Android:如何使按钮指向 ListView 项目详细信息(在不同的活动中)(主/详细流程)

Android: How to make a Button Lead to a ListView item details (In differents Activities) (Master / Detail Flow)

我是 Android 开发的初学者。
我知道,这个标题似乎很难理解,但请让我解释一下

我的应用程序是我所在城市的公交线路指南,它包含两个不同的视图:

每个 NavigationDrawer 菜单都指向一个 Activity,其中有几个按钮和公交线路,但只有那些属于 X 区(例如东部)的按钮和公交线路

这里是Activity东的布局:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="10dp"
    android:paddingRight="10dp"
    android:paddingTop="6dp"
    android:paddingBottom="6dp"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:showIn="@layout/activity_leste" tools:context="com.lennoardsilva.teresinabus.Leste">

    <ScrollView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:id="@+id/scrollView2"
        android:layout_alignParentTop="true">

        <LinearLayout
            android:orientation="vertical"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <Button
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:text="@string/l_245"
                android:id="@+id/botao_l_245" />

            <Button
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:text="@string/l_401"
                android:id="@+id/botao_l_401" />

            <Button
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:text="@string/l_402"
                android:id="@+id/botao_l_402" />

            <Button
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:text="@string/l_403"
                android:id="@+id/botao_l_403" />

            <Button
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:text="@string/l_404"
                android:id="@+id/botao_l_404" />

            <Button
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:text="@string/l_405"
                android:id="@+id/botao_l_405" />

            <Button
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:text="@string/l_501"
                android:id="@+id/botao_l_501" />

            <Button
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:text="@string/l_502"
                android:id="@+id/botao_l_502" />

            <Button
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:text="@string/l_503"
                android:id="@+id/botao_l_503" />
            <Button
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:text="@string/l_512"
                android:id="@+id/botao_l_512" />

            <Button
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:text="@string/l_513"
                android:id="@+id/botao_l_513" />

            <Button
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:text="@string/l_518"
                android:id="@+id/botao_l_518" />

            <Button
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:text="@string/l_520"
                android:id="@+id/botao_l_520" />

            <Button
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:text="@string/l_521"
                android:id="@+id/botao_l_521" />

            <Button
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:text="@string/l_522"
                android:id="@+id/botao_l_522" />

            <Button
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:text="@string/l_523"
                android:id="@+id/botao_l_523" />

            <Button
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:text="@string/l_610"
                android:id="@+id/botao_l_610" />
            <Button
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:text="@string/carregar_mais"
                android:id="@+id/botao_carregar_leste"
                android:background="@color/cinza_escuro"
                android:textColor="@color/branco"
                android:textStyle="bold"
                android:onClick="leste_2"
                android:visibility="gone" />

        </LinearLayout>
    </ScrollView>
</RelativeLayout>

<!-- As a told you, a lot of buttons -->

此处 LineListFragment:

package com.lennoardsilva.teresinabus;

import android.app.Activity;
import android.os.Bundle;
import android.support.v4.app.ListFragment;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;

import com.lennoardsilva.teresinabus.dummy.DummyContent;

public class LinhaListFragment extends ListFragment {

    private static final String STATE_ACTIVATED_POSITION = "activated_position";

    private Callbacks mCallbacks = sDummyCallbacks;

    private int mActivatedPosition = ListView.INVALID_POSITION;

    public interface Callbacks {
        public void onItemSelected(String id);
    }

    private static Callbacks sDummyCallbacks = new Callbacks() {
        @Override
        public void onItemSelected(String id) {
        }
    };

    public LinhaListFragment() {
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setListAdapter(new ArrayAdapter<DummyContent.DummyItem>(getActivity(),android.R.layout.simple_list_item_activated_1, android.R.id.text1, DummyContent.ITEMS));
    }

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        if (savedInstanceState != null && savedInstanceState.containsKey(STATE_ACTIVATED_POSITION)) {
            setActivatedPosition(savedInstanceState.getInt(STATE_ACTIVATED_POSITION));
        }
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        // Activities containing this fragment must implement its callbacks.
        if (!(activity instanceof Callbacks)) {
            throw new IllegalStateException("Activity must implement fragment's callbacks.");
        }
        mCallbacks = (Callbacks) activity;
    }

    @Override
    public void onDetach() {
        super.onDetach();
        mCallbacks = sDummyCallbacks;
    }

    @Override
    public void onListItemClick(ListView listView, View view, int position, long id) {
        super.onListItemClick(listView, view, position, id);

        mCallbacks.onItemSelected(DummyContent.ITEMS.get(position).id);
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        if (mActivatedPosition != ListView.INVALID_POSITION) {
            outState.putInt(STATE_ACTIVATED_POSITION, mActivatedPosition);
        }
    }

    public void setActivateOnItemClick(boolean activateOnItemClick) {
        getListView().setChoiceMode(activateOnItemClick ? ListView.CHOICE_MODE_SINGLE : ListView.CHOICE_MODE_NONE);
    }

    private void setActivatedPosition(int position) {
        if (position == ListView.INVALID_POSITION) {
            getListView().setItemChecked(mActivatedPosition, false);
        } else {
            getListView().setItemChecked(position, true);
        }
        mActivatedPosition = position;
    }
}

这里是行列表Activity:

public class LinhaListActivity extends AppCompatActivity
        implements LinhaListFragment.Callbacks {

    private boolean mTwoPane;

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

        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        toolbar.setTitle(getTitle());

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                DialogFragment dialog = new FragmentoDatabase();
                dialog.show(getFragmentManager(), "FragmentoDatabaseTag");

            }
        });
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);

        if (findViewById(R.id.linha_detail_container) != null) {
            mTwoPane = true;
            ((LinhaListFragment) getSupportFragmentManager()
                    .findFragmentById(R.id.linha_list))
                    .setActivateOnItemClick(true);
        }

        // TODO: If exposing deep links into your app, handle intents here.
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        int id = item.getItemId();
        if (id == android.R.id.home) {
            NavUtils.navigateUpFromSameTask(this);
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    @Override
    public void onItemSelected(String id) {
        if (mTwoPane) {
            Bundle arguments = new Bundle();
            arguments.putString(LinhaDetailFragment.ARG_ITEM_ID, id);
            LinhaDetailFragment fragment = new LinhaDetailFragment();
            fragment.setArguments(arguments);
            getSupportFragmentManager().beginTransaction().replace(R.id.linha_detail_container, fragment).commit();

        } else {
            Intent detailIntent = new Intent(this, LinhaDetailActivity.class);
            detailIntent.putExtra(LinhaDetailFragment.ARG_ITEM_ID, id);
            startActivity(detailIntent);
        }
    }
}

此处虚拟内容:

public class DummyContent {

    public static List<DummyItem> ITEMS = new ArrayList<DummyItem>();

    public static Map<String, DummyItem> ITEM_MAP = new HashMap<String, DummyItem>();

    static {
        addItem(new DummyItem("1", "004 - LINE NAME", "Line 004 Details"));
        addItem(new DummyItem("2", "005 - LINE NAME", "Line 005 Details"));
        addItem(new DummyItem("3", "And so on....", "Details"));
        addItem(new DummyItem("100", "100 - LINE NAME", "Line 100 Details"));
      }

    private static void addItem(DummyItem item) {
        ITEMS.add(item);
        ITEM_MAP.put(item.id, item);
    }
    public static class DummyItem {
        public String id;
        public String content;
        public String details;

        public DummyItem(String id, String content, String details) {
            this.id = id;
            this.content = content;
            this.details = details;
        }

        @Override
        public String toString() {
            return content;
        }
    }
}

问题:如何让其中一个按钮启动对应的ItemDetailsActivity ListView?

示例:在 ActivityEast 我有 botao_l_501,在 ListView 它对应于 item 33。 我要botao_l_501开始详细ListView的第33条。 (模板主/详细流程,Google)

你可能想知道的事情:

所以基本上您需要与区域活动(即 ActivityEast)共享 LinhaListFragment 中的适配器信息。问题是在 LinhaListFragment 中你有一个 Adapter 因为你使用的是 ListFragment 但在 ActivityEast 中你有一个 LinearLayout 和一堆Buttons,那么我们如何映射这两个东西一起工作?

第一个解决方案(Hack & Nasty)

在您的 DummyContent class 中,当您添加项目时,还要添加对 Button id 的引用:

static {
    addItem(new DummyItem(R.id.idbotao_l_001, "1", "004 - LINE NAME", "Line 004 Details"));
    addItem(new DummyItem(R.id.idbotao_l_002, "2", "005 - LINE NAME", "Line 005 Details"));
    addItem(new DummyItem(R.id.idbotao_l_033, "33", "033 - LINE NAME", "Details"));
    addItem(new DummyItem(R.id.idbotao_l_100, "100", "100 - LINE NAME", "Line 100 Details"));
  }

然后在每个按钮的 onClick 中你可以做这样的事情:

@Override
public void onClick(View view) {
    for (DummyItem item : DummyContents.ITEMS) {
         if (item.resourceId == view.getId()) {
             //Start the item detail activity
             break;
         }
    }
}

我不知道您是否在使用 DummyContent class 因为您的内容永远不会改变,如果您正在使用它,因为您只是在测试代码。如果将来您要从网络服务中获取该数据,那么此解决方案将毫无用处。

第二种解决方案(干净)

首先,如果你真的想遵循 master/detail 规范,那么你应该只将活动用作片段持有者,因此像 ActivityEast 这样的区域活动不应该存在,你也不应该带有一堆按钮的 LinearLayout。用 ZoneActivity 替换它,其中包含 ZoneFragmentRecyclerView (没有人再使用 ListViewListFragmentRecyclerView 应该设置为启动 ZoneActivity 时在 LinhaListFragment 中使用的 Adapter 要求区域 ID 由 Intent 的捆绑包发送,该 ID 通过ZoneFragment 最后设置为 AdapterAdapter 包含 filter/show 每个区域的行数的逻辑。区域 ID 参数应该不是必需的,因为 ListFragment 它也将使用相同的适配器并且没有区域 ID。

既然您说您刚刚开始 android 开发,那么有一些技巧可以帮助您:

  • 不要使用 ListView 而是使用 RecyclerView

  • 永远不要像在 ActivityEast 中做的那样,如果你要有这么多按钮使用 RecyclerView 即使你的数据是静态的。

  • 没有人再使用 ListFragment 这样的东西了。如果你从类似的东西扩展你附加到那个 class,尝试从你自己的基础 classes 或非常基本的基础 classes 像 Fragment 和 Activity 继承].

  • 尝试使用不分隔代码的区域。例如:

public class MyFragment 扩展片段 {

//region Variables
private int myField;
//endregion

//region Fragment lifecycle
protected void onCreate(Bundle saveInstance) {
 //...
}
//endregion
}

然后您可以折叠它们并以更舒适的方式阅读代码。

  • 永远不要开始 activity 显式,例如:

不好

Intent intent = new Intent(context, MyActivity.class);
intent.putExtra("zoneId",myZoneId);
startActivity(intent);

startActivity(MyActivity.getStartIntent(context, myZoneId));

....
//In MyActivity class
public static getStartIntent(Context context, int zoneId) {
    Intent intent = new Intent(context, MyActivity.class);
    intent.putExtra(MyActiviy.ZONE_ID, zoneId);
    return zoneId;
}

}