java - 如何使用Android抽屉导航切换回Main Activity

Question

您好，我正在开发一个程序，并使用 Android Studio 为您提供的抽屉导航 Activity 模板制作了一个抽屉导航，这是我的主要 Activity 。我一直在使用 fragment 在应用程序中的页面之间切换，但我认为主 Activity 是抽屉中的选项之一，但我似乎不知道如何使其返回主 Activity。

这是主要的 Activity.java 文件(为了组织而重命名)

package com.eliteapp.eliteapp_indev;

import android.app.FragmentManager;
import android.os.Bundle;
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.MenuItem;

public class your_cmdrs extends AppCompatActivity
        implements NavigationView.OnNavigationItemSelectedListener {

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

        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.addDrawerListener(toggle);
        toggle.syncState();

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

    @Override
    public void onBackPressed() {
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        if (drawer.isDrawerOpen(GravityCompat.START)) {
            drawer.closeDrawer(GravityCompat.START);
        } else {
            super.onBackPressed();
        }
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();


        return super.onOptionsItemSelected(item);
    }

    @SuppressWarnings("StatementWithEmptyBody")
    @Override
    public boolean onNavigationItemSelected(MenuItem item) {
        // Handle navigation view item clicks here.
        int id = item.getItemId();
        switch (id){


        }

        if (id == R.id.GalNet) {
            setTitle("GalNet");
            galnet GalNat = new galnet();
            android.support.v4.app.FragmentManager fragmentManager = getSupportFragmentManager();
            fragmentManager.beginTransaction(). replace(R.id.Your_CMDRS, GalNat).commit();
        } else if (id == R.id.Market) {
            setTitle("Market");
            market Market = new market();
            android.support.v4.app.FragmentManager fragmentManager = getSupportFragmentManager();
            fragmentManager.beginTransaction(). replace(R.id.Your_CMDRS, Market).commit();
        } else if (id == R.id.PowerPlay) {
            setTitle("PowerPlay");
            powrplay PowrPlay = new powrplay();
            android.support.v4.app.FragmentManager fragmentManager = getSupportFragmentManager();
            fragmentManager.beginTransaction(). replace(R.id.Your_CMDRS, PowrPlay).commit();


        } else if (id == R.id.ship_fitting) {
            setTitle("Ship Fitting's");
            ship_fitting Ship_Fitting = new ship_fitting();
            android.support.v4.app.FragmentManager fragmentManager = getSupportFragmentManager();
            fragmentManager.beginTransaction(). replace(R.id.Your_CMDRS, Ship_Fitting).commit();
        } else if (id == R.id.About) {
            setTitle("About");
            about About = new about();
            android.support.v4.app.FragmentManager fragmentManager = getSupportFragmentManager();
            fragmentManager.beginTransaction(). replace(R.id.Your_CMDRS, About).commit();
        } else if (id == R.id.Settings) {
            setTitle("Settings");
            settings Settings = new settings();
            android.support.v4.app.FragmentManager fragmentManager = getSupportFragmentManager();
            fragmentManager.beginTransaction(). replace(R.id.Your_CMDRS, Settings).commit();
        } else if (id == R.id.Change_Log) {
            setTitle("Change Log");
            change_log Chagne_Log = new change_log();
            android.support.v4.app.FragmentManager fragmentManager = getSupportFragmentManager();
            fragmentManager.beginTransaction(). replace(R.id.Your_CMDRS, Chagne_Log).commit();
        }

        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawer.closeDrawer(GravityCompat.START);
        return true;
    }
}

这是 content_Main.xml 文件

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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/Your_CMDRS"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context="com.eliteapp.eliteapp_indev.your_cmdrs"
    tools:showIn="@layout/app_bar_your_cmdrs">

</android.support.constraint.ConstraintLayout>

如果有人能帮助我解决这个问题，那就太好了。

Answer 1

@AJok1776我面临着同样的问题。

解决方案是您创建一个 MainFragment.java 与您的 MainActivity 相同的内容(不包括抽屉导航)默认加载 MainFragment 页面。

MainActivity 内容是唯一的抽屉导航代码。

然后在用户单击主页时在抽屉中添加主页按钮(或其他)，您将重定向 MainFragment 页面。

希望这个解释对你有帮助:)