小编wil*_*lek的帖子

我必须向Web服务发送请求,以使用用户名和密码对用户进行身份验证.

我对以下帖子请求有疑问:

public String postTest(String action, ConnectionParametrData [] parameters) {
        Uri.Builder builder = new Uri.Builder().scheme(scheme).authority(authority).path(action);
        uri = builder.build();
        BufferedReader in = null;
        String ans = null;
        HttpPost request = new HttpPost(uri.toString());
        HttpClient defaultClient = new DefaultHttpClient();
        try {
            request.setHeader("Content-Type", "application/x-www-form-urlencoded");
            request.setEntity(new UrlEncodedFormEntity(getValuePairs(parameters)));
            HttpResponse response = defaultClient.execute(request);
            in = new BufferedReader(new InputStreamReader(response.getEntity().getContent(), "UTF-8"), 8192);
            StringBuffer sb = new StringBuffer("");
            String line = "";
            String newLine = System.getProperty("line.separator");
            while((line = in.readLine()) != null) {
                sb.append(line + newLine);
            }
            ans = sb.toString();
        } …

我有一个有2页的viewpager,在每个片段上我放了一个按钮来切换片段,但如果我改变方向切换不起作用.使用我的OnChangePageButtonClick界面切换片段I为什么会发生这种情况？

ViewPager活动:

public class ViewPagerMusic extends FragmentActivity implements OnChangePageButtonClick {

    private ViewPager vp;

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

        ViewPagerAdapter viewPagerAdapter = new ViewPagerAdapter(super.getSupportFragmentManager(), fragments);

        vp = (ViewPager)findViewById(R.id.viewpager);
        vp.setAdapter(viewPagerAdapter);
    }

    private class ViewPagerAdapter extends FragmentStatePagerAdapter {

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

        @Override
    public Fragment getItem(int position) {
        switch(position) {
            case 0:
                MainPage mainPage = new MainPage();
                mainPage.setOnChengeButtonListener(ViewPagerMusic.this);
                return mainPage;
            case 1:
                PlaylistPage playlistPage = new PlaylistPage();
                playlistPage.setOnChengeButtonListener(ViewPagerMusic.this);
                return playlistPage;
        }
        return null;
    }

        @Override
        public int getCount() …