Question

我发现了这个错误：

java.lang.RuntimeException：无法启动活动ComponentInfo {com.kkk.findyourbook / com.kkk.findyourbook.activities.MainActivity}：java.lang.NullPointerException：尝试调用虚方法＆＃39; android.view .View android.support.v7.widget.Toolbar.findViewById（int）＆＃39;在空对象引用上

引起：java.lang.NullPointerException：尝试调用虚拟   方法＆＃39; android.view.View   android.support.v7.widget.Toolbar.findViewById（INT）＆＃39;在null对象上   参考

这很奇怪，因为它刚刚发生，我的意思是我曾经没有任何问题地运行我的应用程序。

我的onCreate()方法如下所示：

@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    ButterKnife.bind(this);

    getNavigationDrawerItems();

    setupToolbar();
    setupDrawerToggle();

    DrawerItemCustomAdapter adapter = new DrawerItemCustomAdapter(this, R.layout.drawer_item, mNavigationDrawerItems);
    drawerList.setAdapter(adapter);
    drawerList.setOnItemClickListener(new DrawerItemClickListener());

    mActionBar = getSupportActionBar();
    mActionBar.setDisplayHomeAsUpEnabled(false);
    mActionBar.setHomeButtonEnabled(true);
    mActionBar.setDisplayShowTitleEnabled(true);

    assert drawerLayout != null;
    drawerLayout.addDrawerListener(drawerToggle);

    sFragmentManager = getSupportFragmentManager();

    // Check that the activity is using the layout version with
    // the fragment_container FrameLayout
    if (findViewById(R.id.container) != null) {

        // However, if we're being restored from a previous state,
        // then we don't need to do anything and should return or else
        // we could end up with overlapping fragments.
        if (savedInstanceState != null) {
            return;
        }

        // Create a new Fragment to be placed in the activity layout
        Fragment fragment = new SampleFragment();

        // In case this activity was started with special instructions from an
        // Intent, pass the Intent's extras to the fragment as arguments
        //            firstFragment.setArguments(getIntent().getExtras());

        // Add the fragment to the 'fragment_container' FrameLayout
        sFragmentManager.beginTransaction()
            .add(R.id.container, fragment)
            .commit();
    }
}

setupToolbar()方法：

void setupToolbar() {
    setSupportActionBar(toolbar);
    getSupportActionBar().setDisplayShowHomeEnabled(true);
}

在我的片段中：

public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View fragment = inflater.inflate(R.layout.fragment_sample, container, false);
    ButterKnife.bind(this, fragment);

    toolbarInit();

    return fragment;
}

private void toolbarInit() {
    mToolbar = (Toolbar) getActivity().findViewById(R.id.toolbar);

    TextView toolbarTitle = (TextView) mToolbar.findViewById(R.id.toolbarTitle);
    toolbarTitle.setText(getActivity().getResources().getString(R.string.cat_my_books));
}

你能帮我解决这个错误吗？

编辑：

工具栏布局：

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:local="http://schemas.android.com/apk/res-auto"
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:minHeight="?attr/actionBarSize"
    android:background="@color/colorPrimary"
    local:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
    local:popupTheme="@style/ThemeOverlay.AppCompat.Light" >
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="horizontal">
        <ImageView
            android:id="@+id/toolbarIconLeft"
            android:layout_width="32dp"
            android:layout_height="32dp"
            android:layout_gravity="end"
            android:padding="4dp"
            android:src="@drawable/logo"
            android:visibility="gone"
            android:contentDescription="toolbarIcon" />
        <TextView
            android:id="@+id/toolbarTitle"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:layout_gravity="center"
            android:layout_marginRight="8dp"
            android:layout_marginEnd="8dp"
            android:textAlignment="center"
            android:gravity="center_horizontal"
            android:textSize="18sp"
            android:textAllCaps="true"
            android:textColor="@android:color/white"
            android:textStyle="bold" />
        <ImageView
            android:id="@+id/toolbarIcon"
            android:layout_width="32dp"
            android:layout_height="32dp"
            android:layout_gravity="end"
            android:layout_marginRight="12dp"
            android:layout_marginEnd="12dp"
            android:visibility="invisible"
            android:src="@drawable/logo"
            android:contentDescription="toolbarIcon" />
    </LinearLayout>
</android.support.v7.widget.Toolbar>

Android：RuntimeException，无法启动活动ComponentInfo，工具栏错误

0 个答案: