Question

我刚刚开始学习Android / Java，目前正在阅读一本书。我正在进行的活动非常简单，它解释了活动的生命周期，然后解释了如何使用“材质主题”，并说明了如何更改代码来使用它。当我更改代码时（主要添加此"android:theme="@android:style/Theme.Material">"并运行它，我得到：

 "You need to use a Theme.AppCompat theme (or descendant) with this activity."

在AVD屏幕上，我也收到“ Activity101保持停止”的信息。在开始时，我不知道为什么要这样或如何解决它。我正在使用Android Studio 3.2.1和Nexus 5X API 25 AVD。任何帮助都会很棒。

活动

package com.markusmartius.activity101;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
public class MainActivity extends AppCompatActivity
{
    String tag = "Lifecycle Step";
@Override
protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Log.d(tag, "In the onCreate() event");
}
public void onStart()
{
    super.onStart();
    Log.d(tag, "In the onStart() event");
}
public void onRestart()
{
    super.onRestart();
    Log.d(tag, "In the onRestart() event");
}
public void onResume()
{
    super.onResume();
    Log.d(tag, "In the onResume() event");
}
public void onPause()
{
    super.onPause();
    Log.d(tag, "In the onPause() event");
}
public void onStop()
{
    super.onStop();
    Log.d(tag, "In the onStop() event");
}
public void onDestroy()
{
    super.onDestroy();
    Log.d(tag, "In the onDestroy() event");
}
}

清单

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
package="com.markusmartius.activity101">
<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@android:style/Theme.Material">
    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN"/>
            <category android:name="android.intent.category.LAUNCHER"/>
        </intent-filter>
    </activity>
</application>
</manifest>

错误日志（如果需要更多信息，请告诉我）

W/System: ClassLoader referenced unknown path: /data/app    /com.markusmartius.activity101-1/lib/x86
I/InstantRun: starting instant run server: is main process
W/art: Before Android 4.1, method android.graphics.PorterDuffColorFilter      android.support.graphics.drawable.VectorDrawableCompat.updateTintFilter(andro id.graphics.PorterDuffColorFilter, android.content.res.ColorStateList,  android.graphics.PorterDuff$Mode) would have incorrectly overridden the  package-private method in android.graphics.drawable.Drawable
D/AndroidRuntime: Shutting down VM
E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.markusmartius.activity101, PID: 19455
    java.lang.RuntimeException: Unable to start activity   ComponentInfo{com.markusmartius.activity101/com.markusmartius.activity101.Mai nActivity}: java.lang.IllegalStateException: You need to use a   Theme.AppCompat theme (or descendant) with this activity.
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2665)

重大主题错误-您需要在此活动中使用Theme.AppCompat主题（或后代）

0 个答案: