如何更改主活动中的起始xml

Question

我正试图弄清楚如何在应用程序启动时更改加载的xml。目前它打开activity_main.xml。有没有办法让应用程序打开我的info.xml(也在我的侧导航栏上)而不创建新的活动？

更改了setcontentview的主活动代码：

package com.example.cubehelppp;
import android.os.Bundle;
import androidx.fragment.app.FragmentManager;
import com.google.android.material.navigation.NavigationView;
import androidx.core.view.GravityCompat;
import androidx.drawerlayout.widget.DrawerLayout;
import androidx.appcompat.app.ActionBarDrawerToggle;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
public class MainActivity extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.info);
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 onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, 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);
}
@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
int id = item.getItemId();
FragmentManager fragmentManager = getSupportFragmentManager();
if (id == R.id.nav_first_layout) {
fragmentManager.beginTransaction()
.replace(R.id.content_frame
, new FirstFragment())
.commit();
// Handle the camera action
} else if (id == R.id.nav_second_layout) {
fragmentManager.beginTransaction()
.replace(R.id.content_frame
, new SecondFragment())
.commit();
} else if (id == R.id.nav_third_layout) {
fragmentManager.beginTransaction()
.replace(R.id.content_frame
, new ThirdFragment())
.commit();
}else if (id == R.id.nav_info_layout) {
fragmentManager.beginTransaction()
.replace(R.id.content_frame
, new InfoFragment())
.commit();
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
}

我的info.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal" android:layout_width="match_parent"
android:layout_height="match_parent">

<TextView

android:id="@+id/Info"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:fontFamily="sans-serif-medium"



android:text="@string/welcome_to_app_name"
android:textAlignment="center"
android:textAllCaps="false"
android:textColor="#000000"
android:textSize="30sp" />
<TextView
android:id="@+id/version"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentBottom="true"
android:layout_marginStart="5dp"
android:layout_marginBottom="0dp"
android:fontFamily="sans-serif-light"
android:text="Version 0.1"
android:textAlignment="viewStart"
android:textColor="#000000"
android:textSize="20sp" />

<TextView
android:id="@+id/About"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginStart="5dp"
android:layout_marginTop="40dp"
android:fontFamily="sans-serif-medium"
android:text="CubeHelppp is a cubing application with contains algorithms to 3x3x3. currently OLL, PLL and F2L. In some update soon adding more algorithms to cover wca puzzles! "
android:textColor="#000000"
android:textSize="18sp" />
<TextView
android:id="@+id/patchnotes"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentBottom="true"
android:layout_marginStart="5dp"
android:layout_marginBottom="300dp"
android:fontFamily="sans-serif-medium"
android:text="Patchnotes"
android:textColor="#000000"
android:textSize="24sp" />
<TextView
android:id="@+id/patch1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/patchnotes"
android:layout_alignParentStart="true"
android:layout_marginStart="5dp"
android:layout_marginTop="-300dp"
android:text="-App published with 3x3x3 algorithms"
android:textColor="#000000"
android:textSize="15sp" />
<TextView
android:id="@+id/patch2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/patch1"
android:layout_alignStart="@+id/version"
android:text="-Bugs fixed"
android:textColor="#000000"
android:textSize="15sp" />
</RelativeLayout>

我的activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.drawerlayout.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_main"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<com.google.android.material.navigation.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_main"
app:menu="@menu/activity_main_drawer" />

我的app_bar_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout 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"
tools:context=".MainActivity">
<com.google.android.material.appbar.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="@style/AppTheme.AppBarOverlay">
<androidx.appcompat.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:popupTheme="@style/AppTheme.PopupOverlay" />
</com.google.android.material.appbar.AppBarLayout>
<include
android:id="@+id/include"
layout="@layout/content_main" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>

我在更改setcontentview:时遇到的所有错误

我得到的错误

然后它就崩溃了。我试图创建一个新的活动，但没有让它们发挥作用。

Answer 1

您必须更改AndroidManifest上已启动的活动。像这样：

<activity android:name=".HomePage" />
<activity android:name=".LoginPage">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<action android:name="android.intent.action.VIEW" />    
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>

此登录页是启动应用程序时的第一页。主页是另一项活动。你可以改变它们。