Android 什么是ActionBar.setHomeButtonEnabled（布尔值）

我想创建一个包含2个选项卡的viewpager，我有3个布局：

这是activity_chart.xml，包含以下文件：

<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/pager"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
</android.support.v4.view.ViewPager>

这是TabsPagerAdapter.java类：

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;


/**
 * Created by Salar on 26/4/2015.
 */
public class TabsPagerAdapter extends FragmentPagerAdapter {
    public TabsPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int index) {

        switch (index) {
            case 0:
                // Accounts Activity fragment activity
                return new AccountsActivityFragment();
            case 1:
                // Chart Activity activity
                return new ChartActivityFragment();
        }
        return null;
    }

    @Override
    public int getCount() {
        // get item count - equal to number of tabs
        return 2;
    }

}

这是AccountsActivityFragment.java：

import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.rastari.salar.mymetarialbank.R;

/**
 * Created by Salar on 25/4/2015.
 */
public class AccountsActivityFragment extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        View rootView = inflater.inflate(R.layout.fragment_accounts_activity, container, false);

        return rootView;
    }
}

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.rastari.salar.mymetarialbank.R;

/**
 * Created by Salar on 9/5/2015.
 */
public class ChartActivityFragment extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        View rootView = inflater.inflate(R.layout.fragment_chart_activity, container, false);

        return rootView;
    }
}

这是ChartActivityFragment.java：

import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.rastari.salar.mymetarialbank.R;

/**
 * Created by Salar on 25/4/2015.
 */
public class AccountsActivityFragment extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        View rootView = inflater.inflate(R.layout.fragment_accounts_activity, container, false);

        return rootView;
    }
}

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.rastari.salar.mymetarialbank.R;

/**
 * Created by Salar on 9/5/2015.
 */
public class ChartActivityFragment extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        View rootView = inflater.inflate(R.layout.fragment_chart_activity, container, false);

        return rootView;
    }
}

这是显而易见的：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.rastari.salar.mymetarialbank" >

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/MyMetarialBank">
        <activity
            android:name=".activity.Login"
            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=".activity.MainActivity"/>
        <activity android:name=".activity.AccountsActivityChart"/>
    </application>

</manifest>

当我运行应用程序时，出现以下错误：

尝试调用虚拟方法“void” 空对象上的android.app.ActionBar.setHomeButtonEnabled（布尔）“” 参考文献

---

如何修复此问题？

尝试actionBar=getSupportActionBar（）；

---

而不是actionBar=getActionBar（）

我想你已经应用了没有动作条的主题。这就是为什么当您获取actionbar实例时，它将为null，并且您在null actionbar实例上调用setHomeButtonEnabled。这就是您收到错误的原因。

您也可以发布您的清单吗？更具体地说，请说出您在活动中使用的主题。这是您的代码还是您复制的？根据您的问题，这里是您的答案，这里是manifest@lalactaly，如果是，我复制的最多@Virus@Lal开发者可以对另一个问题发表评论，需要50%的声誉。所以，让他们试试吧