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");
     }
 }