java - 按下返回键后恢复上次打开的 pdf 页面

Question

按下后退键后，我实现了此代码以恢复我在 PDF 文档中最后打开的页面。不幸的是，它仍然加载第一页。

    pdfView1 = findViewById(R.id.pdfViewer1);
    pdfView1.fromAsset("cpgTest1.pdf")
            .scrollHandle(new DefaultScrollHandle(this))
            .defaultPage(currentPage)
            .onPageChange(this)
            .load();
}

@Override
public void onPageChanged(int page, int pageCount)
{
    currentPage = page;
}

@Override
public void loadComplete(int nbPages)
{
    if (currentPage >= 0)
    {
        pdfView1.jumpTo(currentPage);
    }}


@Override
public void onSaveInstanceState(Bundle outState)
{
    super.onSaveInstanceState(outState);
    outState.putInt(KEY_CURRENT_PAGE, currentPage);
}

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState)
{
    super.onRestoreInstanceState(savedInstanceState);
    currentPage = savedInstanceState.getInt(KEY_CURRENT_PAGE);
}

}

任何想法？