碎片事务无法应用于

Question

大家好，我的碎片有问题。我刚开始开发安卓系统，所以请饶了我。下面是它的内容。

import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;

public class MainActivity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    MyFragment fragment = new MyFragment();
    FragmentManager manager = getFragmentManager();
    FragmentTransaction transaction = manager.beginTransaction();
    transaction.add(R.id.my_layout, fragment, "alvin");
    transaction.commit();
}

我在"transaction.add（）；"部分遇到问题。它说"碎片事务无法应用于。"

我不知道为什么，但这是我的MyFragment.java-

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class MyFragment extends Fragment{
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        return inflater.inflate(R.layout.my_fragment_layout, container, false);
    }
}

和我的activity_main.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:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context=".MainActivity"
    android:background="#00BBFF"
    android:id="@+id/my_layout">

</RelativeLayout>
my_fragment_layout.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"
    android:background="#FFBB00">
    <TextView
        android:layout_margin="40dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:text="MY FRAGMENT"
        android:id="@+id/textView"
        android:layout_gravity="left|center_vertical"/>
    </LinearLayout>

这是我的安卓清单

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

我只想看到我的碎片在我的设备上运行，请提前帮助和感谢。

Answer 1

更换

FragmentManager manager = getFragmentManager();

通过

FragmentManager manager = getSupportFragmentManager();

MyFragment类是一个支持Fragment，您可以通过检查导入语句来看到它

导入android.support.v4.app.Fragment；