将导航抽屉活动扩展到其他活动

我正在尝试创建一个导航抽屉活动，以便我可以按照此问题中给出的答案扩展该活动并在所有活动中使用该菜单链接但我的测试应用程序不断崩溃，这是我的代码：

基本活动.java

public class BaseActivity extends Activity {
    public DrawerLayout drawerLayout;
    public ListView drawerList;
    public String[] layers;
    private ActionBarDrawerToggle drawerToggle;
    protected void onCreate(Bundle savedInstanceState) {
        // R.id.drawer_layout should be in every activity with exactly the same
        // id.
        drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawerToggle = new ActionBarDrawerToggle((Activity) this, drawerLayout,
                R.drawable.ic_drawer, 0, 0) {
            public void onDrawerClosed(View view) {
                getActionBar().setTitle(R.string.hello_world);
            }
            public void onDrawerOpened(View drawerView) {
                getActionBar().setTitle(R.string.hello_world);
            }
        };
        drawerLayout.setDrawerListener(drawerToggle);
        getActionBar().setDisplayHomeAsUpEnabled(true);
        getActionBar().setHomeButtonEnabled(true);
        layers = getResources().getStringArray(R.array.planets_array);
        drawerList = (ListView) findViewById(R.id.left_drawer);
        drawerList.setAdapter(new ArrayAdapter<String>(this,
                R.layout.drawer_list_item, android.R.id.text1, layers));
    }
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if (drawerToggle.onOptionsItemSelected(item)) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
    @Override
    protected void onPostCreate(Bundle savedInstanceState) {
        super.onPostCreate(savedInstanceState);
        drawerToggle.syncState();
    }
    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        drawerToggle.onConfigurationChanged(newConfig);
    }
}

主要活动.java

public class MainActivity extends BaseActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_profile);
    }
}

activity_profile.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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".ProfileActivity" >
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />
</RelativeLayout>

日志猫

03-03 01:22:18.031: D/AndroidRuntime(27902): Shutting down VM
03-03 01:22:18.031: W/dalvikvm(27902): threadid=1: thread exiting with uncaught exception (group=0x2b542210)
03-03 01:22:18.041: E/AndroidRuntime(27902): FATAL EXCEPTION: main
03-03 01:22:18.041: E/AndroidRuntime(27902): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.slider/com.example.slider.MainActivity}: java.lang.NullPointerException
03-03 01:22:18.041: E/AndroidRuntime(27902):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1967)
03-03 01:22:18.041: E/AndroidRuntime(27902):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1992)
03-03 01:22:18.041: E/AndroidRuntime(27902):    at android.app.ActivityThread.access$600(ActivityThread.java:127)
03-03 01:22:18.041: E/AndroidRuntime(27902):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1158)
03-03 01:22:18.041: E/AndroidRuntime(27902):    at android.os.Handler.dispatchMessage(Handler.java:99)
03-03 01:22:18.041: E/AndroidRuntime(27902):    at android.os.Looper.loop(Looper.java:137)
03-03 01:22:18.041: E/AndroidRuntime(27902):    at android.app.ActivityThread.main(ActivityThread.java:4441)
03-03 01:22:18.041: E/AndroidRuntime(27902):    at java.lang.reflect.Method.invokeNative(Native Method)
03-03 01:22:18.041: E/AndroidRuntime(27902):    at java.lang.reflect.Method.invoke(Method.java:511)
03-03 01:22:18.041: E/AndroidRuntime(27902):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
03-03 01:22:18.041: E/AndroidRuntime(27902):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
03-03 01:22:18.041: E/AndroidRuntime(27902):    at dalvik.system.NativeStart.main(Native Method)
03-03 01:22:18.041: E/AndroidRuntime(27902): Caused by: java.lang.NullPointerException
03-03 01:22:18.041: E/AndroidRuntime(27902):    at com.example.slider.BaseActivity.onCreate(BaseActivity.java:35)
03-03 01:22:18.041: E/AndroidRuntime(27902):    at com.example.slider.MainActivity.onCreate(MainActivity.java:12)
03-03 01:22:18.041: E/AndroidRuntime(27902):    at android.app.Activity.performCreate(Activity.java:4465)
03-03 01:22:18.041: E/AndroidRuntime(27902):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
03-03 01:22:18.041: E/AndroidRuntime(27902):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1931)
03-03 01:22:18.041: E/AndroidRuntime(27902):    ... 11 more

在主活动中，您必须在setContentView（）之后调用super.onCreate（savedInstanceState）

问题似乎是基类不知道布局。不知道它如何或为什么对其他人有用，而不必做这样的事情。但我是安卓新手。

我遇到了同样的错误，并通过 onCreate 将我的布局传递到基础来解决。

所以在基础中，我将onCreate修改为这样：

protected void onCreate(Bundle savedInstanceState, int resLayoutID)
{
    super.onCreate(savedInstanceState);
    setContentView(resLayoutID);

然后，从我的新活动中，我有这个：

@Override
protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState, R.layout.my_activity);

我的基本代码现在可以工作，而不是保持空值：

drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
drawerList = (ListView) findViewById(R.id.left_drawer);

顺便说一句，这个结果是由一个朋友向我建议的，它对我有用。

在父类BaseActivity上：

声明protected abstract int getLayoutId();
onCreate（）我添加了行
```
setContentView(getLayoutId());
```

现在在你的子类 MainActivity 上实现它，如下所示：

 protected int getLayoutId() {
    return R.layout.activity_profile;
}

如果您知道更好的解决方案，请告诉我。

正如 oli 所建议的，您需要在主活动中调用 setContentView（R.layout.activity_view）。

一旦在主活动中设置了内容视图，就必须调用BaseActivity的onCreate，如下所示：

public class BaseActivity extends Activity {
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // REST Navigation drawer initialization
    }
}

public class MainActivity extends BaseActivity {
    protected void onCreate(Bundle savedInstanceState) {
        setContentView(R.layout.activity_view);
        super.onCreate(savedInstanceState);
        // REST APPLICATION CODE
    }
}

你的xml文件应该看起来像这样，取自安卓网站：http://developer.android.com/training/implementing-navigation/nav-drawer.html

<android.support.v4.widget.DrawerLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <!-- The main content view -->
    <FrameLayout
        android:id="@+id/content_frame"
        android:layout_width="match_parent"
        android:layout_height="match_parent" >
        <!-- Add content here -->
    </FrameLayout>
    <!-- The navigation drawer -->
    <ListView android:id="@+id/left_drawer"
        android:layout_width="240dp"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        android:choiceMode="singleChoice"
        android:divider="@android:color/transparent"
        android:dividerHeight="0dp"
        android:background="#111"/>
</android.support.v4.widget.DrawerLayout>

在你的主活动中，只需将设置setContentView(R.layout.activity_main)放在前面

super.onCreate(savedInstanceState);

如下所示：

@Override
protected void onCreate(Bundle savedInstanceState) {
    setContentView(R.layout.activity_profile);
    super.onCreate(savedInstanceState);
}

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