第一个布局可以是片段吗？

Question

我有带片段的Navigator Drawer，但第一个布局是main_activity，刚启动应用程序后就是posible call片段。

public class MainActivity extends AppCompatActivity {

private Toolbar toolbar;
private ScrimInsetsFrameLayout sifl;
private DrawerLayout drawerLayout;
private ActionBarDrawerToggle drawerToggle;
private ListView ndList;
/**
 * ATTENTION: This was auto-generated to implement the App Indexing API.
 * See https://g.co/AppIndexing/AndroidStudio for more information.
 */
private GoogleApiClient client;

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

    sifl = (ScrimInsetsFrameLayout) findViewById(R.id.scrimInsetsFrameLayout);

    //Toolbar

    toolbar = (Toolbar) findViewById(R.id.appbar);
    setSupportActionBar(toolbar);

    //Menu del Navigation Drawer

    ndList = (ListView) findViewById(R.id.navdrawerlist);

    final String[] opciones = new String[]{"Lunes", "Martes", "Miercoles", };

    ArrayAdapter<String> ndMenuAdapter =
            new ArrayAdapter<>(this,
                    android.R.layout.simple_list_item_activated_1, opciones);

    ndList.setAdapter(ndMenuAdapter);

    ndList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @override
        public void onItemClick(AdapterView<?> adapterView, View view, int pos, long l) {
            Fragment fragment = null;

            switch (pos) {
                case 0:
                    fragment = new Fragment1();
                    break;
                case 1:
                    fragment = new Fragment2();
                    break;
                case 2:
                    fragment = new Fragment3();
                    break;



            }

            getSupportFragmentManager().beginTransaction()
                    .replace(R.id.content_frame, fragment)
                    .commit();

            ndList.setItemChecked(pos, true);

            getSupportActionBar().setTitle(opciones[pos]);

            drawerLayout.closeDrawer(sifl);
        }
    });

    //Drawer Layout

    drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
    drawerLayout.setStatusBarBackgroundColor(getResources().getColor(R.color.colorPrimaryDark));

    drawerToggle = new ActionBarDrawerToggle(
            this, drawerLayout, R.string.openDrawer, R.string.closeDrawer) {

        @override
        public void onDrawerOpened(View drawerView) {
            super.onDrawerOpened(drawerView);
        }

        @override
        public void onDrawerClosed(View drawerView) {
            super.onDrawerClosed(drawerView);
        }
    };

    drawerLayout.setDrawerListener(drawerToggle);

    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    getSupportActionBar().setHomeButtonEnabled(true);

    // ATTENTION: This was auto-generated to implement the App Indexing API.
    // See https://g.co/AppIndexing/AndroidStudio for more information.
    client = new GoogleApiClient.Builder(this).addApi(AppIndex.API).build();
}


@override
public boolean onOptionsItemSelected(MenuItem item) {

    if (drawerToggle.onOptionsItemSelected(item)) {
        return true;
    }
    return false;
}

@override
protected void onPostCreate(Bundle savedInstanceState) {
    super.onPostCreate(savedInstanceState);
    drawerToggle.syncState();
}

@override
public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged(newConfig);
    drawerToggle.onConfigurationChanged(newConfig);
}

@override
public void onStart() {
    super.onStart();

    // ATTENTION: This was auto-generated to implement the App Indexing API.
    // See https://g.co/AppIndexing/AndroidStudio for more information.
    client.connect();
    Action viewAction = Action.newAction(
            Action.TYPE_VIEW, // TODO: choose an action type.
            "Main Page", // TODO: Define a title for the content shown.
            // TODO: If you have web page content that matches this app activity's content,
            // make sure this auto-generated web page URL is correct.
            // Otherwise, set the URL to null.
            Uri.parse("http://host/path               // TODO: Make sure this auto-generated app deep link URI is correct.
            Uri.parse("android-app://com.arisguimera.calisthenicsroutine/http/host/path      );
    AppIndex.AppIndexApi.start(client, viewAction);
}

@override
public void onStop() {
    super.onStop();

    // ATTENTION: This was auto-generated to implement the App Indexing API.
    // See https://g.co/AppIndexing/AndroidStudio for more information.
    Action viewAction = Action.newAction(
            Action.TYPE_VIEW, // TODO: choose an action type.
            "Main Page", // TODO: Define a title for the content shown.
            // TODO: If you have web page content that matches this app activity's content,
            // make sure this auto-generated web page URL is correct.
            // Otherwise, set the URL to null.
            Uri.parse("http://host/path               // TODO: Make sure this auto-generated app deep link URI is correct.
            Uri.parse("android-app://com.arisguimera.calisthenicsroutine/http/host/path      );
    AppIndex.AppIndexApi.end(client, viewAction);
    client.disconnect();
 }
}

我的问题是我可以在启动应用程序后调用片段。 我认为这样的事情，但不是工作。

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

例如，为我的fragment_fragment1更改R.layout.activity_main

主要活动：

<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true">



<!-- Contenido de la actividad -->
<include layout="@layout/content_layout" />

<!-- Navigation Drawer Layout -->
<include layout="@layout/navdrawer_layout" />



</android.support.v4.widget.DrawerLayout>

conten_layout：

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">



<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:clickable="true"
tools:context=".MainActivity"
tools:showIn="@layout/activity_main">




 <!-- Toolbar -->
  <android.support.v7.widget.Toolbar xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/appbar"
    android:layout_height="?attr/actionBarSize"
    android:layout_width="match_parent"
    android:minHeight="?attr/actionBarSize"
    android:background="?attr/colorPrimary"
    android:elevation="4dp"
    android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
    app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />

<!-- Resto de la interfaz de usuario -->
<FrameLayout
    android:id="@+id/content_frame"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >



</FrameLayout>

</LinearLayout>

</RelativeLayout>

Nav_drawer：

<?xml version="1.0" encoding="utf-8"?>

<com.arisguimera.calisthenicsroutine.ScrimInsetsFrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/scrimInsetsFrameLayout"
android:layout_width="300dp"
android:layout_height="match_parent"
android:layout_gravity="start"
android:background="@android:color/white"
android:elevation="10dp"
android:fitsSystemWindows="true"
app:insetForeground="#4000"
tools:showIn="@layout/activity_main">

 <LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_gravity="left|start"
    android:background="@android:color/white"
    android:orientation="vertical">

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="200dp"
        android:src="@drawable/clogo"
        android:scaleType="centerCrop" />

    <ListView
        android:id="@+id/navdrawerlist"
        android:layout_height="match_parent"
        android:layout_width="match_parent"
        android:divider="@null"
        android:choiceMode="singleChoice" />

</LinearLayout>

</com.arisguimera.calisthenicsroutine.ScrimInsetsFrameLayout>

Answer 1

好吧，要查看片段，您需要一个FragmentManager，这意味着您的Activity需要扩展ActivityFragment。 （我不确定AppCombatActivity是否这样做）通过代码的外观，你似乎已经知道了。

最终，你不能这样做，因为片段被一个名为onCreateView的Fragment类方法放在屏幕上，而不是Oncreate 。 活动意味着不要托管碎片，不要直接膨胀碎片。

Answer 2

对于片段是活着的，它应该绑定到一个活动。 因为它需要上下文来继承它的一些用法。

这实际上取决于你作为片段理解的内容。

但是让我直截了当地说：是的，你的第一个布局肯定是一个片段。 但是如何？！

您的第一个活动的XML可能有一个占位符，您的片段可以在其中充气。 片段有一个名为“replace”的方法，它将给定片段膨胀为xml占位符。 你只需要为它放一个R.id。

举个例子：

// Create new fragment and transaction
Fragment newFragment = new ExampleFragment();
FragmentTransaction transaction = getFragmentManager().beginTransaction();

// Replace whatever is in the fragment_container view with this fragment,
// and add the transaction to the back stack
transaction.replace(R.id.fragment_container, newFragment);
transaction.addToBackStack(null);

// Commit the transaction
transaction.commit();