無法將協調器布局強制轉換為android.support.v7.widget.Toolbar錯誤導致應用崩潰

Question

我正在嘗試構建導航抽屜活動，並且每當要顯示主要活動時都會出現此錯誤，並使應用程序崩潰。

xml代碼：

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.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">

<android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/AppTheme.AppBarOverlay">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:background="?attr/colorPrimaryDark"
        app:popupTheme="@style/AppTheme.PopupOverlay" />

</android.support.design.widget.AppBarLayout>

<include layout="@layout/content_main" />

<android.support.design.widget.FloatingActionButton
    android:id="@+id/Button_sign_out"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentRight="true"
    android:layout_alignParentBottom="true"
    android:layout_gravity="bottom|end"
    android:layout_margin="@dimen/fab_margin"
    android:src="@drawable/ic_arrow_forward_black_24dp"
    />

</android.support.design.widget.CoordinatorLayout>

這是我的Java代碼：

package com.android.example.ithelpdesk;

import android.content.Intent;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
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.view.View;
import android.widget.AdapterView;
import android.widget.ListView;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity
    implements NavigationView.OnNavigationItemSelectedListener {

public DrawerLayout drawer;
public Toolbar supportActionBar;
private boolean mToolBarNavigationListenerIsRegistered  = false;
ActionBarDrawerToggle toggle;

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

    populateTicketList();

   Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    getSupportActionBar().setDisplayShowTitleEnabled(false);
    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);
    drawer.setDrawerListener(toggle);
    toggle.syncState();

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

    ListView listView = (ListView) findViewById(R.id.lvSubcategory);
    listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {

  @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int 
       i, long l) {
       Intent intent = new Intent(MainActivity.this, ComplaintDetail.class);
                startActivity(intent);
        }
    });

}

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

/*private void signOut() {
    mGoogleSignInClient.signOut()
            .addOnCompleteListener(this, new OnCompleteListener<Void>() {
                @Override
                public void onComplete(@NonNull Task<Void> task) {
                    // ...
                }
            });
}*/

@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);
}

public void setSupportActionBar(Toolbar supportActionBar) {
    this.supportActionBar = supportActionBar;
}


private void populateTicketList() {
    ArrayList<Ticket> arrayOfTicket = Ticket.getTicket();

    TicketAdapter adapter = new TicketAdapter(this, arrayOfTicket);
    ListView listView = (ListView) findViewById(R.id.lvTicket);
    listView.setAdapter(adapter);

}

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

    if (id == R.id.nav_complaint) {
        Intent intent = new Intent(MainActivity.this, TicketCategory.class);
        startActivity(intent);
    }
    else if (id == R.id.nav_profile) {
        Intent intent = new Intent(this, MainActivity.class);
        startActivity(intent);
    }// else if (id == R.id.nav_slideshow) {

     //  } else if (id == R.id.nav_manage) {

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

}

日志貓的崩潰：

請幫助。 我是一個初學者，所以我希望對這個問題做出解釋，以解決問題是什么以及將來如何避免該問題。

這是logcat：

java.lang.RuntimeException：無法啟動活動ComponentInfo {com.android.example.ithelpdesk / com.android.example.ithelpdesk.MainActivity}：java.lang.ClassCastException：android.support.design.widget.CoordinatorLayout無法轉換為android.app.ActivityThread.performLaunchActivity（ActivityThread.java:2455）上的android.support.v7.widget.Toolbar android.app.ActivityThread.access $ 1000（ActivityThread）上android.app.ActivityThread.handleLaunchActivity（ActivityThread.java:2515）上的android.support.v7.widget.Toolbar .java：154）android.app.ActivityThread $ H.handleMessage（ActivityThread.java:1379）android.os.Handler.dispatchMessage（Handler.java:102）android.os.Looper.loop（Looper.java： 157），位於android.app.ActivityThread.main（ActivityThread.java:5571），位於com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java：的java.lang.reflect.Method.invoke（本機方法）處）： 745）at com.android.internal.os.ZygoteInit.main（ZygoteInit.java:635）原因：java.lang.ClassCastException：android.support.design.widget.Coor dinatorLayout無法在android.app.Activity.performCreate（Activity.java:6357）在com.android.example.ithelpdesk.Mainhelpity.onCreate（MainActivity.java:35）在android.app.Activity.performCreate（Activity.java:6357）上投放到android.support.v7.widget.Toolbar .app.Instrumentation.callActivityOnCreate（Instrumentation.java:1108）位於android.app.ActivityThread.performLaunchActivity（ActivityThread.java:2408）...還有9個

Answer 1

您尚未在xml代碼中實現DrawerLayout和NavigationView Layout。 如果您不知道此布局，請嘗試以下鏈接

如何在Android中創建自定義導航抽屜