如何使用Android導航抽屜切換回主活動

Question

您好，我正在開發一個程序，並使用Android Studio為您提供的Navigation Drawer Activity模板制作了一個Navigation抽屜，這是我的主要活動。 我一直在使用片段在應用程序中的頁面之間進行切換，但是我將主Activity定義為抽屜中的選項之一，但是似乎無法弄清楚如何使其回到主Activity中。

這是主要的Activity.java文件（為組織重命名）

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;
    }
}

這是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>

如果有人可以幫助我，那就太好了。

Answer 1

@ AJok1776我面臨同樣的問題。

一種解決方案是創建一個與MainActivity相同的MainFragment.java內容（不包括導航抽屜）默認情況下，加載MainFragment頁面。

MainActivity內容是唯一的導航抽屜代碼。

然后，當用戶單擊主頁時，將“主頁”按鈕（或其他按鈕）添加到抽屜中，即可重定向MainFragment頁面。

希望這個解釋對您有幫助:)

Answer 2

編輯：

通過將這段代碼添加到main.java文件中的if語句中，我設法使其正常工作。

} else if (id == R.id.Your_CMDRS) {
            Intent your_cmdrs = new Intent(this, your_cmdrs.class);
            startActivity(your_cmdrs);

現在可以使用了，但是當我切換回活動時會有一個延遲，即使我正在參加主要活動，我什至可以切換到該活動

這是它的視頻： https : //youtu.be/lQ93OeZDxIY

我認為這是事實，這是一項活動，而不是碎片，但我不確定。