java - 无法解析符号 setOnPageChangeListener

Question

我找不到任何与我的场景相关的解决方案。我正在努力在选项卡滑动上手动选择受尊重的选项卡。我正在学习

http://www.androidgreeve.com/2014/01/android-actionbar-navigating-with-swipeable-tabs-and-views.html

在 MainActivity 中，在添加 viewPager.setOnPageChangeListener 时它无法识别它......它会报错......

cannot resolve symbol setOnPageChangeListener

这是代码

package com.example.administrator.fragmentsexample;

import android.support.v7.app.ActionBar;
import android.support.v4.view.ViewPager;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;

import com.example.administrator.adapter.TabsPagerAdapter;

public class MainActivity extends AppCompatActivity implements
        ActionBar.TabListener {

    private ViewPager viewPager;
    private TabsPagerAdapter mAdapter;
    private ActionBar actionBar;
    // Tab titles
    private String[] tabs = {"Social", "Organizer", "Movies"};

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Initilization
        viewPager = (ViewPager) findViewById(R.id.pager);
        actionBar = getSupportActionBar();
        mAdapter = new TabsPagerAdapter(getSupportFragmentManager());
        viewPager.setAdapter(mAdapter);
        actionBar.setHomeButtonEnabled(false);
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

        // Adding Tabs
        for (String tab_name : tabs) {
            actionBar.addTab(actionBar.newTab().setText(tab_name)
                    .setTabListener(this));

        }
    }

    @Override
    public void onTabSelected(ActionBar.Tab tab, android.support.v4.app.FragmentTransaction fragmentTransaction) {

    }

    @Override
    public void onTabUnselected(ActionBar.Tab tab, android.support.v4.app.FragmentTransaction fragmentTransaction) {

    }

    @Override
    public void onTabReselected(ActionBar.Tab tab, android.support.v4.app.FragmentTransaction fragmentTransaction) {

    }

    viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {

        @Override
        public void onPageSelected(int position) {
            // on changing the page
            // make respected tab selected
            actionBar.setSelectedNavigationItem(position);
        }

        @Override
        public void onPageScrolled(int arg0, float arg1, int arg2) {
        }

        @Override
        public void onPageScrollStateChanged(int arg0) {
        }
    });

}

我错过了什么？

Answer 1

试着移动这个:

viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {

    @Override
    public void onPageSelected(int position) {
        // on changing the page
        // make respected tab selected
        actionBar.setSelectedNavigationItem(position);
    }

    @Override
    public void onPageScrolled(int arg0, float arg1, int arg2) {
    }

    @Override
    public void onPageScrollStateChanged(int arg0) {
    }
});

进入onCreate。我认为当前的通话安排没有意义。 :-)