Fragment中集成Navigation Drawer添加Drawer Toggle后应用崩溃如何解决？

核心崩溃原因 #

崩溃主要来自以下几个常见错误点：

• 承载Fragment的Activity使用了自带ActionBar的主题，与Fragment中动态设置的Toolbar冲突
• 在onCreateView中直接操作宿主Activity，没有做空指针判断，Fragment未完全绑定到Activity时触发空指针异常
• 导包错误，混用了androidx和旧版support包的DrawerLayout、ActionBarDrawerToggle类
• 未在strings.xml中定义nav_open_drawer、nav_close_drawer对应的字符串资源，触发资源找不到异常

修复步骤 #

1. 修改Activity主题
   确保承载该Fragment的Activity在AndroidManifest.xml中配置的主题为不带ActionBar的类型，示例：

<activity
    android:name=".YourHostActivity"
    android:theme="@style/Theme.MaterialComponents.DayNight.NoActionBar" />

2. 调整Fragment代码逻辑
   将Drawer相关初始化逻辑移到onViewCreated中执行，增加非空判断，补充生命周期回调处理状态同步和资源释放，修改后的代码如下：

// 导包请确保全为androidx版本
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import androidx.drawerlayout.widget.DrawerLayout;
import androidx.appcompat.app.ActionBarDrawerToggle;
import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.content.res.Configuration;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;

public class TestListFragment extends Fragment {
    private RecyclerView testRecycler;
    private String[] names;
    private DrawerLayout drawer;
    private ActionBarDrawerToggle toggle;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // 允许Fragment参与菜单创建
        setHasOptionsMenu(true);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_test_list, container, false);
    }

    @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        // 先校验宿主Activity有效性
        AppCompatActivity activity = (AppCompatActivity) getActivity();
        if (activity == null || activity.isFinishing() || activity.isDestroyed()) {
            return;
        }

        Toolbar toolbar = view.findViewById(R.id.toolbar);
        activity.setSupportActionBar(toolbar);

        drawer = view.findViewById(R.id.drawer_layout);
        toggle = new ActionBarDrawerToggle(activity, drawer, toolbar, R.string.nav_open_drawer, R.string.nav_close_drawer);
        drawer.addDrawerListener(toggle);
        toggle.syncState();

        testRecycler = view.findViewById(R.id.test_recycler);
        LinearLayoutManager layoutManager = new LinearLayoutManager(activity);
        testRecycler.setLayoutManager(layoutManager);

        names = new String[Test.testData.length];
        for(int i = 0; i < names.length; i++) {
            names[i] = Test.testData[i].getTitle();
        }

        TestAdapter adapter = new TestAdapter(names);
        testRecycler.setAdapter(adapter);
    }

    @Override
    public void onConfigurationChanged(@NonNull Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        if (toggle != null) {
            toggle.onConfigurationChanged(newConfig);
        }
    }

    @Override
    public void onDestroyView() {
        // 移除监听器避免内存泄漏
        if (drawer != null && toggle != null) {
            drawer.removeDrawerListener(toggle);
        }
        super.onDestroyView();
    }
}

3. 校验字符串资源
   打开res/values/strings.xml，确认存在以下两个字符串定义：

<string name="nav_open_drawer">打开侧滑菜单</string>
<string name="nav_close_drawer">关闭侧滑菜单</string>

完成以上修改后即可解决崩溃问题。

内容的提问来源于stack exchange，提问作者fl4me