Question

当我在我的应用上按登录时，它应该会带我到 activity.targa，但它崩溃了，我不明白为什么（我的手机是 Redmi Note 7，但它也在 Mi A2 上崩溃）

>

activity.targa：

<?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:background="#FFFFFF"
android:fitsSystemWindows="true"
tools:context=".TargaActivity">

<LinearLayout
    android:id="@+id/linearLayout2"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent">

    <androidx.appcompat.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="@color/colorPrimary"
        android:elevation="4dp"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
        app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />

    <com.google.android.material.circularreveal.CircularRevealFrameLayout
        android:id="@+id/fragment_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <TextView.../>

    <com.google.android.material.textfield.TextInputLayout.../>

    <TextView.../>

    <TextView.../>

</LinearLayout>

<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"
    app:headerLayout="@layout/nav_header"
    app:menu="@menu/drawer_menu" />

</androidx.drawerlayout.widget.DrawerLayout>

和 TargaActivity：

package com.efficientparking.efficientparking;

import android.os.Bundle;
import android.widget.TextView;
import androidx.appcompat.app.ActionBarDrawerToggle;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.view.GravityCompat;
import androidx.drawerlayout.widget.DrawerLayout;
import java.util.HashMap;

public class TargaActivity extends AppCompatActivity {

private DrawerLayout drawer;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_targa);
    androidx.appcompat.widget.Toolbar toolbar = findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    drawer = 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();
}

@Override
public void onBackPressed() {
    if(drawer.isDrawerOpen(GravityCompat.START)){
        drawer.closeDrawer(GravityCompat.START);
    } else {
        super.onBackPressed();
    }
}

}

androidx.appcompat.widget.Toolbar toolbar = findViewById(R.id.toolbar); 我不得不在这里更改，因为 Android Studio 给我带来了麻烦，因为他说以下方法 (setSupportActionBar(toolbar)) 不存在。

但是现在，只要我尝试进入 activity_targa，应用就会崩溃。

Android studio 实际上加载了 xml，看起来不错，但是我编译了 apk 后它崩溃了。

日志文件：

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.efficientparking/com.efficientparking.efficientparking.TargaActivity}: java.lang.ClassCastException: android.widget.Toolbar cannot be cast to androidx.appcompat.widget.Toolbar
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3311)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3460)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2047)
at android.os.Handler.dispatchMessage(Handler.java:107)
at android.os.Looper.loop(Looper.java:224)
at android.app.ActivityThread.main(ActivityThread.java:7590)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:539)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:950)
Caused by: java.lang.ClassCastException: android.widget.Toolbar cannot be cast to androidx.appcompat.widget.Toolbar
at com.efficientparking.efficientparking.TargaActivity.onCreate(TargaActivity.java:22)
at android.app.Activity.performCreate(Activity.java:7893)
at android.app.Activity.performCreate(Activity.java:7880)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1307)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3286)
... 11 more

Answer 1

您应该在 android.widget.Toolbar 和 xml 中使用 java，因为 setSupportActionBar 需要 android.widget.Toolbar

当我尝试打开活动时应用程序崩溃

1 个答案: