Question

我一直在研究如何使用制表符完成一项活动，并且已经接近完成。不幸的是，我遇到了一些障碍。

在遵循了一个很好的指导之后，我创建了一个带有tabLayout和ViewPager的交互式活动来显示片段。

每个选项卡都显示相同的布局，左侧是一列TextView，保留其默认值，另一列是需要从不同位置获取其值的TextView。

作为测试，我让每个选项卡向其各自的TextView发送不同的文本值（示例选项卡＃1被分配为使用“楼下”，＃2被分配为使用“楼上”）-通过onTabSelected侦听器完成

我遇到的问题是将文本分配给TextViews。选择选项卡时，它永远不会显示。有时会显示在我打开的下一个标签上。在打开选项卡3之前，我已经打开选项卡2之后，有时它还会在选项卡3中显示选项卡1分配值。

我使用setText（）时，我处理过的其他所有TextView都会立即进行更新。但是，我对使用Tab活动非常陌生，所以我很可能会搞砸一些东西。

Distribution.java

package local.mobileapps.bryandouglas.supremeshoppinglist;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.os.Bundle;
import android.support.design.widget.TabLayout;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;

public class Distribution extends FragmentActivity {
    private Context context;
    private TabLayout tabLayout;
    private ViewPager viewPager;

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

        context = this;

        viewPager = (ViewPager) findViewById(R.id.viewpager);
        ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
        viewPager.setAdapter(adapter);

        tabLayout = (TabLayout) findViewById(R.id.tabs);
        tabLayout.setupWithViewPager(viewPager);

        tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
            @Override
            public void onTabSelected(TabLayout.Tab tab) {
                switch (tab.getPosition()) {
                    case 0:
                        TabFragment.cream.setText("Downstairs");
                        TabFragment.freshnessBottles.setText("Downstairs");
                        TabFragment.soap.setText("Downstairs");
                        TabFragment.paperCups.setText("Downstairs");
                        TabFragment.shortStirSticks.setText("Downstairs");
                        TabFragment.longStirSticks.setText("Downstairs");
                        TabFragment.cafeRoyale.setText("Downstairs");
                        TabFragment.hotChocolate.setText("Downstairs");
                        TabFragment.equal.setText("Downstairs");
                        TabFragment.sugar.setText("Downstairs");
                        TabFragment.greenTea.setText("Downstairs");
                        TabFragment.orangePekoe.setText("Downstairs");
                        break;

                    case 1:
                        TabFragment.cream.setText("Upstairs");
                        TabFragment.freshnessBottles.setText("Upstairs");
                        TabFragment.soap.setText("Upstairs");
                        TabFragment.paperCups.setText("Upstairs");
                        TabFragment.shortStirSticks.setText("Upstairs");
                        TabFragment.longStirSticks.setText("Upstairs");
                        TabFragment.cafeRoyale.setText("Upstairs");
                        TabFragment.hotChocolate.setText("Upstairs");
                        TabFragment.equal.setText("Upstairs");
                        TabFragment.sugar.setText("Upstairs");
                        TabFragment.greenTea.setText("Upstairs");
                        TabFragment.orangePekoe.setText("Upstairs");
                        break;

                    case 2:
                        TabFragment.cream.setText("Shipping");
                        TabFragment.freshnessBottles.setText("Shipping");
                        TabFragment.soap.setText("Shipping");
                        TabFragment.paperCups.setText("Shipping");
                        TabFragment.shortStirSticks.setText("Shipping");
                        TabFragment.longStirSticks.setText("Shipping");
                        TabFragment.cafeRoyale.setText("Shipping");
                        TabFragment.hotChocolate.setText("Shipping");
                        TabFragment.equal.setText("Shipping");
                        TabFragment.sugar.setText("Shipping");
                        TabFragment.greenTea.setText("Shipping");
                        TabFragment.orangePekoe.setText("Shipping");
                        break;

                    case 3:
                        TabFragment.cream.setText("Solutions");
                        TabFragment.freshnessBottles.setText("Solutions");
                        TabFragment.soap.setText("Solutions");
                        TabFragment.paperCups.setText("Solutions");
                        TabFragment.shortStirSticks.setText("Solutions");
                        TabFragment.longStirSticks.setText("Solutions");
                        TabFragment.cafeRoyale.setText("Solutions");
                        TabFragment.hotChocolate.setText("Solutions");
                        TabFragment.equal.setText("Solutions");
                        TabFragment.sugar.setText("Solutions");
                        TabFragment.greenTea.setText("Solutions");
                        TabFragment.orangePekoe.setText("Solutions");
                        break;
                }
            }

            @Override
            public void onTabUnselected(TabLayout.Tab tab) {
            }

            @Override
            public void onTabReselected(TabLayout.Tab tab) {

            }
        });
    }
}

TabFragment.java

package local.mobileapps.bryandouglas.supremeshoppinglist;

import android.content.SharedPreferences;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import static android.content.Context.MODE_PRIVATE;

public class TabFragment extends Fragment {
    protected static final String ADMIRAL_DOWNSTAIRS_PREFS_NAME = "AdmiralDownstairsPrefsFile";
    protected static final String ADMIRAL_UPSTAIRS_PREFS_NAME = "AdmiralUpstairsPrefsFile";
    protected static final String ADMIRAL_SHIPPING_PREFS_NAME = "AdmiralShippingPrefsFile";
    protected static final String SOLUTIONS_PREFS_NAME = "SolutionsPrefsFile";

    protected static SharedPreferences AdmiralDownstairsData;
    protected static SharedPreferences AdmiralUpstairsData;
    protected static SharedPreferences AdmiralShippingData;
    protected static SharedPreferences SolutionsData;
    protected static SharedPreferences.Editor editor;

    int position;
    protected static TextView cream;
    protected static TextView freshnessBottles;
    protected static TextView soap;
    protected static TextView paperCups;
    protected static TextView shortStirSticks;
    protected static TextView longStirSticks;
    protected static TextView cafeRoyale;
    protected static TextView hotChocolate;
    protected static TextView equal;
    protected static TextView sugar;
    protected static TextView greenTea;
    protected static TextView orangePekoe;

    public static Fragment getInstance(int position) {
        Bundle bundle = new Bundle();
        bundle.putInt("pos", position);
        TabFragment tabFragment = new TabFragment();
        tabFragment.setArguments(bundle);
        return tabFragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        position = getArguments().getInt("pos");
    }

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

    @Override
    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        cream = view.findViewById(R.id.lblCreamValue);
        freshnessBottles = view.findViewById(R.id.lblMilkValue);
        soap = view.findViewById(R.id.lblSoapValue);
        paperCups = view.findViewById(R.id.lblCupValue);
        shortStirSticks = view.findViewById(R.id.lbl4_5StirValue);
        longStirSticks = view.findViewById(R.id.lbl7StirValue);
        cafeRoyale = view.findViewById(R.id.lblCafeRoyaleValue);
        hotChocolate = view.findViewById(R.id.lblHotChocValue);
        equal = view.findViewById(R.id.lblEqualValue);
        sugar = view.findViewById(R.id.lblSugarValue);
        greenTea = view.findViewById(R.id.lblGreenTeaValue);
        orangePekoe = view.findViewById(R.id.lblOrangePekoeValue);
    }
}

ViewPagerAdapter.java

package local.mobileapps.bryandouglas.supremeshoppinglist;

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;

class ViewPagerAdapter extends FragmentPagerAdapter {

    private String title[] = {"Admiral - Downstairs", "Admiral - Upstairs", "Admiral - Shipping", "Solutions"};

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

    @Override
    public Fragment getItem(int position) {
        return TabFragment.getInstance(position);
    }

    @Override
    public int getCount() {
        return title.length;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        return title[position];
    }
}

我试图以一种使用SharedPreferences来存储和读取持久数据的方式来设计它。每个对应的选项卡都有一个特定的sharedPrefs文件。您会注意到sharedPrefs尚未实现，就像我只想使用基本setText进行测试那样。

在运行时更新选项卡片段TextViews

0 个答案: