从Onclick回调调用启动活动方法后Android应用程序崩溃，清单似乎没问题

Question

我正在编写我的第一个Android应用程序，但我遇到了这个问题：

我想在单击浮动按钮后从主活动切换到添加费用活动，所以我写了这段代码(在protected void onCreate(Bundle savedInstanceState)内(：

FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent intent = new Intent(getApplicationContext(), AddExpense.class);
startActivity(intent);
}
});

AddExpense类看起来很容易像这样

public class AddExpense extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_add_expense);
}

}

但是，在我单击晶圆厂后，应用程序不断崩溃。
浏览其他答案，我发现通常问题出在清单中，但我认为这不是我的情况：

<?xml version="1.0" encoding="utf-8"?>

<application>
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity
android:name=".MainActivity"
android:label="@string/app_name"
android:theme="@style/AppTheme.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".AddExpense"
android:label="@string/app_name"></activity>
</application>

任何帮助将不胜感激。

--编辑-- 日志猫报告：

08-19 18:10:02.802 10393-10393/com.example.senso.budgetracker E/AndroidRuntime: FATAL EXCEPTION: main
      Process: com.example.senso.budgetracker, PID: 10393
      java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.senso.budgetracker/com.example.senso.budgetracker.AddExpense}: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.
          at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2728)
          at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2814)
          at android.app.ActivityThread.-wrap12(ActivityThread.java)
          at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1527)
          at android.os.Handler.dispatchMessage(Handler.java:102)
          at android.os.Looper.loop(Looper.java:154)
          at android.app.ActivityThread.main(ActivityThread.java:6290)
          at java.lang.reflect.Method.invoke(Native Method)
          at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
       Caused by: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.
          at android.support.v7.app.AppCompatDelegateImplV9.createSubDecor(AppCompatDelegateImplV9.java:356)
          at android.support.v7.app.AppCompatDelegateImplV9.ensureSubDecor(AppCompatDelegateImplV9.java:325)
          at android.support.v7.app.AppCompatDelegateImplV9.setContentView(AppCompatDelegateImplV9.java:286)
          at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:139)
          at com.example.senso.budgetracker.AddExpense.onCreate(AddExpense.java:11)
          at android.app.Activity.performCreate(Activity.java:6760)
          at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1134)
          at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2681)
          at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2814) 
          at android.app.ActivityThread.-wrap12(ActivityThread.java) 
          at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1527) 
          at android.os.Handler.dispatchMessage(Handler.java:102) 
          at android.os.Looper.loop(Looper.java:154) 
          at android.app.ActivityThread.main(ActivityThread.java:6290) 
          at java.lang.reflect.Method.invoke(Native Method) 

Answer 1

在您的 XML 中尝试添加这样的主题标签：

<activity android:name=".AddExpense"
android:label="@string/app_name"
android:parentActivityName=".MainActivity"
android:theme="@style/AppTheme.NoActionBar">
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="blah.blah.com.Myproject.MainActivity" // your package replace
/>
</activity>

Answer 2

我发现，这是一个语法问题！
不知何故，编辑清单，我改变了

<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">

在

<application>
android:allowBackup="true" 
...
android:theme="@style/AppTheme">

立即关闭应用程序标记，并使属性不可解析。
正确关闭标签足以使一切正常。