Java SwipeyTabsSampleActivity如何不生成编译错误?
我正试图从年开发的SwipeyTabsSampleActivity中提取另一个样本 这是示例代码,我的问题是为什么在方法getTab->view.setOnClickListener中引用两个变量“mviewpage”和“position”时没有得到编译错误 下面是完整的示例源代码。我首先尝试了示例代码,它编译得很好,运行得很好,但我不知道如何根据需要定制示例。一切都进行得很顺利(编译和运行),但当我打算设置onClickListener并引用这两个变量时,出现了以下两个编译错误 1-无法对非静态字段mViewPager进行静态引用 2-不能引用在不同方法中定义的内部类中的非最终变量位置 我认为这两个错误应该出现在示例代码中,不仅是我的代码,而且我不知道为什么Java SwipeyTabsSampleActivity如何不生成编译错误?,java,android,Java,Android,我正试图从年开发的SwipeyTabsSampleActivity中提取另一个样本 这是示例代码,我的问题是为什么在方法getTab->view.setOnClickListener中引用两个变量“mviewpage”和“position”时没有得到编译错误 下面是完整的示例源代码。我首先尝试了示例代码,它编译得很好,运行得很好,但我不知道如何根据需要定制示例。一切都进行得很顺利(编译和运行),但当我打算设置onClickListener并引用这两个变量时,出现了以下两个编译错误 1-无法对非静
/*
* Copyright 2011 Peter Kuterna
*
* 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 net.peterkuterna.android.apps.swipeytabs;
import android.content.Context;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.TextView;
public class SwipeyTabsSampleActivity extends FragmentActivity {
private static final String [] TITLES = {
"CATEGORIES",
"FEATURED",
"TOP PAID",
"TOP FREE",
"TOP GROSSING",
"TOP NEW PAID",
"TOP NEW FREE",
"TRENDING",
};
private SwipeyTabs mTabs;
private ViewPager mViewPager;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_swipeytab);
mViewPager = (ViewPager) findViewById(R.id.viewpager);
mTabs = (SwipeyTabs) findViewById(R.id.swipeytabs);
SwipeyTabsPagerAdapter adapter = new SwipeyTabsPagerAdapter(this,
getSupportFragmentManager());
mViewPager.setAdapter(adapter);
mTabs.setAdapter(adapter);
mViewPager.setOnPageChangeListener(mTabs);
mViewPager.setCurrentItem(0);
}
private class SwipeyTabsPagerAdapter extends FragmentPagerAdapter implements
SwipeyTabsAdapter {
private final Context mContext;
public SwipeyTabsPagerAdapter(Context context, FragmentManager fm) {
super(fm);
this.mContext = context;
}
@Override
public Fragment getItem(int position) {
return SwipeyTabFragment.newInstance(TITLES[position]);
}
@Override
public int getCount() {
return TITLES.length;
}
public TextView getTab(final int position, SwipeyTabs root) {
TextView view = (TextView) LayoutInflater.from(mContext).inflate(
R.layout.swipey_tab_indicator, root, false);
view.setText(TITLES[position]);
view.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
mViewPager.setCurrentItem(position);
}
});
return view;
}
}
}
getTab()
是swipeytabsampleactivity
的非静态内部类的实例方法,因此它具有对其外部类实例的隐式引用,并且可以访问此实例的所有字段和方法,从而访问mviewpage
。OnclickListener
是SwipeyTabsSampleActivity
内部类的匿名内部类,因此也可以访问其两个外部类实例的所有字段和方法
如果内部类是静态的,它就不会编译。如果mviewpage
是getTab()
方法的非最终局部变量,它也不会编译