Question

我正在尝试使用片段更改content_navegacao.xml的内容，但提交似乎无效。

我创建了一个带有空活动布局的项目，之后我创建了一个导航抽屉活动，并且我试图在导航抽屉布局中更改我的片段的内容。我的事务在Navigation_Drawer活动中进行管理。我想，也许在这种情况下使用的进口可能是对此负责，因为导航抽屉布局扩展了AppCompactAcivity类。

我做了类似的事情：

在content_navegacao中创建片段：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context="receitas.cleiton.com.br.receitas.Navegacao_Activity"
    tools:showIn="@layout/app_bar_navegacao_">


    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/container_conteudo">


    </LinearLayout>
</RelativeLayout>

创建片段布局 - ＆gt; fragment_home.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#ff0000">

</LinearLayout>

创建片段类

package receitas.cleiton.com.br.receitas;

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;

public class Home_Fragment extends Fragment {

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_home,null);
        return view;
    }
}

最后，我在NavigationDrawerAcitvity类上进行了最后的实现：

活动变得像：

package receitas.cleiton.com.br.receitas;

import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.view.View;
import android.support.design.widget.NavigationView;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;

public class Navegacao_Activity extends AppCompatActivity
        implements NavigationView.OnNavigationItemSelectedListener {

    FragmentManager fm = getSupportFragmentManager();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_navegacao_);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });

        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
                this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
        drawer.setDrawerListener(toggle);
        toggle.syncState();

        NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
        navigationView.setNavigationItemSelectedListener(this);

        if(savedInstanceState == null){
            Home_Fragment home_fragment = new Home_Fragment();
            FragmentTransaction fragmentTransaction = fm.beginTransaction();
            fragmentTransaction.add(R.id.container_conteudo,home_fragment,"home");
            fragmentTransaction.addToBackStack("stack");
            fragmentTransaction.commit();
        }
    }

但......当活动加载时，没有任何反应。

任何想法？

Answer 1

在没有局部变量的if(savedInstanceState == null){之后尝试。

getSupportFragmentManager().beginTransaction().replace(fragment, R.id.container, "home").addToBackStack("tag").commit();

P.S.I不建议在公告后立即初始化变量。在onCreate（）方法中执行;

为什么framentTransaction.commit不起作用？

1 个答案: