Question

我是android编程的初学者，我使用的是eclipse luna。我创建了一个新活动，我选择了Tabbed Activity而不是Blank活动。它已经有刷卡代码。但是有些代码我无法理解。当我刷卡时，我不知道如何改变活动。在案例中，我想知道为什么它是字符串而不是活动的引用。

这是来自标签式活动的代码：

package com.e_learningforchildren.sarah;

import java.util.Locale;

import android.support.v7.app.ActionBarActivity;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.os.Bundle;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;

public class TopicsActivity extends ActionBarActivity {

/**
 * The {@link android.support.v4.view.PagerAdapter} that will provide
 * fragments for each of the sections. We use a {@link FragmentPagerAdapter}
 * derivative, which will keep every loaded fragment in memory. If this
 * becomes too memory intensive, it may be best to switch to a
 * {@link android.support.v4.app.FragmentStatePagerAdapter}.
 */
SectionsPagerAdapter mSectionsPagerAdapter;

/**
 * The {@link ViewPager} that will host the section contents.
 */
ViewPager mViewPager;

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

    // Create the adapter that will return a fragment for each of the three
    // primary sections of the activity.
    mSectionsPagerAdapter = new SectionsPagerAdapter(
            getSupportFragmentManager());

    // Set up the ViewPager with the sections adapter.
    mViewPager = (ViewPager) findViewById(R.id.pager);
    mViewPager.setAdapter(mSectionsPagerAdapter);

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.topics, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}

/**
 * A {@link FragmentPagerAdapter} that returns a fragment corresponding to
 * one of the sections/tabs/pages.
 */
public class SectionsPagerAdapter extends FragmentPagerAdapter {

    public SectionsPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        // getItem is called to instantiate the fragment for the given page.
        // Return a PlaceholderFragment (defined as a static inner class
        // below).
        return PlaceholderFragment.newInstance(position + 1);
    }

    @Override
    public int getCount() {
        // Show 3 total pages.
        return 3;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        Locale l = Locale.getDefault();
        switch (position) {
        case 0:
        return getString(R.string.title_section1).toUpperCase(l);

        case 1:
            return getString(R.string.title_section2).toUpperCase(l);
        case 2:
            return getString(R.string.title_section3).toUpperCase(l);
        }
        return null;
    }
}

/**
 * A placeholder fragment containing a simple view.
 */
public static class PlaceholderFragment extends Fragment {
    /**
     * The fragment argument representing the section number for this
     * fragment.
     */
    private static final String ARG_SECTION_NUMBER = "section_number";

    /**
     * Returns a new instance of this fragment for the given section number.
     */
    public static PlaceholderFragment newInstance(int sectionNumber) {
        PlaceholderFragment fragment = new PlaceholderFragment();
        Bundle args = new Bundle();
        args.putInt(ARG_SECTION_NUMBER, sectionNumber);
        fragment.setArguments(args);
        return fragment;
    }

    public PlaceholderFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_topics,
                container, false);
        return rootView;
    }
}

}

Answer 1

这是我的带有片段的滑动标签代码不包括进口

 public class MainActivity extends FragmentActivity {

    ViewPager viewpager;
    ActionBar actionbar;
    String[] tabs={"temperature","information"};
    tabpageadapter adapterm;




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

        viewpager=( ViewPager)findViewById(R.id.pager);

        actionbar=getActionBar();

        adapterm= new tabpageadapter(getSupportFragmentManager());

        viewpager.setAdapter(adapterm);

        actionbar.setHomeButtonEnabled(false);
        actionbar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

       actionbar.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#1F2230")));

       actionbar.setStackedBackgroundDrawable(new ColorDrawable(Color.parseColor("#323445")));


        for(String tabb:tabs)
        {
            actionbar.addTab(actionbar.newTab().setText(tabb).setTabListener(this));
        }


        viewpager.setOnPageChangeListener(this);




    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
}

这是viewpager的页面适配器

public class tabpageadapter extends FragmentPagerAdapter{

public tabpageadapter(FragmentManager fm) {
    super(fm);
    // TODO Auto-generated constructor stub
}

@Override
public Fragment getItem(int index) {
    // TODO Auto-generated method stub
    switch(index)

    {
    case 0:
        return new temperature_fragment();

    case 1:
        return new information_fragment();




    }


    return null;
}

@Override
public int getCount() {
    // TODO Auto-generated method stub
    return 2;
}

}

这些是一个片段文件，只需创建另一个带有diff名称的文件，这样就可以使用2个标签

public class temperature_fragment extends Fragment{

    TextView tvtemp,farenhit;


    LinearLayout llfortemp;
    Intent inte;

    BatteryManager bm;
    double i,j;
    int l,k;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // TODO Auto-generated method stub

        View rootview=inflater.inflate(R.layout.temperature_xml, container,false);


        Context cc=getActivity();

        tvtemp=(TextView)rootview.findViewById(R.id.texttemp);
        farenhit=(TextView)rootview.findViewById(R.id.textViewfarenhit);
        llfortemp=(LinearLayout)rootview.findViewById(R.id.llfortemp);






        return rootview;
    }











        }

Answer 2

实际上你没有滑动活动你只是刷一个片段而字符串就是你的页面标题。

我认为您应该了解片段以及如何管理片段或替换它们。

为您添加链接 http://developer.android.com/guide/components/fragments.html

Answer 3

如果您刚刚开始，我建议您不要先使用滑动示例，滑动是针对＆＃34;片段＆＃34;不是＆＃34;活动＆＃34;如果您是Android开发的初学者，这是非常先进的主题。

我建议你阅读本教程，因为它会教你所有你需要了解的活动，碎片，动作栏，菜单，布局组件......等等。最后你会有一个你需要建立的坚实基础。（因为你正在使用Eclipse，忽略关于命令行的部分）。

https://developer.android.com/training/basics/firstapp/creating-project.html

希望这会有所帮助，祝你好运。

使用选项卡式活动进行滑动

3 个答案: