Question

我正在尝试在两个片段之间实现导航。一个是我的应用程序的默认视图，它只包含带有自己项目的RecyclerView，另一个是带有TableLayout作为子项的ScrollView。应用正确地从我的ViewAdverts片段切换到AddAdvert，但是当我想要返回时，会出现异常和应用崩溃：

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: pl.polsl.elektr.quicktrade011, PID: 14676
    java.lang.IllegalStateException: ScrollView can host only one direct child
    at android.widget.ScrollView.addView(ScrollView.java:248)
    at android.support.design.widget.BaseTransientBottomBar.showView(BaseTransientBottomBar.java:444)
    at android.support.design.widget.BaseTransientBottomBar$1.handleMessage(BaseTransientBottomBar.java:185)
    at android.os.Handler.dispatchMessage(Handler.java:98)
    at android.os.Looper.loop(Looper.java:135)
    at android.app.ActivityThread.main(ActivityThread.java:5254)
    at java.lang.reflect.Method.invoke(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:372)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

我不知道为什么只有当从ScrollView返回到RecyclerView时才出现该错误，而当默认片段包含RecyclerView时，不会在app启动时出现。以下是我的.java和.xml文件： 5 files at Gist

Answer 1

片段A

    FragmentManager fragmentManager = getSupportFragmentManager();
    FragmentTransaction fragmentTransaction = 
    fragmentManager.beginTransaction();
    fragment = new DashboardFragment();
    fragmentTransaction.replace(R.id.container, fragment).addToBackStack(null).commit();

片段B

    rootview.setFocusableInTouchMode(true);
    rootview.requestFocus();
    rootview.setOnKeyListener(new View.OnKeyListener() {
        @Override
        public boolean onKey(View v, int keyCode, KeyEvent event) {

            if (event.getAction() == KeyEvent.ACTION_UP && keyCode == KeyEvent.KEYCODE_BACK) {
                // DO WHAT YOU WANT ON BACK PRESSED
                getFragmentManager().popBackStack();
                return true;
            } else {
                return false;
            }
        }
    });

片段切换 - 无法从后台返回

1 个答案: