我是编程方面的新手，可能有一个简单的问题： 我有一个按钮，当它被点击时，一个新的活动将开始。 Android Studio没有发现任何错误，但是当我启动应用程序时，它会立即崩溃... 这是我的代码
头部活动java：
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import java.lang.String;
public class head_screen extends AppCompatActivity {
String titletext = "Try Your Math!";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_head_screen);
}
public void start (View view){
Button btnstart = (Button) findViewById(R.id.btnStart);
btnstart.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent start = new Intent(head_screen.this, Aufgabe1.class);
startActivity(start);
}
});
}
}
头部活动xml：
<?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="#8B5A2B"
tools:context="com.example.samuel.try_your_math.head_screen"
>
<Button
android:id="@+id/btnStart"
style="@style/Widget.AppCompat.Button"
android:layout_width="136dp"
android:layout_height="78dp"
android:background="#0F0F0F"
android:onClick="start"
android:text="Play"
android:textAllCaps="true"
android:textAppearance="@style/TextAppearance.AppCompat"
android:textColor="@android:color/background_light"
android:textSize="30sp"
android:textStyle="bold|italic"
tools:layout_editor_absoluteX="124dp"
tools:layout_editor_absoluteY="244dp"
tools:text="Play" />
</android.support.constraint.ConstraintLayout>
第二个活动java：
import android.app.Activity;
import android.os.Bundle;
public class Aufgabe1 extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.aufgabe1);
}
}
第二个活动xml：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/textView2"
android:layout_width="match_parent"
android:layout_height="50dp"
android:text="Did it"
android:layout_marginTop="200dp"
android:textSize="50dp"/>
</LinearLayout>
清单：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.samuel.try_your_math">
<application
android:allowBackup="true"
android:theme="@android:style/Theme.NoTitleBar"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true">
<activity android:name=".head_screen">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
styles.xml：
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat">
<!-- Customize your theme here. -->
<item name="colorPrimary">@color/colorPrimary</item>
<item name="colorPrimaryDark">@color/colorPrimaryDark</item>
<item name="colorAccent">@color/colorAccent</item>
</style>
</resources>
启动应用时，控制台中会显示以下错误代码：
03-31 16:09:49.188 11770-11770/? D/dalvikvm: Late-enabling CheckJNI
03-31 16:09:49.288 11770-11770/com.example.samuel.try_your_math I/dalvikvm: Could not find method android.view.Window$Callback.onProvideKeyboardShortcuts, referenced from method android.support.v7.view.WindowCallbackWrapper.onProvideKeyboardShortcuts
03-31 16:09:49.288 11770-11770/com.example.samuel.try_your_math W/dalvikvm: VFY: unable to resolve interface method 16999: Landroid/view/Window$Callback;.onProvideKeyboardShortcuts (Ljava/util/List;Landroid/view/Menu;I)V
03-31 16:09:49.288 11770-11770/com.example.samuel.try_your_math D/dalvikvm: VFY: replacing opcode 0x72 at 0x0002
03-31 16:09:49.298 11770-11770/com.example.samuel.try_your_math W/dalvikvm: VFY: unable to find class referenced in signature (Landroid/view/SearchEvent;)
03-31 16:09:49.298 11770-11770/com.example.samuel.try_your_math I/dalvikvm: Could not find method android.view.Window$Callback.onSearchRequested, referenced from method android.support.v7.view.WindowCallbackWrapper.onSearchRequested
03-31 16:09:49.298 11770-11770/com.example.samuel.try_your_math W/dalvikvm: VFY: unable to resolve interface method 17001: Landroid/view/Window$Callback;.onSearchRequested (Landroid/view/SearchEvent;)Z
03-31 16:09:49.298 11770-11770/com.example.samuel.try_your_math D/dalvikvm: VFY: replacing opcode 0x72 at 0x0002
03-31 16:09:49.298 11770-11770/com.example.samuel.try_your_math I/dalvikvm: Could not find method android.view.Window$Callback.onWindowStartingActionMode, referenced from method android.support.v7.view.WindowCallbackWrapper.onWindowStartingActionMode
03-31 16:09:49.298 11770-11770/com.example.samuel.try_your_math W/dalvikvm: VFY: unable to resolve interface method 17005: Landroid/view/Window$Callback;.onWindowStartingActionMode (Landroid/view/ActionMode$Callback;I)Landroid/view/ActionMode;
03-31 16:09:49.298 11770-11770/com.example.samuel.try_your_math D/dalvikvm: VFY: replacing opcode 0x72 at 0x0002
03-31 16:09:49.298 11770-11770/com.example.samuel.try_your_math I/dalvikvm: Could not find method android.content.res.TypedArray.getChangingConfigurations, referenced from method android.support.v7.widget.TintTypedArray.getChangingConfigurations
03-31 16:09:49.298 11770-11770/com.example.samuel.try_your_math W/dalvikvm: VFY: unable to resolve virtual method 462: Landroid/content/res/TypedArray;.getChangingConfigurations ()I
03-31 16:09:49.298 11770-11770/com.example.samuel.try_your_math D/dalvikvm: VFY: replacing opcode 0x6e at 0x0002
03-31 16:09:49.298 11770-11770/com.example.samuel.try_your_math I/dalvikvm: Could not find method android.content.res.TypedArray.getType, referenced from method android.support.v7.widget.TintTypedArray.getType
03-31 16:09:49.298 11770-11770/com.example.samuel.try_your_math W/dalvikvm: VFY: unable to resolve virtual method 484: Landroid/content/res/TypedArray;.getType (I)I
03-31 16:09:49.298 11770-11770/com.example.samuel.try_your_math D/dalvikvm: VFY: replacing opcode 0x6e at 0x0008
03-31 16:09:49.318 11770-11770/com.example.samuel.try_your_math D/AndroidRuntime: Shutting down VM
03-31 16:09:49.318 11770-11770/com.example.samuel.try_your_math W/dalvikvm: threadid=1: thread exiting with uncaught exception (group=0x416fad88)
03-31 16:09:49.318 11770-11770/com.example.samuel.try_your_math E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.samuel.try_your_math, PID: 11770
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.samuel.try_your_math/com.example.samuel.try_your_math.head_screen}: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2252)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2301)
at android.app.ActivityThread.access$800(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1246)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5212)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:602)
at dalvik.system.NativeStart.main(Native Method)
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:359)
at android.support.v7.app.AppCompatDelegateImplV9.ensureSubDecor(AppCompatDelegateImplV9.java:328)
at android.support.v7.app.AppCompatDelegateImplV9.setContentView(AppCompatDelegateImplV9.java:289)
at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:140)
at com.example.samuel.try_your_math.head_screen.onCreate(head_screen.java:18)
at android.app.Activity.performCreate(Activity.java:5240)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1088)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2216)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2301)
at android.app.ActivityThread.access$800(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1246)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5212)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:602)
at dalvik.system.NativeStart.main(Native Method)
03-31 16:09:51.438 11770-11770/? I/Process: Sending signal. PID: 11770 SIG: 9
非常感谢，我希望你能帮助我， 最好的祝福， SAMU