Android ActionBar中的按钮添加旋转动画

<?xml version="1.0" encoding="utf-8"?>
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<rotate xmlns:android="http://schemas.android.com/apk/res/android"
  android:duration="2000"
  android:fromDegrees="0"
  android:interpolator="@android:anim/linear_interpolator"
  android:pivotX="50%"
  android:pivotY="50%"
  android:toDegrees="360" />

package com.example.actionbarmenubtnrefresh;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.ImageView;
import android.widget.Toast;

public class MainActivity extends Activity {

    protected MenuItem refreshItem;
    
    private boolean isRefreshState = false;
    
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        //MenuInflater实例化Menu目录下的Menu布局文件
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        case R.id.action_refresh:
            refreshMenuItemView(item);
            Toast.makeText(getBaseContext(), "开始刷新", Toast.LENGTH_SHORT).show();
            break;
        case R.id.action_stop:
            hideRefreshAnimation();
            Toast.makeText(getBaseContext(), "停止刷新", Toast.LENGTH_SHORT).show();
            break;

        default:
            break;
        }
        return super.onOptionsItemSelected(item);
    }

    private void refreshMenuItemView(MenuItem item) {
        hideRefreshAnimation();
        refreshItem = item;
        
        //LayoutInflater实例化整个布局文件
        //使用ImageView设置成MenuItem的ActionView
        ImageView refreshView = (ImageView)getLayoutInflater().inflate(R.layout.refresh_view, null);
        refreshView.setImageResource(R.drawable.ic_action_refresh);
        refreshItem.setActionView(refreshView);
        //显示刷新动画
        Animation animation = AnimationUtils.loadAnimation(this, R.anim.refresh);
        //设置重复模式  Defines what this animation should do when it reaches the end
        animation.setRepeatMode(Animation.RESTART);
        //设置重复次数
        animation.setRepeatCount(Animation.INFINITE);
        //使用ImageView 显示旋转动画
        refreshView.startAnimation(animation);
        isRefreshState = true;
    }
    
    private void hideRefreshAnimation() {
        if (refreshItem != null) {
            View view = refreshItem.getActionView();
            if (view != null) {
                view.clearAnimation();
                refreshItem.setActionView(null);
                isRefreshState = false;
            }
        }
    }
    

}