android 监听软键盘的收起与打开

参考: http://toughcoder.net/blog/2015/10/09/android-trick-detect-soft-keyboard-show-slash-hide/

package xiamai.testidea;

import android.app.Activity;
import android.graphics.Rect;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewTreeObserver;

/**
 * Created by Administrator on 2016/6/15.
 */
public class BaseActivity extends Activity
{
    private OnKeyboardListener keyboardListener;
    private boolean     keyboardVisible = false;
    private ViewTreeObserver.OnGlobalLayoutListener globalLayoutListener = new ViewTreeObserver.OnGlobalLayoutListener()
    {
        @Override
        public void onGlobalLayout()
        {
            if (keyboardIsVisible(getRootView()))
            {
                if (!keyboardVisible)
                {
                    keyboardVisible = true;
                    keyboardListener.onKeyboardShow();
                }
            }
            else
            {
                if (keyboardVisible)
                {
                    keyboardVisible = false;
                    keyboardListener.onKeyboardHidden();
                }
            }
        }
    };

    public View getRootView()
    {
        return ((ViewGroup)findViewById(android.R.id.content)).getChildAt(0);
    }

    protected void setOnKeyboardListener(OnKeyboardListener keyboardListener)
    {
        this.keyboardListener = keyboardListener;
        getRootView().getViewTreeObserver().addOnGlobalLayoutListener(globalLayoutListener);
    }

    private boolean keyboardIsVisible(View rootView)
    {
        final int softKeyboardHeight = 100;
        Rect r = new Rect();
        rootView.getWindowVisibleDisplayFrame(r);
        DisplayMetrics dm = rootView.getResources().getDisplayMetrics();
        int heightDiff = rootView.getBottom() - r.bottom;
        return heightDiff > softKeyboardHeight * dm.density;
    }

    public interface OnKeyboardListener
    {
        void onKeyboardShow();
        void onKeyboardHidden();
    }
}

package xiamai.testidea;

import android.os.Bundle;
import android.util.Log;

/**
 * Created by Administrator on 2016/7/11.
 */
public class KeyboardTestActivity extends BaseActivity
    implements BaseActivity.OnKeyboardListener
{
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.root_activity);
        setOnKeyboardListener(this);
    }

    @Override
    public void onKeyboardShow()
    {
        Log.e("KeyboardEvent", "键盘打开");
    }

    @Override
    public void onKeyboardHidden()
    {
        Log.e("KeyboardEvent", "键盘关闭");
    }
}