android - 调用 fragment 时 Activity 被破坏

Question

在子类的类中使用 fragment RoboActivity， fragment 时崩溃应用程序 交易开始；

我也无法使用底部导航或 Tablayout，可能跟roboguice有关。

这是 Obd 汽车扫描应用程序

代码如下:

  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();
                    }
                }
            });
      }

日志:

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:下面只添加了Fragment相关的组件

 <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

如果您的 Activity 扩展了 Activity，您的 fragment 应该是 android.app.Fragment。然后使用下面的代码

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

否则，如果您的 Activity 扩展 AppCompactActivity，您的 fragment 应该是 android.support.v4.app.Fragment。那么这段代码将起作用

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