相关疑难解决方法(0)

我相信当重写getItemPosition(Object object)以重新排序页面时,FragmentStatePagerAdapter的行为不正确.

下面是一个简单的例子.在初始状态中,页面的顺序是{A,B,C}.在呼叫时toggleState(),页面的顺序变为{A,C,B}.通过覆盖getItemPosition(Object object),我们确保正在查看的当前页面(A,B或C)不会更改.

public static class TestPagerAdapter extends FragmentStatePagerAdapter {
    private boolean mState = true;

    public TestPagerAdapter(FragmentManager fragmentManager) {
        super(fragmentManager);
    }

    @Override
    public int getCount() {
        return 3;
    }

    private void toggleState() {
        mState = !mState;
        notifyDataSetChanged();
    }

    private String getLabel(int position) {
        switch (position) {
            case 0:
                return "A";
            case 1:
                return mState ? "B" : "C";
            default:
                return mState ? "C" : "B";
        }
    }

    @Override
    public int getItemPosition(Object object) { …