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我看着从这个家伙的教程：
https://www.youtube.com/watch?v=-SUvA1fXaKw错误：无法找到符号变量
末（约9:55），他写下：
if(fragment != null) {
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.replace(R.id.content_main, fragment);
ft.commit();
我重新命名content_main在activity_main_menu1_start_seite我认为我可以用activity_main_menu1_start_seite替换content_main，但它会说“找不到符号变量activity_main_menu1_start_seite”
也许你需要我的整个Co德。
我把你的错误标记为Blockquote。
对不起任何问题（我是新来这个网站）
package com.d_and_d_studios.test3;
import android.Manifest;
import android.app.Fragment;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.Color;
import android.os.Bundle;
import android.support.design.widget.NavigationView;
import android.support.v4.app.FragmentTransaction;
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.view.View;
import android.widget.TextView;
import android.widget.Toast;
import at.markushi.ui.CircleButton;
public class MainActivity extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener {
CircleButton btn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main_drawer);
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);
btn = (CircleButton) findViewById(R.id.circleButton);
}
@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;
}
//Brauche ich vielleicht doch noch irgendwann!
//@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);
//}
private void displaySelectedScreen(int id) {
Fragment fragment = null;
switch (id) {
case R.id.nav_powersavingmode:
fragment = new Menu_2_Energiesparmodus();
break;
case R.id.nav_feedback:
fragment = new Menu_3_Bewerte_die_App();
break;
case R.id.nav_send:
fragment = new Menu_4_Teile_uns_Fehler_mit();
}
if(fragment != null) { FragmentTransaction ft = getSupportFragmentManager().beginTransaction(); ft.replace(R.id.activity_main_menu1_start_seite, fragment); ft.commit(); }
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
}
@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
int id = item.getItemId();
if (id == R.id.nav_powersavingmode) {
// Handle the camera action
} else if (id == R.id.nav_feedback) {
} else if (id == R.id.nav_send) {
}
displaySelectedScreen(id);
return true;
}
}
<?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:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/backgroundcolor"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="com.d_and_d_studios.test3.MainActivity"
tools:showIn="@layout/toolbar_main">
<at.markushi.ui.CircleButton
android:id="@+id/circleButton"
android:layout_width="116dp"
android:layout_height="116dp"
android:layout_centerInParent="true"
android:src="@drawable/ic_power_settings_new_black_24dp"
app:cb_color="#000"
app:cb_pressedRingWidth="20dp"
tools:layout_editor_absoluteY="178dp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/menu1_text1"
android:fontFamily="sans-serif"
android:textColor="@color/colorPrimary"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintVertical_bias="0.23" />
</android.support.constraint.ConstraintLayout>
您是否也可以发布您的XML文件？ –
确定如果我知道如何......代码长 –
代码的长度并不重要，只需复制整个代码并将其粘贴到此处就像发布您的Java类一样。编辑你的问题并粘贴XML文件的代码。 –