工具类：获取KeyBoard高度以及判断KeyBoard是否显示

import android.app.Activity;
import android.content.Context;
import android.graphics.Rect;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewTreeObserver;

public class KeyBoardUtil {
    public static void attach(final Activity activity, final KeyBoardListener keyBoardListener) {
        final ViewGroup contentView = (ViewGroup) activity.findViewById(android.R.id.content);
        final int statusBarHeight = getStatusHeight(activity);

        contentView.getViewTreeObserver().addOnGlobalLayoutListener(
                new ViewTreeObserver.OnGlobalLayoutListener() {
                    public int fullDisplayHeight;
                    boolean isKeyboardVisible;

                    @Override
                    public void onGlobalLayout() {
                        ViewGroup contentView = (ViewGroup) activity.findViewById(android.R.id.content);
                        View userRootView = contentView.getChildAt(0);
                        // 计算userRootView的高度
                        Rect r = new Rect();
                        userRootView.getWindowVisibleDisplayFrame(r);
                        int displayHeight = r.bottom - r.top;

                        if (fullDisplayHeight == 0) {
                            fullDisplayHeight = displayHeight;
                            return;
                        }
                        int keyboardHeight = Math.abs(displayHeight - fullDisplayHeight);
                        if (keyboardHeight == 0) {
                            if (isKeyboardVisible) {
                                isKeyboardVisible = false;
                                if (keyBoardListener != null)
                                    keyBoardListener.keyboardShowingChanged(isKeyboardVisible);
                            }
                            return;
                        }


                        // 当前变化由，非全屏到全屏导致，此时应该更新fullDisplayHeight
                        if (keyboardHeight == statusBarHeight) {
                            fullDisplayHeight = displayHeight;
                            return;
                        }

                        if (keyBoardListener != null)
                            keyBoardListener.keyboardHeight(keyboardHeight);

                        if (!isKeyboardVisible) {
                            isKeyboardVisible = true;
                            if (keyBoardListener != null)
                                keyBoardListener.keyboardShowingChanged(isKeyboardVisible);
                        }
                    }
                });
    }

    public interface KeyBoardListener {
        void keyboardHeight(int keyboardHeight);

        void keyboardShowingChanged(boolean visible);

    }

    /**
     * 获得状态栏的高度
     * 
     * @param context
     * @return
     */
    public static int getStatusHeight(Context context) {

        int statusHeight = -1;
        try {
            Class clazz = Class.forName("com.android.internal.R$dimen");
            Object object = clazz.newInstance();
            int height = Integer.parseInt(clazz.getField("status_bar_height")
                    .get(object).toString());
            statusHeight = context.getResources().getDimensionPixelSize(height);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return statusHeight;
    }

}