android - 如何手动调用 onSaveInstanceState()

Question

我正在编写一个程序，我在同一个 Activity 中调用多个布局，但后来我注意到当我切换布局时，切换之前所做的更改不会恢复并且 onSavedInstanceState(Bundle outState) 是没有叫。我已尝试手动调用该方法，但无法获取 Bundle outState。

所以真正的问题是:我如何获取和存储要在我选择的时间调用和/或恢复的 Activity 的当前状态？

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_contact_view);
// more code
}

@Override
public void onBackPressed() {
    if (layoutId == R.layout.activity_contact_view) exit();
    else if (layoutId == R.layout.main) {
        Toast.makeText(NsdChatActivity.this, "Successful back button action", Toast.LENGTH_SHORT).show();
        setContentView(R.layout.activity_contact_view);
        refreshContactList();
    }
}

然后从一个单独的类

public void updateList(final int found) {
    LinearLayout layxout = (LinearLayout) ((Activity)mContext).getWindow().getDecorView().findViewById(R.id.others);
    TextView t = new TextView(mContext);
    t.setClickable(true);
    t.setText(found + ". " + activity.sNames.get(found));
    t.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT));
    t.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            //show chat view
            activity.setContentView(R.layout.main);
            TextView name = (TextView)activity.findViewById(R.id.clientName);
            name.setText(activity.sNames.get(found).split(" \\(")[0]);
            final ScrollView scroll = (ScrollView)activity.findViewById(R.id.scroll);
            scroll.setOnFocusChangeListener(new View.OnFocusChangeListener() {
                @Override
                public void onFocusChange(View view, boolean b) {
                    scroll.fullScroll(View.FOCUS_DOWN);
                }
            });
        }
    });
    layxout.addView(t);
}

Answer 1

我可能会迟到，但你可以做的是保持你作为类(class)成员的状态。这样您就可以随时恢复状态。

Bundle mState;

@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
    // Save the state
    savedInstanceState = mState;
    super.onSaveInstanceState(savedInstanceState);
}
@Overrite
public void onRestoreInstanceState(Bundle savedInstance){
    mState = savedInstance;
    Restore();
}

public void Restore(){
    //access your state and restore
}

此外，您不应该使用 setContentView 在 View 之间切换，这是一种昂贵的方式。您可能想查看 ViewSwitcher或 ViewFlipper或者以某种方式实现 Fragments。