我有一个有2个按钮的活动。我的活动中的片段会在按钮点击时更改。但我面临的问题是 - activity_main.xml。
以下是我的代码 -
<LinearLayout 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:orientation="vertical"
tools:context=".MainActivity">
<Button
android:id="@+id/button1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:onClick="selectFrag"
android:text="Select Fragment 1" />
<Button
android:id="@+id/button2"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:onClick="selectFrag"
android:text="Select Fragment 2" />
<fragment
android:id="@+id/fragment_place"
android:name="com.example.rahul.fragmentdemo.FragmentOne"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:layout="@layout/fragment_one" />
</LinearLayout>
MainActivity.javapackage com.example.rahul.fragmentdemo;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
public class MainActivity extends FragmentActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void selectFrag(View view) {
Fragment fr = null;
if (view == findViewById(R.id.button2)) {
fr = new FragmentTwo();
} else {
fr = new FragmentOne();
}
FragmentManager fm = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fm.beginTransaction();
fragmentTransaction.replace(R.id.fragment_place, fr);
fragmentTransaction.commit();
}
}
FragmentOne.javapackage com.example.rahul.fragmentdemo;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class FragmentOne extends Fragment {
public FragmentOne() {
// Required empty public constructor
}
@Override
public void onCreate(Bundle savedInstanceState) {
Log.i("Fragment Demo", "Fragment_One onCreate()");
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_one, container, false);
return view;
}
}
fragment_one.xml <FrameLayout 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" tools:context="com.example.rahul.fragmentdemo.FragmentOne">
<!-- TODO: Update blank fragment layout -->
<TextView
android:id="@+id/tvFragment_1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="This is Fragment 1" />
</FrameLayout>
FragmentOne.java与fragment_two.xml和FragmentTwo.java类似，我的代码分别有fragment_two.xml和java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.rahul.fragmentdemo/com.example.rahul.fragmentdemo.MainActivity}: android.view.InflateException: Binary XML file line #24: Error inflating class fragment
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
at android.app.ActivityThread.access$800(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: android.view.InflateException: Binary XML file line #24: Error inflating class fragment
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:763)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:806)
at android.view.LayoutInflater.inflate(LayoutInflater.java:504)
at android.view.LayoutInflater.inflate(LayoutInflater.java:414)
at android.view.LayoutInflater.inflate(LayoutInflater.java:365)
at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:377)
at android.app.Activity.setContentView(Activity.java:2144)
at com.example.rahul.fragmentdemo.MainActivity.onCreate(MainActivity.java:18)
at android.app.Activity.performCreate(Activity.java:5937)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
at android.app.ActivityThread.access$800(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: android.support.v4.app.SuperNotCalledException: Fragment FragmentOne{3fdec5ae #0 id=0x7f0c0051} did not call through to super.onCreate()
at android.support.v4.app.Fragment.performCreate(Fragment.java:1768)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:917)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1116)
at android.support.v4.app.FragmentManagerImpl.addFragment(FragmentManager.java:1218)
at android.support.v4.app.FragmentManagerImpl.onCreateView(FragmentManager.java:2170)
at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:300)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:727)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:806)
at android.view.LayoutInflater.inflate(LayoutInflater.java:504)
at android.view.LayoutInflater.inflate(LayoutInflater.java:414)
at android.view.LayoutInflater.inflate(LayoutInflater.java:365)
at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:377)
at android.app.Activity.setContentView(Activity.java:2144)
at com.example.rahul.fragmentdemo.MainActivity.onCreate(MainActivity.java:18)
at android.app.Activity.performCreate(Activity.java:5937)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
at android.app.ActivityThread.access$800(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
。
我得到例外 -
MainActivity.java:18 - setContentView(R.layout.activity_main);
指的是
{{1}}
答案 0 :(得分：1)
正如错误日志所述，a = 'cat'
@a = 'dog'
a #=> "cat"
a = 'pig'
@a #=> "dog"
中缺少super.onCreate：
FragmentOne.java