SearchActivity中按下bakc之后就会退出这个acitvity,不管键盘是否显示。
怎么会不和谐呢？怎样个不和谐呢？有这个KeyEvent.KEYCODE_BACK判断吗？