Question

您好我是Android的新手。我想实现由项目列表组成的导航抽屉，单击这些项目时会打开一个新活动。基本上是所有活动的导航抽屉。当我从导航栏中选择一个项目时，特定活动会打开，但导航抽屉（汉堡图标）的图标会消失。我怎么做到的？

NavBaseActivity.java

package app.pal.study.samplestudy;

import android.content.Intent;
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.Menu;
import android.view.MenuItem;
import android.widget.FrameLayout;

public class NavBaseActivity extends AppCompatActivity
    implements NavigationView.OnNavigationItemSelectedListener {
private DrawerLayout drawer;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_nav_base);

    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.setDrawerListener(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();
    }
   // getActionBar().setDisplayHomeAsUpEnabled(true);
    //getActionBar().setHomeButtonEnabled(true);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.nav_base, menu);
    return true;
}

@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();


    //noinspection SimplifiableIfStatement
   /* if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);*/
    switch (item.getItemId()) {
        case android.R.id.home:
            drawer.openDrawer(GravityCompat.START);
            return true;
    }

    return super.onOptionsItemSelected(item);
}

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

    if (id == R.id.item_home) {
        // Handle the camera action
        startActivity(new Intent(this, Home.class));

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


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


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


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


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


    }

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    drawer.closeDrawer(GravityCompat.START);
    return true;
}
// `onPostCreate` called when activity start-up is complete after `onStart()`
// NOTE! Make sure to override the method with only a single `Bundle` argument
@Override
protected void onPostCreate(Bundle savedInstanceState) {
    super.onPostCreate(savedInstanceState);
}

}

Syllabus.java

package app.pal.study.samplestudy;

import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.NavigationView;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;

public class Syllabus extends NavBaseActivity implements         NavigationView.OnNavigationItemSelectedListener {

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

}

activity_nav_base.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout   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/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:openDrawer="start">

<include
    layout="@layout/app_bar_nav_base"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

<android.support.design.widget.NavigationView
    android:id="@+id/nav_view"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    android:fitsSystemWindows="true"
    app:headerLayout="@layout/nav_header_nav_base"
    app:menu="@menu/activity_nav_base_drawer" />

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

Answer 1

建议使用带有碎片的导航抽屉，因为它会维护导航抽屉。您必须将您的活动转换为片段。请检查开发人员链接 - http://developer.android.com/training/implementing-navigation/nav-drawer.html

Answer 2

有没有人想出如何让一个主要活动的这个方法推进片段以使用后退按钮？

一切正常“向前”，并且所有片段都被拉入内容框架，但是只要你点击后退按钮，应用程序就会关闭...很可能是因为它是唯一正在运行的活动而后面按钮关闭活动。

无论如何要将代码放入以使片段管理器返回到最后一个片段并且不关闭后退按钮上的活动？

用于多个活动的导航抽屉

2 个答案: