动画仍在淡入/淡出时，BottomNavigation单击后崩溃

Question

我有BottomNavigation和4个片段。单击BottomNavigation符号后，应用程序崩溃，但前提是动画（淡入/淡出）仍在进行中。如果我在代码中禁用动画，如下所示：/setCustomAnimations(R.anim.fade_in，R.anim.fade_out）。 /一切正常，但没有动画。我想保留动画。请问我该如何解决？

这是我的BottomNavigation代码：

public class MainActivity extends AppCompatActivity implements BottomNavigationView.OnNavigationItemSelectedListener {

BottomNavigationView bottomNavigationView;

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

    bottomNavigationView = findViewById(R.id.bottom_Navigation_View);

    bottomNavigationView.setOnNavigationItemSelectedListener(this);

    bottomNavigationView.setSelectedItemId(R.id.navigation_partOne);
}

partOne partOneFragment = new partOne();
partTwo partTwoFragment = new partTwo();
partThree partThreeFragment = new partThree();
partFour partFourFragment = new partFour();

@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {

    switch (item.getItemId()){
        case R.id.navigation_partOne:
            getSupportFragmentManager().beginTransaction()./*setCustomAnimations(R.anim.fade_in, R.anim.fade_out).*/replace(R.id.container, partOneFragment).commit();
            return true;

        case R.id.navigation_partTwo:
            getSupportFragmentManager().beginTransaction()./*setCustomAnimations(R.anim.fade_in, R.anim.fade_out).*/replace(R.id.container, partTwoFragment).commit();
            return true;

        case R.id.navigation_partThree:
            getSupportFragmentManager().beginTransaction()./*setCustomAnimations(R.anim.fade_in, R.anim.fade_out).*/replace(R.id.container, partThreeFragment).commit();
            return true;

        case R.id.navigation_partFour:
            getSupportFragmentManager().beginTransaction()./*setCustomAnimations(R.anim.fade_in, R.anim.fade_out).*/replace(R.id.container, partFourFragment).commit();
            return true;
    }
    return false;
 }
}

为了完整起见，这是我的fade_in.xml：

    <?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
    <alpha android:fromAlpha="0"
        android:toAlpha="1"
        android:duration="300"
        android:interpolator="@android:anim/accelerate_interpolator"/>
</set>

Logcat中的错误：

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.exerciseexample, PID: 17519
    java.lang.IllegalStateException: Restarter must be created only during owner's initialization stage
        at androidx.savedstate.SavedStateRegistryController.performRestore(SavedStateRegistryController.java:58)
        at androidx.fragment.app.Fragment.performCreate(Fragment.java:2585)
        at androidx.fragment.app.FragmentManagerImpl.moveToState(FragmentManagerImpl.java:838)
        at androidx.fragment.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManagerImpl.java:1238)
        at androidx.fragment.app.FragmentManagerImpl.moveToState(FragmentManagerImpl.java:1303)
        at androidx.fragment.app.BackStackRecord.executeOps(BackStackRecord.java:439)
        at androidx.fragment.app.FragmentManagerImpl.executeOps(FragmentManagerImpl.java:2079)
        at androidx.fragment.app.FragmentManagerImpl.executeOpsTogether(FragmentManagerImpl.java:1869)
        at androidx.fragment.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManagerImpl.java:1824)
        at androidx.fragment.app.FragmentManagerImpl.execPendingActions(FragmentManagerImpl.java:1727)
        at androidx.fragment.app.FragmentManagerImpl$2.run(FragmentManagerImpl.java:150)
        at android.os.Handler.handleCallback(Handler.java:739)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:145)
        at android.app.ActivityThread.main(ActivityThread.java:5832)
        at java.lang.reflect.Method.invoke(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:372)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194)

compileSdkVersion为29；相关的依赖项是implementation 'androidx.appcompat:appcompat:1.1.0'：我已经通过降级这些版本进行了尝试。

提前感谢！

Answer 1

尝试为每个片段在setCustomAnimations（）之后添加AddToBackStack（null）。

  getSupportFragmentManager().beginTransaction().setCustomAnimations(R.anim.fade_in, 
 R.anim.fade_out).AddToBackStack(null).replace(R.id.container, 
  partOneFragment).commit();

另一种解决方案，您可以尝试将库版本更改为androidx.appcompat：appcompat：1.0.2。