ActionBarSherlock 和 FragmentTabsPager

正如很多人到目前为止所做的那样，我正在将 FragmentTabsPager 实现到我的应用程序中，该应用程序使用 ActionBarSherlock 4.0。然而，我迷路了。

碎片，以及谷歌围绕它的所有小想法、计划和方法，都让我感到困惑。如果有人可以看一下我的代码并引导我完成这个过程，并提供帮助使其工作，我将感谢他们一千次：D。

我有另一个项目，以 ViewPager 开始，但选项卡混合得更好，尤其是它们位于横向和平板电脑上的 ActionBar 中。

我的代码已全部压缩并准备好在这里：http://dl.dropbox.com/u/21807195/Antonius%20College%202.zip http://dl.dropbox.com/u/21807195/Antonius%20College%202.zip

提前致谢！

我将向您展示我的代码，其中包含 ViewPager、TabListener 以及链接到每个选项卡的 Fragments 系统。它实现了 ABS，但到目前为止，在 Gingerbread 及更低版本上仍然会崩溃（不过在 ICS 上工作得很好）：

import java.util.ArrayList;
import library.DatabaseHandler;
import org.json.JSONObject;
import com.actionbarsherlock.R;
import com.actionbarsherlock.app.ActionBar;
import com.actionbarsherlock.app.ActionBar.Tab;
import com.actionbarsherlock.app.SherlockFragmentActivity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.MenuItem.OnMenuItemClickListener;
import android.view.View.OnClickListener;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Switch;
import android.widget.TextView;
import android.widget.Toast;
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.app.FragmentTransaction;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;

public class Polling extends SherlockFragmentActivity {
    private ViewPager mViewPager;
    private TabsAdapter mTabsAdapter;
    private final static String TAG = "21st Polling:";

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        mViewPager = new ViewPager(this);
        mViewPager.setId(R.id.pager);
        setContentView(mViewPager);
        ActionBar bar = getSupportActionBar();
        bar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
        bar.setDisplayShowTitleEnabled(false);
        bar.setDisplayShowHomeEnabled(false);

        mTabsAdapter = new TabsAdapter(this, mViewPager);
        mTabsAdapter.addTab(bar.newTab().setText(R.string.login),
                LoginFragment.class, null);
        mTabsAdapter.addTab(bar.newTab().setText(R.string.economics),
                EconFragment.class, null);
        mTabsAdapter.addTab(bar.newTab().setText(R.string.elections),
                ElectionsFragment.class, null);
        mTabsAdapter.addTab(bar.newTab().setText(R.string.politics),
                PoliticsFragment.class, null);
        mTabsAdapter.addTab(bar.newTab().setText(R.string.science),
                ScienceFragment.class, null);
        mTabsAdapter.addTab(bar.newTab().setText(R.string.finance),
                FinanceFragment.class, null);
        mTabsAdapter.addTab(bar.newTab().setText(R.string.religion),
                ReligionFragment.class, null);
        mTabsAdapter.addTab(bar.newTab().setText(R.string.military),
                MilitaryFragment.class, null);
        mTabsAdapter.addTab(bar.newTab().setText(R.string.international),
                InternationalFragment.class, null); 
        Log.v(TAG, (String)bar.getTabAt(0).getText());

    }
public static class TabsAdapter extends FragmentPagerAdapter
    implements ActionBar.TabListener, ViewPager.OnPageChangeListener {
        private final Context mContext;
        private final ActionBar mActionBar;
        private final ViewPager mViewPager;
        private final ArrayList<TabInfo> mTabs = new ArrayList<TabInfo>();

        static final class TabInfo {
            private final Class<?> clss;
            private final Bundle args;

            TabInfo(Class<?> _class, Bundle _args) {
                clss = _class;
                args = _args;
            }
        }

        public TabsAdapter(SherlockFragmentActivity activity, ViewPager pager) {
            super(activity.getSupportFragmentManager());
            mContext = activity;
            mActionBar = activity.getSupportActionBar();
            mViewPager = pager;
            mViewPager.setAdapter(this);
            mViewPager.setOnPageChangeListener(this);
        }

        public void addTab(ActionBar.Tab tab, Class<?> clss, Bundle args) {
            TabInfo info = new TabInfo(clss, args);
            tab.setTag(info);
            tab.setTabListener(this);
            mTabs.add(info);
            mActionBar.addTab(tab);
            notifyDataSetChanged();
        }


        public int getCount() {
            return mTabs.size();
        }

        public SherlockFragment getItem(int position) {
            TabInfo info = mTabs.get(position);
            return (SherlockFragment)Fragment.instantiate(mContext, info.clss.getName(), info.args);
        }


        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
        }


        public void onPageSelected(int position) {
            mActionBar.setSelectedNavigationItem(position);
        }


        public void onPageScrollStateChanged(int state) {
        }


        public void onTabSelected(Tab tab, FragmentTransaction ft) {
            mViewPager.setCurrentItem(tab.getPosition());
            //Log.v(TAG, "clicked");
            Object tag = tab.getTag();
            for (int i=0; i<mTabs.size(); i++) {
                if (mTabs.get(i) == tag) {
                    mViewPager.setCurrentItem(i);
                }
            }
        }

        public void onTabUnselected(Tab tab, FragmentTransaction ft) {}

        public void onTabReselected(Tab tab, FragmentTransaction ft) {}

        public void onTabReselected(Tab tab, android.app.FragmentTransaction ft) {}

        public void onTabUnselected(Tab tab, android.app.FragmentTransaction ft) {}
    }

下面是一个片段的样子：

package com.davekelley.polling;

import com.actionbarsherlock.R;
import com.actionbarsherlock.app.SherlockFragment;

import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class MilitaryFragment extends SherlockFragment {

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        return inflater.inflate(R.layout.militaryfragment, container, false);
    }
}

我的最后一点是，我的代码仍然存在另一个问题：在用户按回键后，各个片段并不总是重新加载其界面（这会导致从屏幕上删除整个应用程序，无论它们位于哪个选项卡/片段上，因为我有没有backStack）。这就是我现在正在努力的事情。我想一旦我解决了这个问题，我就会尝试找出为什么我仍然没有让 Gingerbread 执行正常运行。无论哪种方式，我希望浏览这段代码对您有所帮助。

这是一个带有一些 onClickListeners 的片段：

import com.actionbarsherlock.R;
import com.actionbarsherlock.app.SherlockFragment;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Context;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TableLayout;
import android.widget.TableRow;
import android.widget.TextView;
import android.widget.Toast;

public class LoginFragment extends SherlockFragment {

    Button loginButton;
    Button registerButton;
    Polling activity;

    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.loginfragment, container, false);

        return v;
    }

    public void onResume() {
        super.onResume();
        Log.d("Econ", "onresume");

        loginButton = (Button) getActivity().findViewById(R.id.loginButton);
        loginButton.setOnClickListener(loginListener);
        registerButton = (Button) getActivity().findViewById(R.id.registerButton);
        registerButton.setOnClickListener(registerListener);

    }

    public OnClickListener loginListener = new OnClickListener() {
        @Override
        public void onClick(View v) {

            if(loginButton.getText().toString() == "Log Out") {

                activity.loginReport(2);
                loginButton.setText(R.string.login);
                //Remove user from dB sqllite when I know how
            }
            else {
            Log.v("LoginF", "onclick");
            ProgressDialog progressDialog = new ProgressDialog(getActivity());
            progressDialog.setMessage("Logging in...");
            LoginTask loginTask = new LoginTask((Polling) getActivity(), progressDialog);
            loginTask.execute();
            }
        }
    };


    public OnClickListener registerListener = new OnClickListener() {
        @Override
        public void onClick(View v) {


            Log.v("Register", "onclick");
            ProgressDialog progressDialog = new ProgressDialog(getActivity());
            progressDialog.setMessage("Registering new user...");
            RegisterTask registerTask = new RegisterTask((Polling) getActivity(), progressDialog);
            registerTask.execute();
            }

    };

    public void onAttach(Activity activity) {
        super.onAttach(activity);
        this.activity = (Polling) activity;
    }

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);


    }

    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
    }

    public void onStart() {
        super.onStart();
        Log.d("Econ", "onstart");
    }


    public void onPause() {
        super.onPause();Log.d("Econ", "onpause");
    }

    public void onStop() {
        super.onStop();
        Log.d("Econ", "onstop");
    }

    public void onDestroyView() {
        super.onDestroyView();
        Log.d("Econ", "ondestroyview");
    }

    public void onDestroy() {
        super.onDestroy();
        Log.d("Econ", "ondestroy");

    }

    public void onDetach() {
        super.onDetach();
        Log.d("Econ", "ondetach");
    }

}

您看到的 loginTask 对象实际上是扩展 ASyncTask 的类 - 它们处理连接到我的服务器并注册/登录。

我认为添加一点代码会很有帮助。这是我的另一个片段，就像 LoginFragment 一样，但它的 UI 扩展略有不同。最终，您在下面的 while 循环中看到的内容将进入 ASyncTask 以从服务器获取每个问题，而不是您看到的虚拟字符串数组：

public class EconFragment extends SherlockFragment {

    private TableLayout questionContainer;
    int pos = 0;
    private String[] titles = {"The first title ", "hallo1","hallo2", "hallo3",
            "hallo4", "hallo5","hallo6", "hallo7","hallo8", "hallo9"};

    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        Log.v("Econ", "onCreateView");
        View v = inflater.inflate(R.layout.econfragment, container, false);
        questionContainer = (TableLayout) v.findViewById(R.id.questionContainer);
        //bs
        int leftMargin=5;
        int topMargin=5;
        int rightMargin=5;
        int bottomMargin=5;
        while (pos < 10) {
        View question = inflater.inflate(R.layout.question, null);
        question.setId(pos);
        TextView title = (TextView) question.findViewById(R.id.questionTextView);
        title.setText(titles[pos]);
        Button charts = (Button) question.findViewById(R.id.chartsButton);
        charts.setId(pos);
        charts.setOnClickListener(chartsListener);
        TableRow tr = (TableRow) question;
        TableLayout.LayoutParams trParams = new TableLayout.LayoutParams(
                TableLayout.LayoutParams.MATCH_PARENT,
                TableLayout.LayoutParams.WRAP_CONTENT);
        trParams.setMargins(leftMargin, topMargin, rightMargin, bottomMargin);
        tr.setLayoutParams(trParams);
        Log.v("econ", "while loop");
        questionContainer.addView(tr);
        pos++;
        }
        pos = 0;
        return v;
    }