嗨，我是 android 新手，我一直在尝试做一个简单的数独应用程序。我现在面临一个问题，每当我单击“关于”按钮时，应用程序往往会停止并带我回到我的菜单屏幕。谁能建议崩溃的问题是什么？
下面是我的代码：
数独.java
public class Sudoku extends Activity implements OnClickListener {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sudoku);
View continueButton=findViewById(R.id.button1);
continueButton.setOnClickListener(this);
View newButton=findViewById(R.id.button2);
newButton.setOnClickListener(this);
View aboutButton=findViewById(R.id.button3);
aboutButton.setOnClickListener(this);
View exitButton=findViewById(R.id.button4);
exitButton.setOnClickListener(this);
}
public void onClick(View v){
switch(v.getId()){
case R.id.button3:
Intent i = new Intent(this, About.class);
startActivity(i);
break;
case R.id.button4:
finish();
break;
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu, menu);
return true;
}
}
关于.java
public class About extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.about);
}
}
关于.xml：
public class About extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.about);
}
}
字符串.xml：
<?xml version="1.0" encoding="utf-8"?>
<string name="app_name">Sudoku</string>
<string name="action_settings">Settings</string>
<string name="hello_world">Application Sudoku</string>
<string name="continue_label">Continue</string>
<string name="new_game_label">New Game</string>
<string name="about_label">About</string>
<string name="exit_label">Exit</string>
<string name="about_title">About Android Sudoku</string>
<string name="about_text">\Sudoku is a logic-based number placement puzzle.
从部分完成的 9x9 网格开始，目标是填充网格，以便每一行、每一列和每个 3x3 框（也称为块）中的数字 1 到 9 恰好包含一次。
activity_sudoku.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:background="@color/background"
tools:context=".Sudoku" >
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/hello_world"
android:textStyle="italic" />
<TableLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:stretchColumns="*">
<TableRow >
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/textView1"
android:layout_below="@+id/textView1"
android:layout_marginTop="22dp"
android:text="@string/continue_label"
android:textStyle="italic"
/>
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/button1"
android:layout_below="@+id/button1"
android:layout_marginTop="21dp"
android:text="@string/new_game_label"
android:textStyle="italic"
/>
</TableRow>
<TableRow >
<Button
android:id="@+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="16dp"
android:text="@string/about_label"
/>
<Button
android:id="@+id/button4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="16dp"
android:text="@string/exit_label"
/>
</TableRow>
</TableLayout>
</RelativeLayout>
数独清单.xml：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="org.example.sudoku"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="org.example.sudoku.Sudoku"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="org.example.sudoku.About"
android:label="@string/about_title"
android:theme="@android:style/Theme.Dialog">
</activity>
</application>
</manifest>