Android 从导航抽屉调用片段
我有一个导航抽屉,它由n个菜单组成,点击菜单我需要打开一个特定的片段。首先,我尝试了它的活动和意图。在使用碎片的情况下,它看起来不太好。我通过id选择它们,并从活动中调用片段。在这个片段中,我使用了饼图,在饼图中它抛出空指针异常。我尝试过从get view更改,因为它只在Oncreate view之后实例化。但没有结果Android 从导航抽屉调用片段,android,android-fragments,Android,Android Fragments,我有一个导航抽屉,它由n个菜单组成,点击菜单我需要打开一个特定的片段。首先,我尝试了它的活动和意图。在使用碎片的情况下,它看起来不太好。我通过id选择它们,并从活动中调用片段。在这个片段中,我使用了饼图,在饼图中它抛出空指针异常。我尝试过从get view更改,因为它只在Oncreate view之后实例化。但没有结果 public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState)
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
pieChart1 = (PieChart) getView().findViewById(R.id.piechart1);
pieChart2 = (PieChart) getView().findViewById(R.id.piechart2);
下面是一个有助于理解的示例代码。 首先用OnCreate()中的片段替换activity_main.xml内容: 然后在onNavigationItemSelected()中将此HomeFragment替换为其他HomeFragment: 在content\u main.xml中添加框架布局,并将其id设置为“content\u frame”
Ya谢谢,我想切换到Fragment是可行的,它只是在这行pieChart1=(PieChart)getView()上显示空指针异常;pieChart2=(PieChart)getView().findViewById(R.id.pieChart2)`fm.beginTransaction().replace(R.id.content_frame,新设置片段()).commit();在内容框架的这一行中,我们应该给出布局我不能添加我的布局更改了所有内容它仍然强制在同一行上关闭哪个错误?是NullObjectReference吗?是java.lang.NullPointerException:尝试调用虚拟方法'android.view.view android.view.view.findViewById(int)@tahsinRupamdid是否添加任何视图?
FragmentManager fm = getFragmentManager();
fm.beginTransaction().replace(R.id.content_frame, new HomeFragment()).commit();
@Override
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
int id = item.getItemId();
if (id == R.id.nav_home) {
// Handle the camera action
FragmentManager fm = getFragmentManager();
fm.beginTransaction().replace(R.id.content_frame, new HomeFragment()).commit();
} else if (id == R.id.nav_current_order) {
FragmentManager fm = getFragmentManager();
fm.beginTransaction().replace(R.id.content_frame, new MyCurrentOrderFragment(),"Tag").commit();
} else if (id == R.id.nav_received_images) {
FragmentManager fm = getFragmentManager();
fm.beginTransaction().replace(R.id.content_frame, new HistoryFragment()).commit();
} else if (id == R.id.nav_rate_app) {
FragmentManager fm = getFragmentManager();
fm.beginTransaction().replace(R.id.content_frame, new RateOurAppFragment()).commit();
} else if (id == R.id.nav_help) {
FragmentManager fm = getFragmentManager();
fm.beginTransaction().replace(R.id.content_frame, new HelpFragment()).commit();
} else if (id == R.id.nav_settings) {
FragmentManager fm = getFragmentManager();
fm.beginTransaction().replace(R.id.content_frame, new SettingsFragment()).commit();
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
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"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="bd.com.chalo.dsstudio.MainActivity"
tools:showIn="@layout/app_bar_main">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hello World!"
android:visibility="gone" />
<FrameLayout
android:id="@+id/content_frame"
android:layout_width="match_parent"
android:layout_height="match_parent"></FrameLayout>
</RelativeLayout>