Activity getting Destroyed when calling Fragment

Question

Using Fragment in Class which is sub class of RoboActivity, Crashing application when Fragment Transaction begin;

I am also can't able to use Bottom navigation or Tablayout, maybe it's something relates roboguice.

This is Obd car Scan Application

Code As Below:

  public void onCreate(Bundle savedInstanceState) 

{
            super.onCreate(savedInstanceState);

            SpeedButton.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Fragment selectedFragment = null;
                    selectedFragment = new SpeedFragment();
                    AppCompatActivity activity=new AppCompatActivity();

                    if (!isFinishing() && !isDestroyed()) {
                        FragmentTransaction ft =activity.getSupportFragmentManager()
                                .beginTransaction();
                        ft.replace(R.id.fragment_container, selectedFragment);
                        ft.commit();
                    }
                }
            });
      }

Log:

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.quad14.obdnewtry, PID: 7878
    java.lang.IllegalStateException: Activity has been destroyed
        at android.support.v4.app.FragmentManagerImpl.enqueueAction(FragmentManager.java:2114)
        at android.support.v4.app.BackStackRecord.commitInternal(BackStackRecord.java:683)
        at android.support.v4.app.BackStackRecord.commit(BackStackRecord.java:637)
        at com.quad14.obdnewtry.activity.MainActivity$3.onClick(MainActivity.java:272)
        at android.view.View.performClick(View.java:5637)
        at android.view.View$PerformClick.run(View.java:22429)
        at android.os.Handler.handleCallback(Handler.java:751)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:154)
        at android.app.ActivityThread.main(ActivityThread.java:6119)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)

Layout: only Fragment related component are added below

 <FrameLayout
            android:id="@+id/fragment_container"
            android:layout_width="match_parent"
            android:layout_height="80dp"
            />

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/buttonlinear"
            android:orientation="horizontal">
            <Button
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Speed"
                android:id="@+id/speedbtid"/>

            <Button
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Rpm"
                android:id="@+id/rpmbtid"/>
            <Button
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Total Km"
                android:id="@+id/distanbtid"/>

        </LinearLayout>

    </LinearLayout>

Answer 1

If your activity extends Activity your fragment should be android.app.Fragment. Then use code below

 android.app.FragmentTransaction ft =getFragmentManager()
                            .beginTransaction();
                    ft.replace(R.id.fragment_container, selectedFragment);
                    ft.commit();

else if your activity extends AppCompactActivity your fragment should be android.support.v4.app.Fragment.Then this code will work

 FragmentTransaction ft =getSupportFragmentManager()
                            .beginTransaction();
                    ft.replace(R.id.fragment_container, selectedFragment);
                    ft.commit();

Answer 2

Instead of creating object for activity like AppCompatActivity activity=new AppCompatActivity(); and using it to get fragment manager.

You can get fragment manager from activity context something like this YourActivityname.this.getFragmentManager();

Answer 3

尝试使用

getContext().getSupportFragmentManager().beginTransaction();