Question

我想在导航入口处使用数据绑定。当我在活动中使用fragment（android：name =“ NavHostFragment”）时，程序可以正常运行；但是当我在活动（android：name =“ NavHostFragment”）+数据绑定中使用片段时，该程序将无法运行。请帮助我，希望在导航入口处使用数据绑定，请告诉我如何使用它，谢谢！！

例外：

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.appnavigationtodo/com.example.appnavigationtodo.MainActivity}: android.view.InflateException: Binary XML file line #21: Binary XML file line #21: Error inflating class fragment
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3092)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3235)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1926)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:6990)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1445)
     Caused by: android.view.InflateException: Binary XML file line #21: Binary XML file line #21: Error inflating class fragment
     Caused by: android.view.InflateException: Binary XML file line #21: Error inflating class fragment
     Caused by: java.lang.IllegalArgumentException: Binary XML file line #21: Duplicate id 0x7f080050, tag null, or parent id 0xffffffff with another fragment for androidx.navigation.fragment.NavHostFragment
        at androidx.fragment.app.FragmentManagerImpl.onCreateView(FragmentManager.java:3752)
        at androidx.fragment.app.FragmentController.onCreateView(FragmentController.java:120)
        at androidx.fragment.app.FragmentActivity.dispatchFragmentsOnCreateView(FragmentActivity.java:405)
        at androidx.fragment.app.FragmentActivity.onCreateView(FragmentActivity.java:387)
        at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:780)
        at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:730)
        at android.view.LayoutInflater.rInflate(LayoutInflater.java:863)
        at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:824)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:515)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:374)
        at androidx.appcompat.app.AppCompatDelegateImpl.setContentView(AppCompatDelegateImpl.java:469)
        at androidx.appcompat.app.AppCompatActivity.setContentView(AppCompatActivity.java:140)
        at androidx.databinding.DataBindingUtil.setContentView(DataBindingUtil.java:303)
        at androidx.databinding.DataBindingUtil.setContentView(DataBindingUtil.java:284)
        at com.example.appnavigationtodo.MainActivity.onCreate(MainActivity.java:25)
        at android.app.Activity.performCreate(Activity.java:7326)
        at android.app.Activity.performCreate(Activity.java:7317)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1271)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3072)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3235)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1926)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:6990)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1445)

MainActivity.java：

public class MainActivity extends AppCompatActivity {
    private  ActivityMainBinding activityMainBinding;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        activityMainBinding = DataBindingUtil.setContentView(this,R.layout.activity_main);
    }
}

activity_main.xml：

<layout 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">
    <data>
    </data>
    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        <androidx.appcompat.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:theme="@style/ToolbarTheme" />
        <fragment
            android:id="@+id/fragmentMain"
            android:name="androidx.navigation.fragment.NavHostFragment"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1"
            app:defaultNavHost="true"
            app:navGraph="@navigation/nav_main" />
        <com.google.android.material.bottomnavigation.BottomNavigationView
            android:id="@+id/bottomNavigationView"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:menu="@menu/menu_bottom_navigation_view" />
    </LinearLayout>
</layout>

Answer 1

您要两次致电my @files = map { $_->[0] } sort { $a->[1] cmp $b->[1] || $a->[0] cmp $b->[0] } map { [ $_, Digest::SHA->new(1)->addfile($_)->digest ] } @ARGV;，一次是致电setContentView，第二次是setContentView。相反，只需使用DataBindingUtil.setContentView()，它会在内部自行调用DataBindingUtil.setContentView()：

setContentView()

如何在活动中使用导航条目（NavHostFragment）和数据绑定？

1 个答案: